UPDATES, NOTES AND REMARKS by Dipl. Biol. Rainer Schulte

 

The manuscript of Vol. 1 PDF Peru is ready since 1999. Still we could not settle terms with a new publisher. Especially important is the Disease chapter of this book- because the retarded publishing could NOT WARN the frog keeper community how to act in front of the Chytrid Holocaust- and now, most breeders in Europe have infected frogs or installations- which are a great danger to Europe's native amphibians: every drop of water coming from an Chytrid infected terrarium is an extremely DANGEROUS BIOHAZARD! Today we can treat Chytrids in terrarias- but this is NOT possible in the nature. Once the zoospores get into natural Ecosystems- they start their killing wave if the temperature is optimum for the disease. At the moment, Chytrids are affecting severely commercial scientific-frog producing farms in the USA- with TOTAL losses of reproductors and new diseases are showing up, which even can be transmitted from frogs to Humans (Chlamydias).

All breeders which use the strategies published in the first green Ulmer book (Schulte, R.: Frösche und Kröten, Ulmer Verlag Stuttgart) and make a three months quarantine with their new frogs had no problems. Today, most frogs coming from Centro- America, parts of the USA, and all from Australia can be considered a BIOHAZARD and must be checked for Chytrids- how see the chapter below. The fungus kills a frog in about three weeks or a little more- so extreme caution with new purchases from doubtful origins (smuggled frogs) is necessary.
We have the first observations (not yet scientifically tested), that the chytrids may now even kill canopy frogs via the contamination of the home bromeliads of dart frogs by means of infected Hylids! The extreme and fast population declines of altitude species Dendrobates arboreus and Dendrobates speciosus are first indicators, that something weird is going on. Chytrids have been recorded from Ecuador (Luis Coloma, PUCE), but this must be checked in detail.

INIBICO is preparing the RESCUE PROJECT for all Epipedobatids of the tricolor group, which might go extinct first if the Chytrid is really present in ECUADOR. Strategy includes a detection and mapping of all existing species and variants, a field management and constant population monitoring with near by living and especially trained campesinos and the setup of two independent intensive breeding facilities, where reproductor groups of all variants will be maintained and reproduced.
Another typical problem of ECUADOR is the ongoing Ecodestruction of the Chocoan rainforest belt reaching down to Central West Ecuador. See Sat image in the thesis of Peter Soegaard, Denmark, about D. histrionicus at BILSA RESERVE: only 2-3% of the once present 100% of Choco rainforests are barely surviving in Ecuador! This tremendous Ecodestruction surely has wiped out forever dozens of variants of D. histrionicus. An urgent mapping of the remnant populations & color morphs and the start of the ZIRA management is necessary to save the last barely surviving frogs. One might never forget, that the Poison Dart frogs are important species and their toxins can provide the basis for new medicines worth millions of US$ in biochemical and pharmaceutical patents! See the example of the Epibatidin painkiller discovered from E. tricolor in Ecuador.
The author also indicates, that among the histrionicus frogs commonly treated as a unit with female transport and obligatory egg feeding exist copy species which have a male transport and possibly the original omnivore tadpoles known from D. mysteriosus. Those data coming from long term terrarium observations in the Netherlands (J. Rademaker, Dendrobatidae Netherlands 1990, Vol. 7-12,p. 77 ff) must be checked in the field. The first evidence that a "histrionicus" frog lives at West Ecuador, which maintains the ancient white spot pattern of the precursor and missing link species D. mysteriosus is another proof, that not all what looks like a D. histrionicus might be counted to this group! Details see the D. mysteriosus Rescue Project Manual (Schulte, R: 2000, 19 pp., figs., which can be ordered upon request from inibico@terra.com.pe as a WINZIP file).

As mentioned in Vol. 2, new Dendrobatids show up at all corners of Peru and our continent at the moment- and the author suspects, that only in Peru some 20 species must be described in the next three years. Newest research by us and other Peruvian biologists brought up two more completely different variants of E. bassleri, two possibly new Epipedobates of the femoralis group without signal spots, one new arboreal Dendrobates, one new member of the azureiventris group and one NEW GENUS of Poison Dart frogs exist here and their photos are stored in our computer or will be published in the Epipedobates update.

At the INIBICO lab we could proceed with the hybridization of the yellow "D. ventrimaculatus" from Iquitos and the orange D. amazonicus from the White Sand Ecosystems near Iquitos: first tadpoles show strangest patterns and are much smaller than normal tadpoles and their yellow dorsal dot color is present even in earliest GOSNER stages. This indicates, that the two species are different and under normal circumstances do not share the habitat or interbreed. D. ventrimaculatus lives OUTSIDE the White Sands in most cases and D. amazonicus inside, sharing the habitat with D. reticulatus. D. amazonicus is arboreal, while D. reticulatus is terrestrial. Extremely arboreal is also the Iquitos -D. ventrimaculatus- those frogs go up into the highest canopies.
Our newest field research brought the surprise, that yellow to orange "Y " design D. ventrimaculatus are also present on the East bank of the Amazon, while some frogs from this side like D. flavovittatus could not jump this 4 km wide riverine barrier. This will mean, that the Unit D. ventrimaculatus, the REAL D. quinquevittatus (see Schulte 1999), D. duellmani and the chest band species of the D. lamasi-D. vanzolinii stock could jump the Amazon -Ucayali barrier.
More data and the photos are included in the Update paper SCHULTE, R. (in press): Species and Variants of the Genus Dendrobates from Peru and Adjacent Areas, 80 pp, 120 color photos. Some changes are included in this paper in reference to the D. amazonicus- D. ventrimaculatus group. For interested readers, the group leader is now D. ventrimaculatus, but D. amazonicus (within the D. ventrimaculatus unit) is maintained as an endemic species of the Iquitos White Sand refuge (Hybridization experiments above and our Molecular genetic data in progress support fully this position).

Another success of the Author was, to include the Dendrobatid frogs among others as Key Species for RAP surveys of new rainforest to be used in the big Finnish- Peruvian "Biodiversity of the Amazon (BIODAMAZ)" Project at Iquitos. People interested to know those new KEY species selected during two workshops can order the Results Document from BIODAMAZ@iiap.org.pe or via our Email.
A great help for this new strategy was Vol. 2 of the PDF Peru- and the Update paper- which allow us now to proceed with a very detailed VARIANT ANALYSIS, getting extraordinary and mostly ancient rainforest refuges detected in only a few hours of field work! We are preparing the Field Guide to Lowland Species & Variants of Dendrobatids of the Peruvian Amazon Range (Altitude up to 500 m), the basic field document for the BIODAMAZ Project.
The author received a copy of the critics to Vol. 2, made by Stefan Lötters (DRACO Journal). Very amusing and a fine attempt of revanche, because of shifting E. rubriventris into subspecies level of E. hahneli, but it is not the problem of the author, that the knowledge of those people does not reach the necessary level to keep pace with the systematic situation of the Peruvian Poison Dart frogs and therefore they also can´t check the veracity of the statements made in Vol. 2, which are the results of 20 years of field work under severe conditions, two laboratories to breed and keep poison dart frogs and quite a lot of preserved material stored in Peru. The only paper, which escaped our lit survey from the rainforest here was the one of Myers, Rodriguez & Icochea 1998 of Epipedobates simulans. The author beg pardon for this failure- but nobody is perfect- especially under those conditions we have to work here without Scientific literature server access, without University literature search machines and museum loaning service, without sonagram programs and with only limited funds available. To be able to present a book treating 80 % of the Peruvian species under such conditions even seems a miracle to the author.
If the guys in Germany feel confused about the systematic situation, they may consult our molecular genetic papers coming out soon, which fit perfectly with my findings. The author does not accept any more "common museum data" in Poison Dart frog systematics, because the lot of copy species present and even natural hybrids can be defined only by using molecular genetic data obtained with three to four markers- and not only with two used by Vences et al. 2000- causing severe failures within the relationships of Dendrobatid species!
And the author DID not include the Colostethus, because Peru holds more than 60 species- San Martin alone a min. of 16. The papers and the book about the Colostethus are in progress- because the comparison work with material in external institutions is immense. Our systematics of the Peruvian Colostethus will be based on molecular genetic data- otherwise it will be too erroneous. Not all the frogs presented in Vol. 2 are APOSEMATIC ones- most Peruvian Dendrobates and especially the Epipedobates species are cryptics! See for example the ground living variants of D. fantasticus, which are hardly visible on the leaf litter.
"Belletristic" writing style is true- "belle" because of the beauty of the Peruvian species, our outstanding landscapes and fantastic habitats (see for example the D. mysteriosus rescue manual) and "triste" because of the Ecodestruction we suffer here, especially in High Forest, where most Epipedobates live. But jokes apart - the writing style is the liberty of the author.

PROJECTS:
We just finished the reevaluation of the situation of Dendrobates mysteriosus in the Cordillera del Condor after 11 years (INFORME DE CAMPO 01-2000 INIBICO-INRENA). What we found was a nightmare, not only because three German contrabandistas came in a few weeks earlier with my Boletín de Lima publication (Schulte, R.1990: Redescubrimiento y redefinción de Dendrobates mysteriosus MYERS 1982 de la Cordillera del Condor, Peru) to steal 40 or 200 of this severely endangered species! Those guys with the name Karl, Michael and Georg are offering those frogs at the moment in Germany- showing ONCE AGAIN, THAT ALL INTERNATIONAL CITES RULES AND CONTROLS ARE A BAD JOKE. INRENA and we try to catch them now. It is unbelievable- we are moving all contacts to get the Rescue reserve for D. mysteriosus financed (69.000 US $ for a two year and later self sustainable Project), when those Germans attacked and stole the frogs. WWF- Sweden first showed interest in the RESCUE Project- then they changed personnel and later they rejected it. So we had to look for a new Sponsor to finance this important project and got a new proposal. By luck- we avoided the huge administrative Project Overhead costs, typical for the WWF and similar institutions!

 

Only this year, thousands of Poison Dart frogs had been captured at international airports (Bogota 3000, Frankfurt 600), the German controls escaped a big shipment of 250- 300 yellow D. galactonotus from Brazil, sold completely on the black market like another shipment of red D. tinctorius. The one at Bogota had a market value of NEARLY A MILLION US $- and we must fight to get 69.000 US$ for a Rescue Reserve together? What is going on? Are we out of focus and CITES, too? The same German caught at Bogota was active long years in Peru, too, until we tracked down his method of getting the frogs out (there was a hole in customs) and informed the authorities.

Another INIBICO project in progress is a GEF- MSP to promote the new Dendrobatid management methods of the INIBICO in Peru and neighbouring countries, using a campesino- native community based production structure for JUVENILE frogs (this must be established as a new CITES RULE- no longer ADULT FROGS of Listing 2 species MUST BE SHIPPED AROUND THE WORLD- ONLY JUVENILES OR SEMIADULTS. This avoids the impact of FAKE projects depredating wild living reproductors at the moment in Centro- America and other countries.

Another new aspect of this project is to COMPLEMENT perfectly the IUCN- CITES strategies with an in situ protection of the last ORIGINAL HABITATS of the PDF all over South and Central America- the only way to avoid their extinction in the future.
The new methods allow to produce nontoxic and toxic frogs for scientific research and add a monetary value to standing rainforest- inducing the protection of forest rests and still standing rainforests by means of the former destructors! But the best result of the methods is, that the original reproductors and their natural offsprings are 100% protected- which is the PRIMARY genetic resource of the countries of origin!

The author presented the new management methods at the Seminario Internacional "Conservación y Biodiversidad: Reto para el nuevo Milenio" hold from 21.6- 24.6. 2000 at LIMA, Peru, and planned is another exposition at the International Frog Day (IAD) at Baltimore, USA.

INIBICO and the author thanks for the support from the Nordic Dendrobatid Research Group (NDRG) and the Swedish Herpetological Society, which published the Saving and Managing Dendrobatid Frogs in Original Rainforests article, traduced to their language. An English version is available free at inibico@terra.com.pe

 

Those are the latest news of our activities and technical data.

To contribute to the Saving of the Dendrobatids in captive installations, the author offers here the chapter 5.8 of Vol. 1 (Diseases) of the Poison Dart Frog Series: PERU- General Data, 400 pp, 150 photos, to be printed end of the year. Dr. Hugo Claessen, Belgium, and Dr. J.K. Frenkel, USA, revised this chapter and the author is very grateful for this help. It is thought to contribute to the better keeping of the PDF and represents a discussion base. Comments, propositions and experiences of other Dendrobatid keepers are welcome to include in Vol. 1.

 

Extract of manuscript of the book of Rainer Schulte:
Dendrobatid Frog Series: PERU: General Data Vol. 1, to be published end of 2000.
(Please cite the reference if you will use it in other publications).
Annotations in cursive and bigger letters maintained here are from Dr. Hugo Claessen, often followed by a statement of the author. This is to provide focal points of discussion.

5.8 DISEASES OF DENDROBATIDS

Like other animals, dendrobatids suffer from several diseases in the field and in terrarias. Meanwhile a parasitosis is often tolerated well in the field, the conditions of living in terraria can change this completely and the frogs may die. In nature, sick animals are eliminated fast by their enemies or insects (ants). Dendrobatid frogs have generally few enemies because of their skin toxins, but there are still some snakes, birds, ants or spiders that can attack and kill even a highly toxic Phyllobates.

 

In the authors first book (Schulte, R. 1980/1984) is mentioned, that every newly collected or purchased frog have to pass a strict and at minimum three months long quarantine in a well separated terraria in another room: everyone who did not accept this basic rule had to pay it in the past with financial losses and often with the death of unique reproductor groups and offsprings (which is worse than the loss of only a few dollars, which can be replaced easily- but one often never can find the replacement of the killed reproductor group, especially if it was a rare species from inaccessible places (D. azureus, D. tinctorius variants, D. steyermarki and others)! Everyone who enters the exciting world of dendrobatid management and breeding should keep this in mind and never forget! During this quarantine we observe the frogs closely, feed them excellently, make the preventive treatments against nematodes, other worms and against parasitic protozoa, check for chytrid infections, treat transport wounds and so on. This is a very important process and can avoid losses of several thousands of Dollars if we are managing a breeding farm or rescue project!

 

The presence of parasites like nematodes and other worms in the body cavity, tissues, lungs, eye or the intestine is common in amphibians, but with a dramatic increase in African frog species! From neotropical dendrobatids exist a few records in Silverstone (1975/1976) and observations from the authors labs. Such parasites are easy to kill with baths of Concurat, Panacur (Bayer) or similar vermicides (see Schulte 1980/1984, pp. 80-90 and the tables in this chapter). Especially during management projects we have to take care of such infections and revise our installations to avoid a massive contamination with such nematodes. If a lungworm infection is suspected, then the medicine Ripercol (Levamisole) may help as Hugo Claessen recommends. See treatment table in this chapter.

 

In the field, we sometimes noted amputated legs or arms with an incomplete regeneration process (D. imitator, D. variabilis, Colostethus spec.) and it is a normal observation during dendrobatid imports, that always a few animals show this problem- some may have suffered even from a smashing between the cover and wall of the container at the moment of closing the boxes! In no case, the regeneration process is so perfect and fast as we can observe it in European newts of the genus Triturus! Such limb losses occur in the field, when inexperienced enemies try to catch a dendrobatid or during such transport accidents. With luck, such a limb loss can heal but in most cases observed by the author and in the two labs, such frogs died, because the secondary infections advanced and intoxicated the rest of the body. In the field, such wounds may cure perhaps better.

 

There are no records of hand/feet regeneration by frogs. This exists only in newts. Check this out for dendrobatidae (H.C.).
Ok, those are our field observations mentioned above. From our lab during taking genetic samples by cutting 1/3 of the tadpole tail away in Dendrobates and Epipedobates, this cutted tail part was REPLACED first with strange WHITE tissue and later the melanophores built up and changed the color of the new tail to the usual black or grey. Peter Soegaard, Denmark, in his MSc. thesis about D. histrionicus mentions, that clipped toes of those frogs regenerated with the time, so he had to use an additional photo marking of the frogs! Our findings are therefore correct and we will take photos of such cases! (R.S.).

 

At San Ignacio and some places in San Martin, there live some new big semiaquatic Colostethus species together with the big dark red Amazonian sweetwater crabs (Pseudotelphusa aequatorialis: Potamonidae) in the earth banks of small quebradas: the frogs use the crab holes in the quebrada banks for egg deposition places and hide there during a disturbance. But the Colostethus population studied by the author at San Ignacio (Cordillera Occidental) (palmatus- group?) had some 30 - 40 % of frogs with amputated legs or arms! This indicates that the crabs perhaps FEED on such frogs or they get in combat if a frog enters in emergency a crab hole with the crab still in it! It is strange to see such a lot of mutilated Colostethus hopping around! Such amputated arms or legs we never could observe in E. trivittatus, E. bassleri and E. silverstonei, where the toxins seem to work more potent and defend the frogs! Colostethus frogs are usually considered nontoxic- but this is not true: C. inguinalis secrets a water-soluble toxin and the salmon red striped C. nexipus from the Cordillera Oriental with black tadpoles has a strong "toxin" if checked with the dangerous tongue test and which is possibly similar to the toxin of Epipedobates tricolor. But see also the following lines:

 

Hens killed and fed on Epipedobates bassleri and E. trivittatus in our backyard at Tarapoto and the same observation we made at the Cordillera Azul on E. silverstonei in 1979. Schlüter (1984, p. 206) mentions another accident with chickens and killings of E. femoralis and E. hahneli. How hens can feed on toxic frogs? Well, they grab the frog on one leg and throw the body against hard surfaces until the skin opens. Soon other hens are coming and try to steal the prey from the first hen. During this fights the skin is torn off completely and the hens can feed on the nontoxic carcass of the frog! Hens are possibly recent invaders in neotropical rainforests, brought in by the Spanish conquerors or perhaps living in the forest since several hundred years in the camps of the native tribes- although such tribes use generally domesticated forest birds and mammals instead of hens. It should be tested, if such domesticated rainforest bird species like the ones of the genus Tinamon, the Guans Penelope, and others can feed in the same way on syntopic Epipedobates or Dendrobates- at least they have color vision and the warning colors and toxins of the frogs may function in this predator-prey model. During one of our next travels to native tribes and virgin rainforests we will check this matter. Since the precursors of the dendrobatid frogs lived on the ancient Gondwana landmass, birds had been there, too.

 

In the Cordillera del Condor the author once saw a big syntopic bromeliad-living venenous ctenid spider bite a big Dendrobates mysteriosus, the frog showed the effects of the spiders toxin and staggered around, but could recover after a short time. This luck did not have a D. castaneoticus, which was attacked and killed by another ctenid spider as mentioned in Caldwell & Myers 1990, based on observations of Caldwell & Vitt- see also chapter Toxins. More observations on such and other terrestrial and phytotelmata predators are included in Caldwell & Araujo 1998. The author recently was witness of an attack of a tiny spider on an Adenomera frog at the Tahuayo- river: we were looking for some frogs in a palm base and two frogs jumped out- and adult Adenomera spec. and one semiadult. There was a movement on the leaf litter- and a tiny wolf spider of the same size as the juvenile frog jumped at him and bit him in the throat. The frog stretched the hind legs in three cramps and died instantly- then the spider tried to tow this heavy prey away over the leaf litter. This situation was sketched and drawn by the famous nature-aquarellist Lucía deLeiris, who was also present at the site this day. This show, that the danger of spiders to rainforest amphibians is widely underestimated and spider toxins seem to act instantly on amphibians or may kill them in parts of a second! The author recommends urgent research on those topics!

 

Absolutely new is a possibly host-specific color fly parasitism with fly maggots, also called myasis and known only from the Cordillera Oriental, San Martín (Peru), which affects the big epipedobatids E. trivittatus and E. bassleri. Not yet identified colorflies of the Lucilia (?)- group are causing this problem, which can kill the infected frogs. INIBICO is working on the determination of this color fly species. Strange is, that other regions of Peru have no problems with such a dendrobatid- Myasis.

 

In Europe is this also true. The fly (that infest the eggs and sometimes the sick frogs are from the genus Megaselia. We investigate this fly recently, the fly is probably Megaselia tropicalis, very common in the world.(H.C.).

This myasis is difficult to detect in early stages: During our combined field investigation with the KU- Group of Bill Duellman we collected some 20 E. trivittatus near the Chumilla river rapids of the Huallaga and we became aware of the problem only, when suddenly a lot of fly maggots crept around in the formaline fixation pan! Making a closer inspection, we saw the larvae coming out of a small hole in the dorsal skin of the big Epipedobates! Another case happened during the first part of the long time field investigation: the author saw an adult E. trivittatus sitting in a small artificial quebrada at km 6, road to Yurimaguas and coming closer, the frog made no attempts to jump away and was easy to pick up. Once in the hand, the author noted a 3 mm hole in the dorsal skin, interrupting one of the green dorsolateral stripes. In the hole, there was movement and the author decided to preserve this frog: 30 big fly maggots came out of the hole! The size of the maggots is the same as the ones sold in Angler shops as bait in Germany. Another case happened a few months ago, when we detected one semiadult E. trivittatus sitting in the water of a concrete quebrada passage (badén) where our jeep had to pass. The frog did not escape and showed problems to move one arm. Picked up, the frog was completely lethargic and did not respond. We put it back into the shallow water and when we returned after 30 Min, the frog was dead. The author decided to preserve it and once in the fixative solution, fly maggots moved around in a small hole in the dorsal skin above the arm insertion. A photo was made and the following dissection showed 19 fly maggots in and around the muscles of the arm insertion and part of the jaw musculature. The intestine and stomach was heavily filled with a strange white (purulent) mass and the intestine contained two nematodes. All this material is preserved, but we need to rear one infected frog until the fly larvae finish their development and the original adult flies may be visible! The problem is that all our samples died or had been preserved before making this test. In 2000, we will work especially on this problem to determine the fly, because this may be important for future management projects and for evolutionary investigations: specific parasite-host models require development-time and such periods are better available in a "Center of Origin" of a species than in peripheral, younger populations! Every time, when a big Epipedobates has no flight reaction and sits in water, a Myasis disease may be present! No treatment is known and there are perhaps some specialists who made similar observations or have an idea how to cure or avoid this myasis? This disease is restricted to the Cordillera Oriental range and was not present in other regions of Peru until now!
If the fly enters an unprotected ZIR-management project, there can be considerable commercial losses! But we can use fine- mesh screens over the juvenile frog terrarias and keep the fly away. We have to be very careful, not to take infected adult or semiadult Epipedobates from the Cordillera Oriental region to other places of Peru, or we may spread the disease to other forest ranges!

 

There are more evidences of strange diseases possibly caused by unicellular organisms (flagellates) or even worms, which fall in the difficult group of BLOATING DISEASES (Blähsucht). One example is the Case No. 2 in Van Rossum 1990, p. 87, where frogs slowly are swelling up until they are so round that they hardly can walk and will die soon. This type of disease can be cured with FLAGYL if flagellates are involved- see table in this chapter. Against mass infections with worms, which may cause a similar swelling and the difficult to cure lungworms is recommended the medicine RIPERCOL (= Tetramisol), which should be prepared especially (see Claessen, H. 1988). The doses and type of treatment see the table at the end of this chapter.

Another very dangerous version of the Bloating Disease complex is the one introduced with Dendrobates reticulatus from the Iquitos region of Peru- and this happened even to the author! This disease is highly contaminating and usually all frogs of an infected shipment die- even the few ones collected personally at Iquitos and transported with the greatest care and experience picked up this disease and infected other species in the same box. This problem is transmitted by D. reticulatus! The diagnosis is a fast swelling of the body and to a lesser degree of the limbs. The frogs may survive a few days but die finally if no treatment starts! It is still to check, if the faster acting bloating disease observed in E. pongoensis is of similar origin! To check if a frog acquired this disease we have to look at the gular area: if the throat is inflated or swollen, the frog has the disease- if the area is flat and normal, the frog is a ripe female full of eggs! The author had success with a treatment, but the frog may stay contagious- so it is necessary to discard all terraria interior and desinfect it with powerful solutions and rinse well after finishing the desinfection: some disinfectants are highly toxic in traces like phenol or ammonium based liquids. The author used in Germany Formaline based solutions in 1981 (FORMAVETYL). Frogs which had once this disease never should be mixed with other, sane frogs and get a terraria of their own. All dendrobatid keepers should therefore act with caution if purchasing wild caught frogs from the Iquitos region. INIBICO made a project to investigate this dangerous disease and its origin and way of contamination, but we could not get on the funding. For this project we need a good photomicroscope with high magnification to check which bacteria or agent causes this disease (we have only a dissecting microscope, which is not useful in this case). The present disease is very dangerous, because the wild caught Iquitos frogs may infect all the installations of the intermediate commerciants and later the terrarias of the hobbyists! Previous the opening of the frontier for the export of wild caught frogs, such problems should be resolved first! Our recommendation is, that the export of such frogs has to be stopped immediately because it is a danger to other countries which may receive such frogs (veterinary import laws!) and in every case such shipments need to enter a quarantine of two or better four weeks according to our own experience with this disease. Several Peruvian commerciants lost all frogs in the past, even on such short flights from Iquitos to Lima! The reason of the outbreak of this problem is not clear: the author suspects, that the jet flights (air decompression and compression) may start this disease- but even such frogs shipped in fish boxes with oxygen showed the problem! INIBICO will start urgent investigations on this disease, because it may affect our Zoocriadero produced frogs in the same way, if working with such projects in the Iquitos region and this is not acceptable in our future enterprises! Such sell and run- business is not our style and our produced frogs have to pass the most exigent quality controls in the future. Therefore we currently avoid bringing adult D. reticulatus to Tarapoto and when, we use only eggs and tadpoles and raise them in the lab- this avoids problems in our installations. The author could control this disease, but treatment lasts at minimum 12 days - 2 weeks until the frogs return to normal outlines, but may maintain possibly the transmitter status! We would like to contact some specialists, which can help us to detect the cause of this particular type of BLOATING DISEASE. Other frogs from other areas across the Amazon and Ucayali showed no problems until now, if not mixed with Iquitos frogs! It seems, that the carrier of this problem is only D. reticulatus, but other frogs can get infected if coming in contact with this species (we had problems with reticulatus-infected D. amazonicus and D. variabilis!). The author recommends to all hobbyists and professionals to make a strict quarantine if purchasing frogs from the Iquitos area until we could finish the investigation and discover a secure treatment!

A broad spectrum of bacterial diseases, often caused by Pseudomonas-species, can attack dendrobatids, especially if their skin has wounds caused by a wrong catching method, by badly designed transport-boxes, or by a wrong keeping or feeding. One of the diseases which automatically can be observed after getting open wounds is the Leprosy-like dissolution of skin, muscles and bones, called "Lochkrankheit" or "Knochenfrass" in German, which may be possibly equal to gangrene? As a first introduction to this dendrobatid disease see Schulte, R. 1980b and 1980/1984,pp. 82 ff. The "Knochenfrass" was a severe problem in the 80-ies, but we can cure it today with antibiotics (Sulfonamides and other medicaments), which are applied externally and internally via the food insects. It is absolutely a must during dendrobatid handling and keeping to avoid all wounds of the frogs (see those open heads, open snouts and deep scratches on the dorsum or even amputated legs due to accidents in the transport boxes). Every dendrobatid with such wounds will surely cause problems and if not treated, this frog may infect other frogs in the same cage and finally, all may die within a few weeks! Every ill frog in a cage or transport box is a time bomb- therefore we keep them isolated in special terrarias and rooms!
The author recommends to examine well all freshly collected frogs or purchased ones with a magnifying lens: looking along the dorsum, the limbs, fingers and toes, and especially the head and nose area: one may note perhaps fine wounds like whitish or grey punctures- such are the starting points of the "Knochenfrass"- disease! If such a disease is observed in one terraria, all interiors must be disinfected with powerful agents and later well rinsed before returning the frogs. The old decoration or plants have to be discarded and burned!

Fungi may be present as secondary infections of wounds and there exists today several ways to treat them with highly adhesive antimycotical creams (but see the Chytrids!).

 

Another problem commonly observed during dendrobatid keeping and breeding (even in our field management project) is the DROWNING of frogs in the water containers of their terrarias or even in one case in one of our artificial phytotelmata (COCO- containers) on the summit of the Cordillera Oriental.

All drowning may be related to slippery side walls of the cages, lacking drowning protectors, an incomplete skin shedding process, and diseases (see the Chytrid infections!). Therefore we have to take a closer look and a dissection of the drowned frogs is necessary- maybe we can detect a dangerous disease in the early stage of infecting our entire cage. Slippery side walls in terrarias and outdoor structures like our artificial phytotelmata are caused by slimy algae growth and frogs often desperately try to get out of the water but slide back again and again. As mentioned in the Barrier- chapter, dendrobatids are no good swimmers and may enter in stress and drown after a few minutes! During our management pilot project, we first forgot the drowning protector structures and on the base of drowned insects and Eleutherodactylus frogs we use currently cutted and folded palm leaves in each artificial phytotelmata (after bad experiences with other softer leaves!). Using such drowning protectors, we have no problems any more with drowned insects or frogs and even the reproduction increased considerably, because the frogs like to put eggs in a little protected places- and the folded palm leaf resulted a fantastic addition to our artificial phytotelmata, improving even tadpole survival: we can get now often two or three tads from one container, because the leaf avoids sight contact among the tadpoles and the swim fights! (Details see the INIBICO- Dendrobatid Management Manual No. 1).

In our terrarias, it is always necessary to provide such drowning protectors if we use open water containers in the cages: some branches of water plants, a small Styrofoam island, inclined side walls of the water container are good strategies to avoid the losses of frogs! In our new cage design, we changed from the "open water container type" to the "short quebrada type", but with some ditches in the artificial quebrada, in case that there is a failure of electric energy or of the powerhead pumps (a common fact at Tarapoto), so the frogs may not sit in the dry, especially if we are out on field work or expeditions a few days!
Ill frogs always seek water and return to it- this is a basic observation during decades of frog breeding! Even the deadly chytrid infection had been discovered first on dead frogs sitting in the quebradas or ditches in Costa Rica, Panama and Nicaragua! If you see a dendrobatid frog (which is not a semiaquatic Colostethus!) sitting longer times in shallow water- there is a disease coming up and one has to observe well the terraria during the next hours and days! Once, the author observed a strange behaviour in one of our artificial phytotelmata (COCO) on the summit of the CO: during one of the census of the COCOs, we detected a D. variabilis HEAD DOWN in the water of the vessel, which made no attempts to come up and breathe! It is normal, that our reproductors jump into the COCO vessels and hide there a moment if we are coming to inspect their place, but this frog made NO ATTEMPT to get his nose up and breathe. So I collected the frog and having a closer look, the animal showed a big tumor above the arm insertion at one body side! It seemed that the frog was just making a perfect suicide by drowning itself in the artificial phytotelmata! I put it back on the sidewall of the vessel, but the frog again jumped into the water with the strange position of the head down and staying there again. We do not like dead frogs in our containers, so I took it out and put it on the forest floor (our project is located in a strictly protected rainforest and we AVOID collecting or disturbing the animals living there- even ill frogs!). Revising the COCO- containers during the next census, there was no trace of this ill frog.
With a good design of our terrarias and our management structures, we can avoid the drowning of our frogs, but in every case such a problem is observed, we have to check for a disease!

This is without doubt the longest chapter of this book but the most important one, too, and what is coming now on the following pages, are the WORST DISEASES AND DEVELOPMENT PROBLEMS EVER OBSERVED IN AMPHIBIANS:

One of the most dangerous diseases ever discovered in dendrobatids (apart of the chytrids) are virus- infections with a new type of virus, detected recently for the first time by Dr. J.K. Frenkel, Sta. Fe, USA, in samples of D. granuliferus from Costa Rica, which suffered from the famous "Scratching Disease= Kratzseuche". Dr. Frenkel wrote to me, that the new virus belongs to the Pico- RNA- group and more investigation on the matter is very urgent (the microphoto shown in this book is a courtesy of Dr.J.K. Frenkel, Santa Fe, USA).
This virus group can cause a 100% mortality in frog farms, terrarias and perhaps in the field. The countries from where we reported this disease so far are Costa Rica (D. granuliferus) and French Guyana (D. tinctorius). The virus may be transmitted by food (fruit flies) from one terraria to another and there exist the observation made by Rolf Bechter, Zürich, Switzerland, that the disease probably is constantly present in the habitats (and bodies?) of the frogs and cause problems only when kept in terrarias. Another unconfirmed version is, that the disease attacks only under very humid conditions (rainy season). The fact is, that this or a similar virus was responsible for the killing of unique breeding groups and the world's first captive reared froglets of D. histrionicus, D. lehmanni and D. pumilio, obtained by Rolf Bechter with the pioneer method of feeding egg-yolk, which was discovered by him in 1977 (Bechter, 1978).
The attempts to cure this mortal and extremely contagious disease with antibiotics and Chloramphenicol showed only sporadic success, often resulting in a permanent damage of the frogs (see Heselhaus 1984, p.43). Newest data of Heselhaus (1988) indicate, that a cure perhaps is possible, using a medicine against human ear-infections (Panotile, Inpharzam GMBH, Germany) and which is applied as drops on the dorsum of the infected frogs over a few days.

 

It is interesting to give the name of the medication, but also the name of the active component, because the medication has different names in different countries. (H.C.). The author tried to get on the active agent name- but this was not possible. Perhaps some of the readers can help here, giving us the name of this active component? (R.S.)

 

Another method may be tested, too, with human eye-medicines used for conjuntivitis-infections, the author). But apparently cured and sane frogs may remain transmitters! According to Dr. J.K. Frenkel, there is hardly any medication to kill a virus!

 

There are now a few products acting against viruses.

Dideoxyadenosine against Retro-virus
Zovirax (Acyclovir) against Herpes-virus
Cytovene (Gancidovir) against Cytomegalo-virus
Imuniriral (Inosine Pranobex) against Epstein-Barr-virus
Viroptic (Trifluridine) against Ophtalmic-virus (this perhaps was in Panotile?)
Retrovir (Zidovudine) against Retro-virus
(H.C.)
This virus should be investigated urgently, because it may produce severe impacts in local faunas and commercial farming projects and even the rescue of species can be completely hindered. Terrarium hobbyists are recommended NOT TO KEEP WILD CAUGHT FROGS of the critical species and better use the captive bred offsprings, available in high numbers and excellent quality from breeders in Europe. The introduction of such new viruses may KILL ALL FROGS in all cages of one hobbyist or a breeding farm! Breeders which work with such wild caught species should take all the necessary preventions possible: Nearly sealed quarantine terrarias in a sealed special room in another building, food supplies and cultures far away from the cages of wild caught frogs, constant and minimum observation time of 6 months, constant desinfection of the equipment and tools used to service the terrarias and so on. Several professional dendrobatid breeders had VERY BAD experiences in the past- so care and caution is the best method!

 

The next severe problem is probably a complex of several pathogens: the mass-dying of D. histrionicus exported from Colombia: In the 80- ies and later, big shipments of several variants of D. histrionicus reached the USA and Europe, but nearly all frogs died within a few weeks- and this happened even to the author several times. The situation was terrible and we were unable to get on healthy frogs! During such an event in 1981, the author sent some beautiful but dead frogs of his last purchase to the office of Dr. Reichenbach Klinke- the famous German specialist of amphibian diseases at the University of Munich- Institute of Hydrobiology and the result of this analysis is stored in our INIBICO files now: a multiple infection of the intestine and the liver in all checked samples!

This infection had been picked up without doubt in the installations of the collectors and intermediate dealers at Cali, Colombia and other sites, where such frogs had been handled and sold. A few D. histrionicus variants brought to Europe, directly caught in original rainforests by several terrarium hobbyists, survived without major problems, but their tricky reproduction with feeding eggs is until today a major challenge! The only persons who had excellent and constant keeping and reproduction success with those frogs (with Rolf Bechters yolk-feeding method) seem to be the Zimmermann- group at Stuttgart (Zimmermann & Z. 1980, 1981, 1982). But it should be checked, if the parents came from the frog commerce or from direct hobbyist-collectors! D. histrionicus-group frogs need generally a very high air humidity, the Chocó- Pacific rainforests may have 5000 mm or more precipitation per year- one of the highest values of the South American continent and recorded so far only from the Venezuelan Andes, some ridges of the Cordillera del Condor and some oriental front ranges of the Southern Andes in Peru!

Before opening the frontiers for such shipments with infected wild caught or Zoocriadero-frogs from Colombia, we urgently have to check what happened in this country and where the frogs became contaminated and we have to detect the bacterias (or viruses) which caused such problems not resolved until today! The two Colombian volumes of the authors PDF- book series will be the LAST ONES, because it is very easy to get killed during the investigation of strange frogs in this country and the author prefers to live with venenous snakes in the forest than to step on nacroterrorist base camps or guerrilleros! But we will have a short look to some southern Pacific rainforest species when investigating the Ecuadorian frogs. The Colombian dendrobatid fauna perhaps should be treated in one Volume for the Pacific Rainforest species and another for the Amazonian species.

 

There is another strange disease or better development problem, which affects severely the terraria frog offsprings in the USA and Europe: The Spindly Leg Syndrome (SLD) is responsible for the partial or complete loss of the reproduced froglets. This disease never was detected in the INIBICO- Lab or the field in Peru, but the author had bad experiences in the Neuhausen Lab with wild caught breeding groups of D. auratus/ D. tinctorius and at least one spindly leg froglet from an original bromeliad in Ecuador has been discovered recently by Harald Divossen.

 

The Spindle Leg Syndrome (SLD) is a multiple factor problem and the first publication about this very strange disease of dendrobatid froglets was the paper of the author (Schulte 1980 b), combined with a questionnaire distributed among European dendrobatid keepers with one issue of the herpetofauna journal in 1981. The beginning of the first laboratory-, light- microscopic-, and X- ray analysis of D. auratus samples provided by the author started in 1981. An improved version of the questionnaire sent in 1981 to the dendrobatid keepers and breeders in Europe is added here in the Appendix chapter and all persons which observed such a disease should order this form via Email and send it back to the INIBICO to try to resolve this problem urgently.

The institution in charge of the tissue and sample analysis of the SLD was the Institute for Hydrobiology und Limnology of the University of Munich, Germany, and investigation was conduced again by the famous amphibian disease specialist Prof. Dr. Reichenbach-Klinke (see his book: Krankeiten der Amphibien, 1961). Samples of D. auratus froglets were provided from the author's lab at Neuhausen, Stuttgart.
Unfortunately, the author had to leave for Peru in 1981 to start a longer field investigation (dissertation project) and circumstances stopped the investigation of this and other important facts about frog reproduction, calls, behaviour and diseases.
Now, nearly 20 years passed, and the Spindly Leg Syndrome still exist and causes the same losses. The experiences of the past decade, published in a lot of articles in aquarium and terrarium magazines in Europe (Heselhaus 1983,1984,1988 and others) showed, that the problem is caused by several independent factors and its real origin is very difficult to define. Meanwhile some hobbyists found the solution of the problem, others failed completely with the same treatment!

Why is the Spindly Leg Syndrome so important? The offspring output of any captive managed dendrobatid can fall to ZERO, and this level can be maintained over longer periods and some breeding groups never recovered normal fertility and juvenile frog survival rates! The example of E. tricolor presented in Heselhaus (1988, p.84) show, that from a total production of 139 eggs during 7 reproductive events in three months NO SANE FROGLETS COULD BE OBTAINED! If estimated on an annual production of 600 eggs from one pair of Ecuadorian E. tricolor, the TOTAL LOSS OF THE WHOLE OFFSPRING is a complete disaster!

The endangering of a lot of dendrobatid species in always smaller forest rests, the menace of altitude amphibian extermination caused by hard UV-B radiation, the chytrid- killer-fungi holocaust and other man-made effects require the planning and starting of the first urgent Dendrobatid Rescue Programs in the next months (f. ex. of D. mysteriosus in tiny forest remnants in Peru or of D. lehmanni in Colombia). Our three stage- dendrobatid rescue method was designed on the base of long years of experience with such frogs: The first rescue step includes a laboratory breeding program of the endangered species to obtain a maximum output of juvenile frogs for repopulation in strictly protected areas and for detailed investigation. If this laboratory phase fails because of the spindly leg problem, the whole project is endangered, because natural reproduction of an endangered species is too slow because of low survival rates in the field- and this is valid even for toxic frogs like the dendrobatids!

The nearly complete forest destruction in the habitat of D. mysteriosus for example occurred recently during the past 40 or 60 years! This is absolutely too fast for any species living in such minute forest rests, which are cutted down daily for firewood supply of a triplicating human population and the need for pasture land for cattle farming. Therefore it is important to prevent such project failures and it is necessary to be able to control the reproduction process in a perfect way.
The existence of a specific disease which can eliminate all offsprings during the intensive type of management is a tremendous future menace for laboratory rescue breeding and we should combine all efforts to investigate and to dominate such diseases. This volume still cannot provide solutions to overcome the problem of the Spindly Leg Syndrome, because each observed case is completely different, like the factors which can provoke this disease, but the author tries to give an overview and to discuss facts from amphibian embryonic development, from lab investigations of affected froglets, from possible treatments, and how to direct future investigation of this dangerous syndrome, facilitating perhaps future emergency-breeding projects.

Newest data from Europe (Resumed by Hugo Claessen, Antwerp, Belgium in BDG- Newsletter, data from Dr. Thomas Wöhrmann, University of Aachen, Germany and Gouda & Hak 1995, University of Utrecht) show that the Spindly Leg Syndrome can be triggered by a gene failure. This gene controlling the formation of the forelegs is called Homöobox XLHBox 1 and the Spindly Leg Syndrome could be artificially switched on, placing a disruptor into this gene segment. Which agent or which factor may trigger the disruption of this gene segment and posterior malformation of the forelegs is still unknown. High subnormal temperatures, hard radiation or free radicals might trigger this effect, perhaps directly in the eggs during the first development stages or may even come from the parents. Most interesting is, that the same gene XLHBox 1 is also responsible for a strange human baby malformation, called Spina bifida (Babies are born without a completely closed spinal column)! Preventive treatment in humans is to give large doses of Folic Acid and Vitamine E to the mother- and Hugo Claessen stated that we should try such a treatment in the reproductor frogs. Dosification and other details are completely unknown- but first experiments should be started with the adult frogs, which produce spindly leg offsprings. It may be that the syndrome is switched on at the egg stage and future experiments must show the way, how to avoid this fatal disease. But there are other failures possible and in the author's opinion, the Spindly leg syndrome is in EVERY CASE a Multifactor caused disease- see below:

 

The following summary describes the Spindly Leg Syndrome, which attacks primarily froglets of nearly all genera of the family of Poison Dart Frogs (Dendrobates, Colostethus and Epipedobates), and some newest informations confirm the same problem for Hylid tadpoles, but is restricted currently to the management of captive frogs in Europe and USA and not recorded from Peru or our lab (but see one record from the field in Ecuador).

A common advanced-stage tadpole development is described here to get an idea where the problems may be located:

During the last stage of larval development, the front legs are formed from cell groups (buds) within the peribranchial pockets. The growing arms stay there, until the final resorption of the tadpole's tail begins. Then, the arms break through a window in the peribranchial- and gill-compartment and the froglet finally has four functional limbs, which allow a terrestrial or semiaquatic life style.
When suffering from the Spindly Leg Syndrome (SLD), this is quite different:
The arms are build from the buds, but the growth of the arm bones, articulations, tissues, and perhaps other structures like blood vessels or nerves is completely altered (see photos in Schulte 1980, Heselhaus, 1984, p.43, 45; 1988, p.87). The resulting arms are extremely thin and sometimes bent, articulations often rigid (elbow and shoulder), and arms can break through the gill compartment or not.
The survival of the froglets, which show always a sane resting skeleton and completely normal and powerful hind legs, is ZERO because the arms cannot be used for climbing, creeping or swimming, and foraging of the froglet is impossible. Death comes by starving or drowning.
First light- microscopic and x-ray analysis made in 1981 in Munich showed a complete atrophy of arm bones and tissues (the author has the results and x-ray films at Tarapoto), but the travel to Peru stopped the investigations. The following steps had been planned to continue with this investigation:

1) Staining of microtome thin film cuts for light microscopy (the tissues, bone and cartilage structures) with specific histological stains (Haematoxylin and others). This phase was conducted recently by Dr. Thomas Wöhrmann, University of Aachen, Germany.

2) Check, if nerves, muscles and blood vessels are also affected.

3) Transverse microtome thin film cuts across the arm insertion section of the body and specific stain for cartilage and bone structures.

4) Electron microscopy of thin film cuts and analysis from arm section and arm insertion section, looking for alterations at cell and bone structure basis.

5) All tests and cuts have to be done with Spindly Leg- specimens and healthy test frogs to be able to detect the differences!

 

There are at least six hypotheses about the origin of this syndrome:

1) The syndrome is started by toxic agents (pesticide traces, toxic metal ion traces, microtraces of toxic substances emitted from plastic material- H. Claessen, Email. com.) in the water or provided via the food (valid for eggs, larvae and adult reproductors!).

2) The disease is a common deficiency of vitaminerals and micronutritients, caused perhaps by excessive biofiltering!

3) The syndrome is a common "RICKETS", started by the lack of calcium combined with a vitamine D deficiency (Dr. Jaeger, Aquarienmagazin No. 5, 1986).

4) This syndrome is a genetic deficiency, caused by excessive interbreeding with close relatives (Inzucht, Heselhaus 1983, 1984, Schmidt 1985). At least one genetic failure could be confirmed now by yet unpublished results of the working group of the University of Aachen- Dr. Wöhrmann). Disruption of the Homöobox Gene XLH-Box switches the SLD on- the same disruption of the same gene in humans is responsible for the Spina bifida Syndrome! Which agents may trigger this disruptor switch is still unknown.

5) The SLD is triggered because of iodine deficiency, affecting hormone production of the Thyroid gland.

Personal I think there is no reason ever found that this is true. I believe that iodine has nothing to do with SLD. Dr. Wöhrmann, found that the thyroid gland was fully normal in SLD froglets.(H.C.) (My observation (R.S.) is, that iodine has really an effect on SLD- at least in some cases and tested by some famous PDF breeders (Dr. J.K. Frenkel, Sta. Fe and Charles Nishihira, Hawaii).

6) The "inflating of the egg-yolk" in early embryonic stages is the cause of the syndrome (Heselhaus, Schmidt).

7) An excessive high water and terraria temperature during egg and larval development may trigger the syndrome (J. Rademaker, Dendrobatidae Nederland, Vol. 7-12,p. 77, 1990: Dendrobates histrionicus confluens).

In the authors lab at Neuhausen, this disease appeared in freshly WILD CAUGHT D. auratus (Panama), D. tinctorius (French Guyana) and E. tricolor, meanwhile all the other frogs showed NO PROBLEMS- this included: C. nexipus (which is now severely affected in terrarias of other hobbyists), E. hahneli rubriventris, E. bassleri, E. femoralis, E. silverstonei, E. trivittatus and others. The authors tadpoles of D. auratus and D. tinctorius were kept IN PLASTIC TOOPER WARE with a biofilter system passing via a PLASTIC AQUARIUM! According to the personal experience of the author, the problem was NO GENETIC one, because the frogs had been recently caught in the original rainforests. The filter system (Eheim Suctionfilter and spray tubes) may have caused the trapping of micronutritients, but other tadpoles in the same water showed no problems. A "Rickets" could NOT be the origin, because all froglets came out of the water with a good size (10-12mm) and an excellent skeleton with completely normal and powerful hind legs, except those strange spindly thin arms! A "Rickets" should have caused generalized skeleton failures in the spinal cord and the hind legs- but this is NOT THE CASE in most observed froglets which show this disease: all have a normal skeleton and strong hind legs!

Several hobbyists started with their own experiments to detect or to stop this syndrome- some had success, but others failed. After receiving recently the information of the detection of a new highly toxic agent dissolved from some plastic materials (Hugo Claessen, Belgium) the author suspects now, that the plastic tooper compartments or the plastic aquarium of the Biofilter Unit was the possible cause of originating SLD in the Dendrobates tadpoles of the Neuhausen Lab, while Epipedobates tads maintained in glass aquariums showed mostly no problem! It may be, that the toxin triggered the disruptor of the XLH-Box gene in the early development stages of the egg! At least this can be the explication of the different results observed with different tadpoles. The author recommends therefore, to ban strictly all plastic materials in tadpole raising units or biofilters! Only glass and silicone sealant should be used! Plastic hoses which connect the filter and spray tubes may release toxins, too! The best will be here, to design a staircase water transport system and avoid plastic hoses whenever possible! Such designs are coming in the new replacement book of the authors first book "Frösche und Kröten- Ulmer Verlag, Stuttgart", which is long years out off print.

 

The metamorphosis of amphibians in all details is a process not completely investigated and understood until today. We know some few details, but biochemical und genetic timing of the tremendous changes going on in the body tissues and organs of any tadpole which goes on land are poorly understood. A short overview of the present knowledge gives Duellman & Trueb 1986 (and newer editions) in their excellent book about the Biology of Amphibians.

The author will resume here a short history of the changes going on in the tadpole body, combined with own comments and endocrinological data, so researchers perhaps can find starting points for own detailed investigations on the Spindly Leg Syndrome- which we MUST RESOLVE AS FAST AS POSSIBLE! But we have to accept, that the Spindly Leg Syndrome ONLY affects the arms, the elbow-, hand- and perhaps shoulder articulations- the rest of the froglet is NORMAL and very healthy! This disease starts obviously in the early stages and center phase of metamorphosis, not at the end!

 

After Etkin 1932, all processes of metamorphosis can be separated in three main periods: 1) the PREMETAMORPHOSIS, 2) the PROMETAMORPHOSIS and 3) the CLIMAX. The forming of the limbs (arms and legs) falls in the phases 2 and 3. Of special interest is here the function of the thyroid gland, which produce two very important hormones: the Thyroxine (T 4) and the Triiodinethyronine (T 3), if the supply with iodine over the food chain or the surrounding water is secured. If there is a lack of iodine, the production of the two hormones fails! The iodine from the food or water is stored as iodides in the body of the tadpole and the thyroid gland uses this stored iodide for the synthesis of the two hormones as the body will require those. The function of the thyroid hormones in general had been studied by Gundernatsch (1912) by means of feeding macerated thyroid glands from horses to tadpoles of the European Rana temporaria, which started after such a treatment with a very accelerated metamorphosis. On the other hand, the removing of the thyroid gland in amphibian tadpoles leads directly to NEOTENIC larvae, which never will finish a metamorphosis and will live as giant larvae for the rest of their life. It is to mention here, that the two hormones T 3 and T4 from the thyroid gland CAN ONLY FUNCTION, IF THE RECEPTORS FOR SUCH HORMONES IN THE TARGET TISSUES ARE READY- AND NOT OCCUPIED! (During the development of the Spindly Leg Syndrome, there may be a problem with such receptors: they may totally lack or are occupied or better blocked by another competing agent! -comment of the author!). During the metamorphosis, researchers found differences in the amount of FREE RECEPTORS among different frog species, facilitating the construction of species-specific tissues at a time they are needed. Summarized, the two hormones of the thyroid gland together with the receptors CAN PRODUCE A SPECIAL BODY TISSUE WHEN IT IS EXACTLY NEEDED! (And just here may be located the second problem - apart of the first: the lack of iodine in the food or water!).

The two thyroid hormones T3 and T4 reach their maximum concentration in the blood plasma during the second phase of the metamorphosis, called Prometamorphosis and are the direct responsibles for a whole series of changes, which are summarized in Tab. 7.2 in Duellman & Trueb 1986. Here are mentioned: the "construction of the skin" of the arms and legs, the opening of the window or foramen to facilitate the breakthrough of the arms across the walls of the peribranchial pockets, the growth of the leg muscles, and the resorption of the tail- accompanied by more than 28 (!) other functions and changes. But here comes another observation: to steer this high number of changes, the T3 and T4 hormones need an antagonist to regulate them (some kind of biochemical emergency brake if something goes wrong) which could be detected in amphibians as the hormone PROLACTIN, produced in a tiny gland called Adenohypophyse or anterior pituitary. Please remember here, that during and AFTER the breakthrough of the arms, the tadpole tail still has to be eliminated or resorbed as one of the last major changes in the body outlines! The Spindly Leg Syndrome can be analyzed here as the failure of the "skin construction" of the arms, often the Window fails and does not open, and arm muscles are "not constructed"!
To understand more processes of the Met (shorting used for Metamorphosis) we leave the thyroid- gland and need to overview other important functions of the tadpole's body:

Other important organs are the two Ultimobranchialbodies, which appear for the first time during the evolution in frogs and which are directly responsible for the hormonal steering of the Calcium- mineral-metabolism by means of the hormone CALCITONINE. The pair of parathyroid glands (the Ultimobranchialbodies) is ready to function in the tadpole's body since the early stage of phase 1, the PREMETAMORPHOSIS. The hormone Calcitonine is responsible for the ACCUMULATION AND STORING of CA2+ -ions into the tissues and bones!
Previously, calcium ions are extracted from the surrounding water and stored as the difficult to resolve mineral ARAGONITE (Calcium carbonate) in special endolymphatic pockets in the tadpole's body. At the beginning of the phase 3, the CLIMAX, we can detect an increased amount of free calcium ions in the blood, because the release of the mineral-storing hormone CALCITONINE (which we mentioned above as the product of the pair of the small Ultimobranchialbodies) is restricted by an antagonist (another biochemical emergency or regulator brake), which probably is the PROLACTIN in amphibians (mentioned above as the hormone of the small anterior pituitary). This leads immediately to the storing of the free calcium-ions into the bones to facilitate the following change to a terrestrial life of the juvenile froglet when the new skeleton has to support gravity and air pressure.
The amount of free calcium-ions in the blood is regulated in mammals by a minimum of two hormones, so that the levels constantly are maintained at 10 mg free calcium ions per 100 ml blood plasma. If this level increases (we eat a calcium mineral pill), Calcitonine will store the surplus mineral directly into the bones. If we have a lower level of free calcium in the blood, the PARATHORMONE (which is produced in the parathyroid glands of the thyroid gland) releases calcium ions instantly from our bones and let them flow in the blood stream. But there are more control systems in mammals present, which regulate the mineral metabolism. The parathyroid glands are lacking in fishes, but are present as special cell masses in the amphibian body and perhaps may produce the Parathormone or a similar antagonist.
The Parathormone is furthermore responsible in the body of mammals for the calcium-ion uptake from the intestine, but functions only in the presence of vitamine D 3! The Parathormone has another function as a calcium-ion-retainer in the kidneys, interchanging them with phosphate ions: there is in mammals a constant balance of phosphate and calcium ions present in the blood plasma and we can predict a similar fine tuned regulation-model in amphibians!

During the Met it is perhaps possible, that tadpoles with a vitamine D deficit and/or a deficit of calcium ions (all Aragonite reserves finished) may produce the syndrome, because the arms are the last bone structure to be built up, parallel to the resorption of the tail! This would explain the experiences of some hobbyists, that in a few cases a vitamineral feeding could terminate the syndrome. But this does not explain the atrophy of the muscle and other tissues and the complete stiffness of the articulations, which commonly accompany the Spindly Leg syndrome (see also the microscopic thin layer sectioning data and X- ray analysis stored in our files). Improved vitamineral feeding did not resolve the problems of the author in 1981 and other dendrobatid breeders! It is therefore postulated, that the syndrome is caused by a combination of factors or different causes, which may be vitamineral or iodine deficits, toxic substances blocking important receptors, failure of the genetic steering during the production of the tissues and ossified structures and some more. It may be, that the yolk swelling, possibly caused by bacterial infections, can produce the same syndrome as it may appear during long time interbreeding. The observed temperature effect of inducing the syndrome with higher temperatures in D. histrionicus confluens may be a biochemical steering failure. Tests with pesticides, toxic elements or heavy metal ions (Zn, Sn, Al, Pb, Cl and Cd) should bring some additional data. The author is sure, that the chemical industry and especially all big enterprises which produce pesticides have informations of test runs of agents against amphibian larvae and the author would like to get in contact with such persons, which could induce this disease in amphibian larvae in general! The author suspected in 1981, that some strange substances in our local drinking water supply in Germany caused this syndrome in delicate species, but hobbyists have some dozens and more theories about the cause of this disease.
The best test frogs for this syndrome are Epipedobates tricolor with a fast reproduction and an University should perhaps start an urgent thesis on this syndrome or go on with investigations! Hobbyists who have such reproductor groups, which produce only spindly leg-offsprings, should communicate immediately with the INIBICO to organize the investigations on this matter.
A comment of Dr. J.K. Frenkel (who revised the English text of this chapter) was, that he never observed the Spindly Leg Syndrome, if the tadpoles are kept in distilled (?) water with a drop of diluted iodine every month. The author wants to add here, that perhaps the term "boiled water" may be correct, because during distillation of water all necessary minerals are eliminated and may cause the syndrome because of mineral deposit deficiency!

In Germany and Holland they use now often reverse-osmose water, which is the same as distilled water. All minerals are removed.(H.C.).

If we want to use real "distilled water" or such one passed through molecular filters, we should provide the microelement and mineral additives the aquaculture enterprises offer for such cases. The author wants to get in contact with hobbyists who used such methods with or without success.
Breeders which have problems should read the Spindly Leg- Questionnaire in the Appendix and order via Email a form to fill out- the author and a lot of desperate dendrobatid breeders need to RESOLVE THIS PROBLEM FAST! It would be good to include this disease in one of the next international frog meetings and herpetological congresses! Every observation and discussion about this matter is very welcome and important!
Another observation from Dr. Frenkel is that in spite of vitamineral feeding, several of his frogs died with mild or severe rickets! This will mean, that there is perhaps a problem of vitamine or mineral uptake in captivity or in frogs in general! We apply minerals and vitamins by powdering them over the food insects and some hobbyists drop the vitamine solutions onto the dorsum of the frogs, but this strange observation of Dr. Frenkel indicates that there is possibly an activation failure of the vitamins or mineral metabolism in his frogs. The author recommended in his first book, that dendrobatids are semishadow- animals which often need SUNLIGHT in small doses- maybe that the amphibian body cannot process the vitamins designed for higher vertebrates or mammals? It is the best, to provide the basic materials AND applicate a slight UV-A radiation via mercury (HQL) lamps or special fluorescent tubes (Vita Lite and other brands). The author would like to discuss this matter with other Zoo- veterinarians and hobbyists to improve the keeping of frogs in the future.

Here comes now the new Chytridiomycosis- amphibian killer disease: Meanwhile the author was finishing the work on Vol. 2, PDF-PERU, strange notices from newspapers and scientific journal copies came from Dr. J.K. Frenkel, Sta. Fe. in 1998 to Tarapoto: fastest amphibian exterminations occurred in such famous places like the Las Tablas Province, Costa Rica, the Fortuna Reserve in Panama (see Karen Lips, Conservation Biology, Vol. 12, No. 1, February 1998) and the Monteverde Reserve of Costa Rica (the complete extinction of Bufo periglenes, the Golden Toad, may possibly be based on the chytrid fungi- if not caused by hard UV-B radiation!). Soon more bad news came from Nicaragua (southern shore of the Lake Nicaragua: dying hylid frogs in masses), then from the rainforests of Australia (Lee Berger et al. 1998) and from the Atlantic forests of Brazil (Weygoldt 1989)! It seemed, that whole species assemblages disappeared as by magic and within an extremely short time lapse! In Peru we heard the first time from such exterminations during a visit of Bill Duellman in 1991, when he commented a possible fast extinction of the common and widespread Andean Atelopus ignescens from the Altiplano of Southern Ecuador. In these years, the Declining Amphibian Population Task Force (DAPTF) was founded in the USA and the author started to survey the amphibian populations of North East Peru and especially those of the Region San Martin for our Peruvian branch of the DAPTF under the leadership of Dr. Antonio Salas. Some bad notices came too late to Tarapoto, like the extinction of the famous Golden Toad Bufo periglenes from the Monteverde Reserve in Costa Rica, which we could have saved from extinction when alarmed at time when the first dead toads were found in the field!
Writing these lines in February 1999, the news from more extinctions in Australia and Panama appeared even in Peruvian newspapers and the installation of a Chytrid web site in INTERNET(http://www.mycoinfo.com/frog-chytrid.htmlpathologists) with latest news from the chytrid front (as we call it now) helped to organize and to join the different scientists and institutions which work with this possibly new genus and species of fungi. Recently, the fungus had been determined and named: Batrachochytrium dendrobatitis gen et sp. nov. LONGCORE, PESSIER & NICHOLS 1998. It seems, that the Chytrids had been present since 1988 (see Nichols et al. 1998 for a resume) in some frogs which died in Zoos. The problem was, that the disease was long time confounded and thought to be caused by an unicellular protozoic flagellate- when in reality this was a zoospore with flagellum from a very dangerous fungi of the genus group Chytridiomycetes, which are known to be saprobic in aquatic or terrestrial habitats and some are parasites of other fungi, algae, vascular plants and invertebrate animals (see Nichols et al. 1998). But it seems that there was no detection so far from vertebrates. The paper of Nichols et al. indicates, that Chytrids had been responsible for a lot of amphibian deaths in the collections of other zoos or institutes, affecting frogs and salamanders from all continents. The dying of 24 juvenile blue poison dart frogs (D. azureus), 4 D. auratus, 3 adult Litoria caerulea and one Horned frog Ceratophrys cornuta in the years 1996- 1997 in the National Zoological Park, Smithsonian Institution, Washington, DC, gave the first impulse to investigate the problems in detail and the involved chytrid fungus was finally detected. Sometimes, it had been confounded in the past with other fungi- diseases (Basidiobolus ranarum) or the extinctions were attributed wrongly to UV- B radiation effects. It seems, that most of the different species of frogs from nearly all continents in the paper of Nichols et al. had been infected in the Zoos- but this will mean, that frogs and some salamanders from around the world HAVE NO DEFENSES AGAINST THIS DISEASE and it is in no case an effect of a "debilitated defense system" of only "some" frogs as some researchers assume! Until now, nobody knows exactly when and where this new fungus appeared for the first time- some people think, that the pathogen had been introduced from another continent to the Monteverde Rainforest Reserve in Costa Rica, perhaps with earth rests on shoes or camping gear of the ecotourists or some travelling scientists and started from there to the South and North, killing all amphibians which visit quebradas, ponds or lakes. At the moment are resisting the Eleutherodactylus species with direct development and some frog and salamander species which use phytotelmata, but the situation of the stream bank hylids and all Atelopus species is absolutely critical and may include in the next months and years the terrestrial dendrobatid frogs like all Colostethus, all Phyllobates and all Dendrobates auratus/speciosus of Centro- America. Data from the current range of the disease indicate a spread-out speed of 50 - 100 km/ year to Nicaragua and towards Colombia!
Costa Rica and Panama are very small countries and most of their outstanding amphibian fauna may have gone forever in a few years from now! At the moment (August 2000) a lot of rainforest frogs are extinct in wide ranges of Centro- America- especially in the highlands- and NO recuperation could be observed. The once common chorus of amphibians in those forested valleys now changed to a deadly silence, only interrupted by the lonely cries of some birds! The list of extinctions is getting very large now and at least the author is running against time to save all Epipedobates tricolor variants of Ecuador with a new strategy.
The infections of so much frogs in the Zoos happened possibly by the mixing of the species and insufficient quarantines of newly imported or interchanged amphibians! The primary focus of contamination possibly came from the Australian frogs. If the Zoospores enter once into the water containers of the terrarias in a public exhibition, all frogs can get infected which touch this water = BIOHAZARD! If the terrarias have communicating water pipes between all containers, the disease may spread over the whole installation as it is observed also with the reptile-dermatomycosis (the author's own experience from the Wilhelma Zoo at Stuttgart). Today, the commerce and illegal smuggling of wildliving animals and amphibians is a worldwide business and ecotourists travel around in all continents- therefore the introduction and distribution of a strange disease is very easy (see the AIDS problem in humans for example!). In the authors opinion the research has to concentrate as fast as possible on the facts how to stop and how to treat this disease. We can take for sure now, that the amphibians in the areas where the chytrids are acting (and yet do not act!) have NO NATURAL DEFENSES (are naive populations!) against this disease. It is absolutely useless to waste time and look for a reason why chytrids can infect and kill the frogs- they simply do it and this is valid for most known species which depend on water from quebradas, rivers or ponds/lakes all over the world! If the chytrids get more distributed by mechanisms we still do not know (a dormant stage may be involved, too, which may be distributed by migrating waterbirds!), the situation will turn extremely dangerous for all ecosystems: we must not forget that amphibians are an important food source for other animals and control insects in the forests and cultivated fields! We urgently have to get on data of the survival of the zoospores in water (without finding a host) or under dry conditions, their thermal preferences and limits, the transmission pathways and possible intermediate hosts or carriers (fishes, watersnails, crabs, waterbirds?). We need to know immediately, which agents can kill the zoospores: solutions of methylen blue, malachite- green, salt solutions or antiflagellate- medicines like FLAGYL or others. We need to know how long may stay the zoospores alive in the quebradas after the first killing wave had passed? We have to know, if we can reintroduce safely the killed frog species from other areas not yet affected to restore the original amphibian communities of the now "silent rainforests" and a lot more. Writing this lines, unique species communities are dying out there every minute and we should urgently concentrate on the efforts how to combat these chytrids and how to stop their expansion! The Atrato swamp is no barrier for this water contagiant fungus to jump over to South America as it was for other epidemic diseases! So we have to act fast!
Newest informations (March 2000) came from Europe and Ecuador: Chytrids are killing frogs in Ecuador and in a lot of the European breeder terrarias and some people are selling infected frogs around Europe. Chytrids are recorded recently from terrarias in Germany, Denmark and Sweden, possibly introduced with smuggled frogs from original habitats of Centro-America. If the Chytrids may escape from the terrarias (waste water infected with zoospores!), then the European amphibians might go extinct! The temperature range this chytrid prefers is falling into the range of European amphibians!

 

A mixture of 0.3 mg Methylene blue and 2 mg Benzalkoniumchloride in 1000 ml will kill the zoospores of the fungus. This is tested out in Holland. They use this solution to put the eggs in and also the tadpoles for the entire times(H.C.).

Dendrobates speciosus could not be found any more in its original habitats (Ron Gagliardo, USA, pers. com., March 2000) and might go or even is extinct now! The same is valid for Dendrobates arboreus (Charles Nishihira, pers.com. 2000). We need urgent rescue programs for those species and an expedition to find some surviving frogs to start an emergency management in controlled cages, where we can eliminate zoospores and treat the frogs against the Chytrids. The way how the chytrids can affect normally safe arboreal frogs might function via the Hylids: as we know, arboreal Hylids like the Agalychnis for example come down to streams or ponds to interchange water or to restore daily water losses. Then they can get infected there by the chytrid zoospores, which later the frogs carry up into the canopy and perhaps into the bromeliads, where the arboreal Dendrobatids might get infected. We urgently must check the phytotelmata water in the range of D. arboreus, if it contains chytrid zoospores!

All dendrobatid frog breeders or breeding farm operators should be able to recognize this disease in the future to avoid the contamination of their installations and here are the known facts of this new Chytrid fungi, together with two microphotos provided as a courtesy of Dr. David Green, USA, via Dr. Jack Frenkel, Sta. Fe, USA, which show microscopic details of this disease, taken from dead Bufo haematiticus. Very illustrative papers are the one from the Australian research group around Dr. Lee Berger (Lee Berger et al. 1998) and the one of the American working group of Joyce E. Longcore, Allan P. Pessier and Donald Nichols (1998), which gave the name to the chytrid and investigated its relations to other similar fungi. But why is this new chytrid fungus so lethal and what do we know currently about this very dangerous disease?

 

ORIGIN:
According to Lee Beger et al. 1998 and the paper from the Zoo-veterinary group (Donald K. Nichols et al. 1998, Longcore et al. 1998) we can summarize the following facts:

The new fungi belongs to the phylum Chytridiomycota, which are heterotrophic fungi which are living all around the world in soil and water as saprophytes, degrading substances as chitin, plant detritus and keratin. Some of the different genera are obligate or facultative anaerobes and a lot are parasites of such different things like other fungi, algae, vascular plants, rotifers (!), nematodes (!), or insects (!) (and marine crustaceans- Perkinsus?). This new one seems to be the first member of the phylum affecting vertebrates and especially the more delicate amphibians. Similar chytrids caused some severe diseases in professional insect cultures, where they can be eliminated by a short time exposure of the culture to 60° C (see Wyniger, 1974), but this treatment we cannot apply to delicate amphibians!

INFECTION WITH THIS CHYTRIDS:
Data from the first literature records indicate, that adult frogs and tadpoles of montane riparian rainforest habitats are infected, but the records from the dead frogs of the different Zoos, frog farms or the Lake Nicaragua (!) give evidence, that there may be no altitude nor secure temperature limits for the pathogen! (But there perhaps may be chemical limits like salinity, pH or other still uninvestigated factors- the author). The only amphibian species which may resist or survive the cutaneous chytridiomycosis are those which use independent water resources in the forest like phytotelmatas, tree holes and other places not connected to the riparian, pond- or lake- environments or frogs which have a direct development in the egg like most Eleutherodactylus! There are observations from the Queensland rainforests, that perhaps species with high egg numbers in their clutches may survive the chytrid killing-wave and there is another observation, that the chytrid infects especially the keratinized mouthparts of the tadpoles, destroying the teeth rows and the keratinized jaws, which may cause a deficient alimentation of the tadpoles and their death. But juvenile postmetamorhic froglets showed to be free from the chytrid infection (because during MET, the keratinized mouthparts are eliminated and give way to the common mouth and jaw design we know from the froglets and adults). The author supposes, that the REINFECTION of the froglets functions via the free swimming zoospores, permanently present in the water of their habitats!
It is important to know, that Batrachochytrium dendrobatitis infects primarily KERATINIZED SKIN - as toe pads, tarsal- and other tubercles, other keratinized parts mostly of the ventral skin. This would be no mayor menace, but the peculiarity of amphibians is, that they have a special highly vasculated and delicate skin region, where they use cutaneous respiration, interchange of minerals, excretion of metabolism-waste and osmoregulation- this part of the pelvic skin is called the DRINK PATCH (Trinkfleck). Everybody who kept or keeps hylid frogs in a glass terraria knows the white mineral coatings of the glass walls at the preferred DRINK PLACES of the frogs, which we usually must clean from time to time with a razor blade or acid solutions! The new chytrid just infects this drink patch area with a structure called thallus, which bears a network of short, filament like rhizoids to anchor the thallus in the epidermis and "smooth walled, spherical to subspherical, inoperculate sporangia" (see Lee Berger et al.,1998, p. 9035 and the figs. in Longcore et al, 1998). (It is to mention here, that this type of fungi does not develop the extensive mycelia known from other fungi!). The sporangium produces this typical and strange single discharge- tube, which protrudes the infected skin and from where the zoospores are released or better ejected into the surrounding water! The location of the thalli and sporangias are in the stratum corneum, stratum intermedium and stratum granulosum.
The zoospores are another strange structure, very similar to common protozoic flagellates with one whip-lash flagellum, but develop from an amoeboid like structure! (Pessier, Nichols, Longcore & Fuller, 1999). Therefore this disease had been confounded obviously a long time! Fig. 4 in L. Berger (1998) and others in Pessier et al. 1999 show the detailed ultrastructure of such a zoospore and for us is important to know, that those zoospores swim actively by the movements of the whip-lash flagellum! The tests of the team around Lee Berger indicate, that the time from infection and death of the frogs are 10- 18 days. It is to add here, that the disease is absolutely fatal for all infected frogs!
At present state of knowledge, each chytrid infected frog must be classified as a very dangerous BIOHAZARD, the same is valid for the water which comes in contact with infected frogs! This is especially important for Zoos and amphibian producing laboratories or breeding farms! If we discharge UNPROCESSED INFECTED WATER from Zoo- or farm installations into natural ecosystems - there may be an introduction of this disease to local native (and unprotected or naive) amphibian faunas, creating more amphibian holocausts. On the base of the infected Zoo- frogs and salamanders from all around the world there is virtually no amphibian species, which CAN RESIST this fatal disease. In Australia, even the extremely resistant Bufo marinus is dying out! On the list of infected species in the wild or from Zoos or breeding farms are the hylids Litoria from Australia, Clawed frogs (Hymenochirus) from Africa, Mantellas from Madagascar, other Bufos from the USA, Bufo viridis from Europe, neotropical Bolitoglossa- Salamanders, Leopard frogs (Rana), several species of poison dart frogs from Central America (in the wild and zoos) and several other species of Zoo- maintained frogs!

RECOGNITION OF THE DISEASE:

To recognize a chytrid infection in amphibians is not easy in the early stages! Tadpoles may be checked under a good dissecting microscope: we have to look for destroyed teeth rows or jaws.
Adult frogs may be tested, revising the ventral area (drink patch), finger discs and other keratinized structures with a powerful dissecting microscope: we have to look for the changes in the pelvic skin or a bad or incomplete shedding, combined with color changes of the ventral skin: brown, hyperkeratinized areas, red zones of infections etc.. If we see a frog sitting more time in the water than usual and with hanging brown skin rests along the flanks or the venter, we have an infected one! Like during other frog diseases, dying frogs seem to return to the water- and this increases the successful infection of other frogs via the water of quebradas or ponds.
We can make a next test with swabs or soft scrapings of cell samples from the drink patch area or check a cutted toe disc under a powerful light microscope to see alterated cells with protruding heads of the discharge tubes or the very small zoospores with an single flagellum.

DEFENSE OF THE FROGS AGAINST THIS DISEASE:

It seems, that this chytrid infection is so dangerous, because the frogs have no opportunity to combat this fast acting disease (naive populations against a highly virulent parasite). The immunological system of frogs is in general very rudimentary if compared with the mammalian system and therefore not very effective against parasites (see the other problems with other frog diseases mentioned above) and according to the current observations, the frog tries to defend itself by accelerated skin growth and shedding to get rid of the intruders.
Very strange is, that there are little defense reactions of the immunological type: there are only very few red areas, where the combat cells in the blood and from the lymphatic system attack the intruding fungi! If the frog covers its most important cell layers of the drink patch with thicker skin, this affects all his basic metabolism functions in a fatal way! The osmoregulation, the oxygen interchange, the elimination of metabolism waste or surplus minerals, the water uptake (drinking) is severely hindered and obviously in the last stage of the disease completely impossible! The frogs suffer from one of the most cruel deaths one can imagine! There may be an additional cause present for the death of the frogs: the release of highly toxic metabolism substances of the chytrid fungi which may kill the frog (see L. Berger et al.,1998, p. 9036).

TREATMENT OF THE CHYTRID FUNGUS:

No secure treatment is currently known and according to Dr. J.K. Frenkel (pers. comm.) a medication will be difficult. There are latest attempts to make treatment tests against the fungi with the following medicaments: Benzalkonium chloride, fluconazole and itraconazole (Dr.Lee Berger, email comm. 22.2.1999) or Amphoterycin B
(Dr. J.K. Frenkel, lit com.). Other proposals of treatment see the Website of the Australian chytrid investigation group:
http://www.jcu.edu.au/dept/PHTM/frogs/amphdis.htm under ANZCCART.

A treatment of infected frogs in original rainforests would be the required strategy, but this is virtually impossible! (or not?).
We can attack the chytrids by several ways in intensive installations and Zoos, but this is very difficult in the field!
First of all, every infected frog discharges constantly highly virulent zoospores, when sitting in the water! To avoid the distribution of the zoospores, we have to kill them constantly. There are some agents from the aquaculture (methylene-blue, malachite-green, or the Gentiana- violet) which may be tested, other medicines are known from the aquarium fish industry. The author recommends testing weak solutions of FLAGYL (from humane medicine) or similar agents, which kill flagellates. Baths in salt- solutions may be another form to try to attack the zoospores, perhaps altering the ph may function, too! As we know nothing about the chemical and biological resistance (dry up, heat or cooling) and life span of the zoospores, the author currently can make no more proposals. Perhaps there are "weak points" in the biology of the zoospores, where a medication can attack. If we use quarantine terrarias, we may filter the water over UV- equipment, Diatomaceous-beds, ceramic water purification cartridges, molecular filters and other modern gear to get rid of the zoospores!
To treat adult frogs may be more complicated, perhaps we have to look for a two-way method: attack the fungi from outside and from inside the body. If we can induce an accelerated production of new skin and the fast shedding of the infected layers, we may have a chance. The problem of an external treatment is, that the fungi is well protected in the deeper skin layers (stratum granulosum) and we cannot use creams or other agents, which will obstruct the drink patch! Perhaps we have medicines from human or vet applications, which we can test in frogs? We need urgently to do something and the author ask all persons which anti- fungi treatment experience to communicate with the INIBICO to develop proposals to combat this rainforest amphibian holocaust!
Ponds and similar bodies of water we may treat in the field if we find an agent tolerated by all the other higher water organisms, but streams, rivers and quebradas are impossible to manage. The only way to act in rainforests is to wait until the killing wave passed by and later trying to reintroduce the exterminated species (via tadpoles) from still "clean" rainforests or by use of infected, but treated tadpoles (which is successful at the moment- Lee Berger) from the same species assemblage. But we have to know, how long may stay the zoospores alive without finding a host frog or intermediate carriers and we have to discover the dormant stages of the Fungus! Newest informations from Central America show, that a recovery of affected landscapes is not observed: the gone species are virtually EXTINCT and wiped out forever!

Another very important point is NOT TO ACCELERATE THE SPREADING OUT OF THE DISEASE! We do not know, if waterbirds (or tourists) may carry the zoospores or DORMANT STRUCTURES to other places far away and start perhaps new focuses all over South America, Africa, Europe and the USA? The method of introduction of the chytrids to the Monteverde or Fortuna reserve has to be investigated in detail: if ecotourists may distribute the pathogen, we will have a WORLDWIDE RED SITUATION! The author for example makes it now obligatory for all his visitants to use NEW SHOES and no equipment (catching nets etc.), which had been used previously in the infected countries! A lot of frog fans travel around the world: Panama and Costa Rica are one of the most visited places, followed by Peru and Ecuador, and the danger of a contamination of still "clean" areas may be higher than expected! Newest information from COSTA RICA and PANAMA indicate, that the Chytrid problem is kept SECRET, possibly to avoid an impact on ecotourism and big financial losses. But this is the worst way to treat with this dangerous amphibian holocaust. And as the Ecotourists still are walking around unwarned, the disease is spreading out without any control and even boosted by the frog smugglers- see the recent infections showing up in Germany and neighboured countries!

All frog keepers (this includes all Zoos, breeding farms and public exhibitions) should make an immediate check, if their frogs are infected by Batrachochytrium dendrobatitis and if the result is positive, to treat them as a BIOHAZARD with all the necessary strategies to protect other frogs and natural environments from this disease. Everybody which purchases or collect frogs for keeping them in terrarias or public exhibitions should strictly use a quarantine of at least two months and check the specimens with the methods mentioned above.
For the chytrid researchers, there is a listing in the Appendix to direct an international investigation on this outstanding disease, the most dangerous one for the amphibians living on our planet!

For the treatment and medication of dendrobatid frogs there are some principal rules we should never forget:

Like reptiles and all other amphibians, frogs grow by changing their skin in regular or irregular intervals. The specialty of frogs is, that they eat their skin during the shedding process (called dermatophagy, see Weldon et al. 1993 for an overview). In dendrobatids, we have to stand up very early in the morning to be witnesses of this process in the terrarium, which takes place during sunrise and is perhaps the first activity the frogs are dedicated to in the morning. But to confirm this, we need more video recordings of this behaviour. During the shedding, which may last several minutes and is preceded by the sweating out of a transparent liquid to facilitate the shedding process, the frogs are defenseless to predators. The old skin opens at the head first and then the frog pushes the skin in his mouth and later helps with the hands and special body arching movements to open the skin- perhaps along special seams like an old jeans and to pull and push it into the mouth. In such tiny dendrobatids like D. variabilis or D. imitator, this is quite a hard procedure for the frog and after the process he will be very exhausted. After the shedding, the frog usually starts with the feeding cycle.
The problem starts, if we have to apply bad tasting medicines (antibiotics), vitamins or special vermicide baths: in such cases the frog refuses to feed on the skin and therefore cannot tear it off. This will soon cause the death by interruption of the vital skin functions we discussed above in the chytrid paragraph. Medication of dendrobatids today is best done by giving drops of the medicine or vitamins onto the dorsal skin, which transports the agents into the body. This is a very good method and better than to inject or force-feed the animal! Therefore we have to check with caution after each medication, if the treated frog changed its skin completely. Otherwise we have to help him to get the skin rests off (weak salt baths or baths in correctly temperated water are a good emergency treatment and we can help with a pair of scissors or a soft brush to get the old skin away! If we forget this, the frogs may die very fast!
The author wants to remember here the problem of the D. histrionicus shipments: if a few frogs in one shipping box have highly pathogen agents on their skin, they may smear the pathogen onto other frogs and those will get the pathogens in their stomach and intestine tract during the shedding process, causing those mortal mass-infections of the intestine and the liver observed on most D. histrionicus sample frogs from the mass-dying events! And this may be the same way how to transmit the leprosy like Knochenfrass to other frogs or the virus from the exteriors of a rainforest habitat into the body, where they can start their fatal infections! Long time we thought, that the frogs toxins have the function of antibacterial and antifungal shields, but now the author is not sure of such statements. One toxin, the alkaloid Samandarine from the European Salamandra salamandra had been reported to have bacteriostatic functions (Habermehl 1977). Hylid frogs and especially the Phyllomedusas have skin secretions which may protect them against bacterias and virus diseases- the parallel check of a numerous series of rainforest frogs from the chytrid localities showed the absence of other infections and apart of the mortal chytrids, the frogs commonly were very healthy (!) - but see the virus infected D. granuliferus and D. tinctorius! Dendrobatids are storage containers for arthropod toxins- and antibacterial effects of such toxins may be only casual! We urgently need more investigations on such matters, but the above mentioned points will help to avoid the death of frogs!

There is a lot of literature and treatment proposals of amphibian diseases scattered in the hobbyist and Zoo- veterinarians literature, but there is lacking one work about such problems, which summarizes and describes newest results and treatments. Recently, one book is on the market: Dr. Frank Mutschmann: Erkrankungen der Amphibien, Parey, Berlin. The author had not yet the possibility to revise it. We need furthermore urgently an amphibian virus working group, apart of the chytrid group, to resolve the severe problems discussed in this chapter. Every frog breeder, who had success with a treatment or can contribute with own experiences may contact the INIBICO via Email to prepare an update of this chapter for the final printing.

The author includes here a selected table of diseases which affect especially dendrobatid frogs and their possible treatment, other advices can be obtained from special literature (see Reichenbach- Klinke 1961 or newer editions, Schulte 1980/84, pp. 80-91, diagnosis and treatment tables; Van Rossum 1990, Claessen 1988+ 1989; Jaeger, F. 1986, F. Mutschmann 1998 and others).

If we are working with dendrobatid management projects, we should check some frog samples, if there are parasites at the locality present. Problems with adult frogs we can avoid during management, if we use the ranching methods like the ZIRA and ZIR and recollect tadpoles or eggs and process them in well controlled intensive installations. This is the recommended method if we have to work in areas, where virus diseases are naturally present (Costa Rica, French Guyana!). We have to examine well the froglets growth cages for unicellular parasites or nematodes/other worms present. Urgent investigations should be done in Colombia to track down the problems of the mass-killing of the D. histrionicus frogs in shipments from this country!

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