TopFrogs

There are around 3,900 species of tailless amphibians, including the frog and toad.

True Frogs

When we think of frogs, we generally picture what are called "True Frogs",
members of the family Ranidae, containing more than 400 species.
These frogs have the characteristics of:

two bulging eyes
strong, long, webbed hind feet that are adapted for leaping and swimming
smooth or slimy skin
Frogs tend to lay eggs in clusters.
Frogs from this family can be found on every continent except Antarctica. They are referred to as the "true frogs" because of their generalized body form and life history: the so-called generic frog.
Members of this family include the bullfrog, common frog, green frog, leopard frog, marsh frog, pickerel frog, and wood frog. Top

Life Cycle

When Frogs mate, the male frog tends to clasp the female underneath in an embrace called amplexus. He literally climbs on her back, reaches his arms around her "waist", either just in front of the hind legs, just behind the front legs, or even around the head. Amplexus can last several days! Usually, it occurs in the water, though some species, mate on land or even in trees! While in some cases, complicated courting behavior occurs before mating, many species of frogs are known for attempting to mate with anything that moves which isn't small enough to eat!  While in the amplexus position, the male frog fertilizes the eggs as they get are laid. Frogs tend to lay eggs single eggs in masses.  Top

Eggs

Frogs tend to lay many many eggs because there are many hazards between fertalization and adulthood. Those eggs that die tend to turn white or opaque. The lucky ones that actually manage to hatch still start out on a journey of many perils.
Life starts right as the central yolk splits in two. It then divides into four, then eight, etc. Soon, the embryo starts to look more and more like a tadpole, getting longer and moving about in it's egg. Usually, about 6-21 days after being fertilized, the egg will hatch. Most eggs are found in calm or static waters, to prevent getting too rumbled about in infancy!
Some frogs, like the Coast foam-nest treefrog, actually mate in treebranches overlooking static bonds and streams. Their egg masses form large cocoon-like foamy masses. The foam sometimes cakes dry in the sun, protecting the inside moisture. When the rain comes along, after developement of 7 to 9 days, the foam drips down, dropping tiny tadpoles into the river or pond below. Top

Tadpole

Shortly after hatching, the tadpole still feeds on the remaining yolk, which is actually in its gut! The tadpole at this point consists of poorly developed gills, a mouth, and a tail. It's really fragile at this point. They usually will stick themselves to floating weeds or grasses in the water using little sticky organs between its' mouth and belly area. Then, 7 to 10 days after the tadpole has hatched, it will begin to swim around and feed on algae.
After about 4 weeks, the gills start getting grown over by skin, until they eventually disappear. The tadpoles get teeny tiny teeth which help them grate food turning it into soupy oxygenated particles. They have long coiled guts that help them digest as much nutrients from their meadger diets as possible.  By the fourth week, tadpoles can actually be fairly social creatures. Some even interact and school like fish!  After about 6 to 9 weeks, little tiny legs start to sprout. The head becomes more distinct and the body elongates. By now the diet may grow to include larger items like dead insects and even plants. The arms will begin to bulge where they will eventually pop out, elbow first. After about 9 weeks, the tadpole looks more like a teeny frog with a really long tail. By 12 weeks, the tadpole has only a teeny tail stub and looks like a miniature version of the adult frog. By between 12 to 16 weeks, depending on water and food supply, the frog has completed the full growth cycle. Top

Eating

Some frogs have tongues that are long and sticky that can be used to catch bugs. These roll out like an upside-down party horn and snap at the bug! When a frog swallows a meal, his bulgy eyeballs will close and go down into his head! This is because the eyeballs apply pressure and actually push a frog's meal down his throat! Most frogs have teeth of a sort.
They have a ridge of very small cone teeth around the upper edge of the jaw. These are called Maxillary Teeth. Frogs often also have what are called Vomerine Teeth on the roof of their mouth. They don't have anything that could be called teeth on their lower jaw, so they usually swallow their food whole. The so-called "teeth" are mainly used to hold the prey and keep it in place. Top

Hearing

Frogs can hear using big round ears on the sides of their head called   tympanums. Tympanum means drum. The size and distance between the ears depends on the wavelength and frequency of a male frogs call. Ever wonder how frogs that can get so LOUD manage not to hurt their own ears? Some frogs make so much noise that they can be heard for miles! How do they keep from blowing out their own eardrums? Well, actually, frogs have special ears that are connected to their lungs. When they hear noises, not only does the eardrum vibrate, but the lung does too! Scientists think that this special pressure system is what keeps frogs from hurting themselves with their noisy calls! Top

Jumping

Frogs are one of the best leapers on the planet! Did you know that frogs can launch themselves over 20 times their own length using those big strong legs of theirs? That would be like if you could jump 100 feet!
The average flea can jump up to 150 times its own length.
A kangaroo can leap about 4 1/2 times it's length.
Elephants can't jump at all!
The longest frog jump on record measured 33 feet 5.5 inches. It was made by a frog named Santjie at a frog derby held in South Africa. Top

Skin

Frogs have very special skin! They don't just wear it, they drink and breathe through it.
Frogs don't usually swallow water like we do. Instead they absorb most of the moisture they need through their skin. Not only that, but frogs also rely on getting extra oxygen (in addition to what they get from their lungs) from the water by absorbing it through their skin. Because frogs get oxygen through their skin when it's moist, they need to take care of their skin or they might suffocate. Sometimes you'll find frogs that are slimy. This is because the frog skin secretes a mucus that helps keep it moist. Even with the slimy skin, these frogs need to stay near water. In addition to jumping in water, frogs can get moisture from dew, or they can burrow underground into moist soil. Frogs shed their skin regularly to keep it healthy. Some frogs shed their skin weekly, others as often as every day! Top

Life Span

Very little is known at all about the natural lifespan of frogs. Partially, this is because it's pretty hard to track a frog all its life. However, some records show that in captivity, many species of frogs and toads can live for surprisingly long times. They seem to generally average somewhere between 4 and 15 years!

The longest lifespan recorded was a European Common Toad at 40 years.

Giant Toad ranging between 7 and 24 years

Green And Black Poison Dart Frog ranging between 7 and 17 years

Oriental Fire-bellied Toad ranging between 11 and 14 years

Ornate Horned Frog ranging from 5 to 12 years Top

Predators

There are a wide variety of frog predators. Animals that eat frogs include snakes, lizards, birds, and various small animals like hedgehogs. Even under water frogs cant be safe from hungry sharp toothed fish, swimming mammals like water shrews, and even diving birds! As if that wasn't bad enough, frogs even have to watch out for other hungry frogs!

The largest enemy that frogs have is pollution. Frogs are becoming particularly important as factors in measuring the health of the global environment and in tracking how much ultra-violet light gets into our atmosphere. For some years now, it has been noted that worldwide frog populations have been in the decline. Many species are on the verge of extrinction, while others are thriving well. Only recently has this frog population change been linked to not only a decrease in upper atmospheric ozone layer, but also an increase in low-atmosphere ozone due to pollution. Top

Biggest/Smallest

The biggest kind of frog is the Goliath frog. They come from Cameroon in West Africa. Their bodies can reach the size of nearly a foot (30 cm) long. The Conraua Goliath weighs as much as a large housecat, about 3.3 kilos!

The smallest frog in the Southern Hemisphere is the Gold Frog, or Brazilian Psyllophryne Didactyla.
Adult Gold Frogs measure grow to only 9.8 millimetres in body length. That's about one centimeter or about 3/8 of an inch!  Top