http://www.collembola.org/publicat/oncopodu.htm - Last updated on 2008.04.29 by Frans Janssens
Checklist of the Collembola: A new cave species of the genus Oncopodura (Collembola: Oncopoduridae) from Belgium.

Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium
Louis Deharveng, Laboratoire d'Ecologie Terrestre, UMR 5552 du CNRS, UPS, Toulouse Cedex 4, 31062, France

Abstract

Coming soon...

Keywords: Collembola, Oncopoduridae, Oncopodura, Belgium

Under construction. Contineously being revised.

Introduction

Among specimens from the Delhez collection sent to me by Dr Michel Dethier for identification, several specimens were found of Oncopodura that do not fit with the described species cfr Absolon & Kseneman 1932, Gisin 1960, Palissa 1964, Szeptycki 1977, Mari Mutt 1984, Deharveng 1988, Christiansen & Bellinger 1996. The species that comes closest to these Belgian cave specimens is Oncopodura egerszoegensis Loksa, 1961:237, especially if you compare PAOs (based on the description of Palissa 1964:237). Note that Szeptycki 1977 does not list egerszoegensis in his key.

Deharveng (19...) identified some Oncopodura cf. reyersdorfensis and nov. sp. specimens, probably new and "troglomorphic" Belgian Oncopodura, in the material of Dethier and Hubart.
Christian (1998:51) records a new Oncopodura sp. for Austria. The lobed PAO tubercles relate to those of Oncopodura reyersdorfensis Stach, 1936. Christian suggests that reyersdorfensis should be revised.

Oncopodura is a very difficult genus, difficult to prepare to see tergite chaetotaxy and analysis of antennal chaetotaxy is a bit tedious. The specimens are in not too good condition, so it will be a though job to study the features in more detail. We do not have egerszoegensis type specimen for comparison (even if available, it is likely that it will be in so poor state that its chaetotaxy would be impossible to analyse). In fact there is little chance that the Belgian species is the same as egerszoegensis, they are far and probably cave endemics (?).

To be completed...

Materials and Methods

Specimens have been collected using ... In the laboratory, the contents was treated with ..., and the collected specimens were preserved in ethanol 70%???.

The specimens were previewed using a stereomicroscope (magnification max. 50x).

All specimens were mounted in a drop of Hoyer medium on standard object slides, and covered with a square cover glass of 18x18 mm. After drying for a week at room temperature, the cover glasses were 'ringed' with transparant nail polish to seal the Hoyer medium.

Final determination was done using a binocular phase-contrast compound microscope at 10x100 magnification with immersion oil.

The genus level identification is based on Bellinger & al. (1999?-2004). The species level identification is based on ... The nomenclature is based on Bellinger, Christiansen & Janssens (1996-2005).

Oncopodura speciesnovumbelgicaensis Deharveng & Janssens new species

Type material. Collembolans were collected by Dr from the .... on May 9, 2003.
The holotype has been deposited in the XXXX collection of the YYYY and the paratypes in the collection of the University of Antwerp, Belgium. Other material in the private collection of Dr ....

Legend of the columns
 1Provence
 2Station (for more details see above)
 3UTM (10 x 10 km)
 4Date (year - month - day)
 5Number of specimens (adult, exemplaires, female, juvenile, male)
 6Name of legit
 7Name of determinator
 8Collection(s) where the specimens are deposited

Inventory

Familia Oncopoduridae Carl & Lebedinsky, 1905

Oncopodura speciesnovumbelgicaensis Janssens, F et Deharveng, L, 2005:ip

   Liè  Comblain (abîme)      FR89 1999-02-18 1a        Hubart JM & Dethier M  Janssens F             Dethier2 M @UACM
   Liè  Comblain (abîme)      FR89 1999-02-18 1a        Hubart JM & Dethier M  Janssens F             Dethier2 M @UACM
   Liè  Steinlein             FR89 1999-04-22 3e        Hubart JM & Dethier M  Janssens F             Dethier2 M @UACM
   Liè  Steinlein             FR89 1999-04-22 2e        Hubart JM & Dethier M  Janssens F             Dethier2 M @UACM
   Nam  Fayt                  FR65 2000-12-02 1a        Rochez G               Janssens F             Dethier2 M @UACM
   Liè  Trou Manto            FR59 2000-12-09 3e        Rochez G               Janssens F             Dethier2 M @UACM
   Nam  Fayt                  FR65 2001-05-19 1e        Hubart JM & Rochez G   Janssens F             Dethier2 M @UACM
   Nam  Fourneau              FR67 ????-mm-dd ?e        Delhez F?              da Gama M et al        Dethier2?
   ?    grotte                ?    ????-mm-dd ?e        Delhez F               Delhez F               Dethier2?
   ?    grotte                ?    ????-mm-dd ?e        Delhez F               Delhez F               Dethier2?

Derivatio nominis. Coming soon...

Description.

  1. Fig.1. Oncopodura nov. sp. habitus.
    Frans Janssens © 2005.
    A general habitus of the species
    Length 0.7-0.8 mm (more like crassicornis). Oncopodura egerszoegensis is at least twice as large: 1.8-2 mm. Oncopodura reyersdorfensis is about 1.6 mm (Stach 1936:134).
  2. Fig.2. Postantennal organ, dorsal aspect.
    Frans Janssens © 2005.
    Fig.3. Postantennal organ, lateral aspect.
    Frans Janssens © 2005.
    Fig.4. Postantennal organ, dorsal aspect.
    Frans Janssens © 2008.
    The PAO is very characteristic even if similar to Oncopodura egerszoegensis. The PAO seems to be more variable with respect to the number of lobes of the PAO tubercles (2 to 5 lobes) and with respect to the length of the lobes. See my preliminary drawings of the PAOs of a few specimens. Notice long and short lobes of one and the same tubercle. Notice tubercles with 2 lobes, 3 lobes and 4 lobes of one and thesame PAO. The number of PAO tubercles seems to be constant = 6. So it seems to fit in the crassicornis species group as defined by Deharveng (1988:134).
    The number of incisions of the PAO tubercles is variable: 1-4. Also Loksa noticed among his 30 specimens 11 ones with 1 deep incision in stead of the typical 2 less deep.
    Fig.2: dorsal view of the PAO showing clearly the variable and asymmetrical structure of the 6 tubercles of the PAO. Fig. 3: transversal section of the lateral view of the PAO shows the 'leaf-of-a-composite-flower'-like position of the PAO tubercles. Apparently, the 6 tubercles arise from a central stem/papilla. Fig. 4: dorsal aspect of PAO in the Carl Zeiss Laser Scanning Microscope 510. Image made by Jan Van Daele of the University of Antwerp, Belgium (obj. 63x oil immersion).
  3. the distal part of tibiotarsus of leg II in lateral view, with claw, empodium and the enlarged dorsal chaeta of the tibiotarsus.
    Lateral tooth on the unguis is absent.
    Conspicious spoonshaped 'tenent hair' on mesotibia. Note: absent in reyersdorfensis (see Stach, 1936:133).
  4. the mucrodens in external and internal view, with all chaetae displayed.
    spines on dens = 2 proximal and 3 distal;
  5. the chaetotaxy of abd.V tergite, simple, but not easy: the tergites are like if they were covered with wax, so usually more or less opaque in Oncopodura. Strange genus!
  6. the antenna : its dorsal chaetotaxy, AND also the ventral "S-chaetae" or "sensillae" are probably important to draw.
    Several antennal sensilla present.

To be completed...

Discussion

Coming soon...

Acknowledgements

We would like to thank Dr Michel Dethier for sending the specimens for identification, Jan Van Daele for making the Laser Scanning Microscope images.

References