Most amphibians begin life in water breathing
with gills and then venture onto land as adults,
where they breathe using lungs and through
their skin. They live in damp
places, and most return
to the water to breed.
There are three groups
of amphibian: frogs
and toads, newts and
salamanders, and caecilians.
Gills, lungs, and skin
Some salamanders spend their whole lives
in water and may keep their tadpole gills
even as adults (although they do have
lungs as well). Others live entirely on
land, where some manage without lungs.
They absorb oxygen directly into their
bloodstream through their thin skin.
Keeping the skin moist helps the oxygen
pass through.Amphibians
FAST FACTSFROM EGG TO ADULT
1. SPAWN
Frog and toad eggs
are laid in clusters
or strings protected
by a special jelly. POISON! Amphibians have
glands in their skin that ooze
toxins. The foul taste deters
potential predators and may kill
them. Some tree frog toxins are used
to make deadly poison-tipped darts.O There are around 6,000 amphibian species.
O Amphibians are cold-blooded, and have
no hair or scales.
O Most adult amphibians are carnivorous,
eating insects, worms, and even birds and
snakes. Tadpoles start life as vegetarians.
O All amphibians lay eggs. Some lay just
one or two eggs at a time, but others can
lay up to 50,000. 3. FROGLET
The tadpole first grows
back legs, then front
limbs. The tail begins
to shrink until the
youngster resembles
a tiny version of
the adult. 2. TADPOLE This young
tadpole has yet to develop
external gills. The gills become
internal as the limbs develop. 4. FROG
The adult lives
mostly on land but
is also happy in
water. It breathes
using lungs and
through its skin.100 GLASS FROG—Frogs have
delicate skin. A glass frog’s skin lacks strong
pigment and is almost transparent.Young amphibians such as this frog hatch
as larvae (tadpoles) that look nothing like
their parents. The series of changes that
take place as a larva grows into an
adult is called metamorphosis.LIVING WORLD
Bright colors
warn predators