Frogs
Frogs are members of the Amphibian family,
which are cold-blooded (poikilothermic) vertebrates. They differ from reptiles in their
absence of scales and, for the most part, return to the water to breed. There are about
3,900 species of these tailless amphibians, or Anura. They are also called Salientia,
including the frog and the toad.
Amphibians and reptiles together may be
considered as a group called Herps, therefore, the study of amphibians and reptiles is
called herpetology. The root word, Herp, is from the Greek basically meaning "creepy
crawly things that move about on their bellies.
"
A group of frogs is called an
"army."
MYTHS
Some Australian abortiginees and American
Indians believe that frogs were the bringers of rain.
In India, frogs were felt to represent
thunder in the sky. In Sanskrit, the word for "frog" also meant
"cloud."
In the country of China, instead of the
"man in the moon," they see the "toad in the moon." The toad is
considered one of the five "poisons of yin.
" Eclipses occur when the "toad
in the moon" tries to swallow the moon itself.
To the Japanese, frogs are symbols of good
luck. One myth is that bullfrogs are descended froma great ancestor who could suck
mosquitoes out of a whole room in a single breath.
Folklore has suggested that if the first
frog you see in the string is sitting on dry land, you will shed as many tears as the frog
would require to swim away. If the frog jumps into the water, that is even worse. You will
experience a year of misfortune.
A frog jumping toward you will signify that you will have
many friends, but if it is jumping away, you will lose some.
To some unenlightened people, frogs and
toads, mainly the latter, are evil incarnations of demons and devils.
Warts, as opposed to myth, are the result
of viruses, not frogs and toads.
Batrachophobia-Fear of amphibians, such as
frogs, newts, salamanders, etc. Ranidaphobia-Fear of frogs Bufonophobia-Fear of toads
FROG ENEMIES
Frogs have multiple enemies, including
snakes, birds, and small animals like hedgehogs. Even other frogs can be enemies.
The
worst frog enemy is probably pollution, and frogs and important in measuring the health of
the environment and in tracking ultra-violet radiation penetrating our atmosphere.
Worldwide, frogs numbers have been diminishing, with many species nearing extinction.
FROGS and TOADS
All toads are frogs, but not the opposite.
Frogs, to our common understanding, are the more than 400 species of the family Ranidae.
They have 1) two bulging eyes 2) strong, long, webbed feet that are adapted for swimming
and leaping 3) smoothe or slimy skin (frogs tend to like moister environments and 4) tend
to lay eggs in clusters. They can be found on every continent except Antarctica.
Toads are members of the family Bufonidae,
with more than 300 species. They have 1) Stubby bodies with short hind legs (for walking
rather than hopping 2) Warty or dry skin (toads prefer dryer climates) 3) Paratoid (or
poison) glands behind the eyes 4) Chest cartilage different from frogs 5) tend to lay eggs
in long chains, although there are toads of the Nectophrynoides genera which bear live
young. They can be found worldwide except for Australia, the polar regions, Madagascar,
and Polynesia.
LIFE CYCLE OF THE FROG
Mating occurs by the male frog climbing on
the female's back and grasping her "around the waist" in an embrace called
amplexus. Amplexus may actually last up to several days. As the female lays her eggs, the
male frog fertilizes them.
Many, many eggs are laid, because most of
the time, they will never survive. As the yolk divides and divides, something that
resembles a tadpole begins to develop in the egg. After about 6 days, the egg hatches. The
tadpole initially feeds on the residual yolk, which is actually in its gut. The tadpole is
really fully developed. It usually attaches itself to floating weeds and grasses.
It is
not until 10-12 days later that it begins to feed on algae.
After about 4 weeks pass, the gills are
gradually grown over by skin, eventually disappering. They develop very tiny teeth which
help them grate food, turning it into soupy oxygenated particles. At 6-9 weeks, little
legs start to appear. The head becomes more distinct and the body elongates. Dead insects
and plants are added to algae as part of their diet.
The arms begin to bulge out and
appear, elbows first. At 9 weeks, the tadpole begins to look like a frog with a tail.
By 12 weeks, the tail has regressed. The
frog grows from about 12-16 weeks they are full-fledged adults. (In some colder places,
the tadpole stage may last throughout the winter.)
FEEDING
Some frogs have sticky tongues which can be
used to catch bugs, "flipping" from the mouth.
Toads usually sneak up on their
prey, and "snap" at it. When a frog swallows a meal, his bulgy eyeballs actually
close and go down into his head, helping to apply pressure to push the meal down the
frog's throat.
HEARING and VOCALIZATION
Frogs hear using big round ears on the
sides of their head called a typanum. It's size and the distance between them depends on
the wavelength of the male frog's call. The frog's ears are connected to their lung, so
when they hear noises, not only does the eardrum vibrate, but also the lungs. Many
scientists believe that this is what keeps the frog from "blowing out its own
eardrums" with its loud calls.
Frogs vocalize by shutting their nostrils
and mouths and squeezing their lungs, expanding their vocal pouches as a resonating
chamber by air flowing over the vocal chords. Large frogs have deep, low frequency voices.
Small frogs have high, chirping (high frequency) voices. In the cold, the frogs repeat
their calls more slowly because the muscles controlling the sounds slow down.
What is a frog's sound in
various languages?
Afrikaans: kwaak-kwaak Arabic (Algeria):
gar gar Catalan: cruá-cruá Chinese (Mandarin): guo guo Dutch: kwak kwak English (USA):
ribbit English (GB): croak Finnish: kvak kvak French: coa-coa German: quaak, quaak Hebrew:
kwa kwa Hungarian: bre-ke-ke Italian: cra cra Japanese: kerokero Korean: gae-gool-gae-gool
Russian: kva-kva Spanish (Spain): cruá-cruá Spanish (Argentina): berp Spanish (Peru):
croac, croac Swedish: kvack Thai: ob ob (with high tone) Turkish: vrak vrak Ukranian:
kwa-kwa
FROG FEET
Frogs have feet that are adaptable to their
habitat. Tree frogs have sucker-like adhesive disks or "sticky pads.
" Frogs
which swim have webbing between their toes. Frogs that burrow into the sand to keep moist
in the heat have stubby, clawlike fingers. Frogs which "fly" have parachute-like
webbing which can act as an air brake when jumping from tree to tree.
LIFESPAN
In captivity, most frogs live between 4 and
15 years. Little is known about their lifespan in nature. Here are some lifespans in
captivity.
Longest lifespan: European Common Toad-40
years Giant Toad: 7-24 years Green and Black Poison Dart Frog: 7-17 years Oriental
Fire-bellied Toad: 11-14 years Ornate Horned Frog: 5-12 years
THE BIGGEST AND THE SMALLEST
The biggest frog is the Goliath frog, found
in Cameron in West Africa. Their bodies can reach 1 foot long (and their legs are at least
that length). It weighs as much as a large housecat, about 3.3kg.
The smallest frog is the Gold Frog or
Brazilian. The adult measures 9.
8 millimeters in body length (with legs drawn in).
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