The word amphibian means two-
lives. Amphibians spend their lives
in the water and on land.
There are about 6,000 known species of frogs,
toads, salamanders, and caecilians.
Frogs and toads are the most diverse, with
about 29 families and 4,380 species.
Caecilians: a wormlike
tropical amphibian, it
spends most of its life
underground and usually
Frogs lay their eggs in water.
After some time, the baby frogs develop a tail. They are called tadpoles. After a
few days, the tadpole can swim around and eat algae.
It develops tiny legs and it begins to look more like an adult frog. After a few
weeks, the tail disappears completely. Adult frogs live in a colony of frogs. They
mate and return to the water to lay eggs.
Metamorphosis Tadpole: the limbless aquatic
larva of a frog or toad, it has
gills and a long flat tail. As the
tadpole approaches the adult
stage, legs and lungs develop,
and the tail gradually
The first amphibians appeared approximately
370 million years ago during the Devonian Period.
The earliest fossil amphibian is considered to be
Ichthyostega, an animal that had four limbs and
Limb: a part or
member of an
animal body distinct
from the head and
trunk, as a leg, arm,
Devonian: pertaining to a
period of the Paleozoic
Era, 405 to 345 million
years ago, characterized
by the dominance of
There are five different kinds of
amphibians: frogs, toads,
salamanders, newts and caecilians.
Newt: any of several
salamanders, it lives in
Europe, and northern
Salamander: any tailed
amphibian, they have a soft
and moist skin, typically aquatic
as a larva and terrestrial as an
adult: several species are
Every species of amphibian
is unique, colorful, and
these creatures are in
serious trouble all over the
world. Many amphibians
have already gone extinct
and hundreds of species,
The axolotl is endangered because of the draining of
its habitat. They live only in Mexico. Sometimes,
they are sold as pets, but those are wild animals.
Axolotl: any of several
salamanders of the genus
Ambystoma that inhabit
lakes and ponds of Mexico
and remain in the larval
stage as mature adults.
Small amphibians feed small insects and
worms. Larger amphibians feed larger
insects and invertebrates. Very large
species such as the Bullfrog and Giant
Salamander eat snakes, shrews, mice, fish
and other amphibians.
Amphibians are a very important control of many species we consider pests,
especially insects. Most of amphibians can catch away a lot of insects at one time.
Pests: an insect or
other small animal
that harms or
plants, trees, etc.
Frogs and toads are also great singers. Like birds, they sing for several reasons.
The first is to attract a mate. Male frogs and toads gather sometimes in large groups
in and around a pond. In both the early morning and evening, they will sing to attract
member of a pair
Gather: to be
one group or
Scientists are discovering that many amphibians have
features that could be helpful to people. The special skin
of amphibians produce all kinds of unusual chemicals,
and some of those chemicals can fight diseases that hurt
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