Page 9 - Amphibian

What is not an amphibian?

This tegu lizard from the tropical parts of South
America looks similar to a salamander, such as the Tegu lizard –
fire salamander below, and some snakes, particularly not an
the little worm snakes, look like caecilians, but lizards and amphibian
Skin of snakes are reptiles, not amphibians. Reptiles can easily be told
crested apart from amphibians by their dry, scaly skin. Earth-worms and
newt
caecilians look very similar, but many a biologist has been
startled to see the worm they had picked up open its
mouth to show an impressive set of curved, sharp, little
teeth! Also, some tadpoles look like small fish, but the lack
of scales and body fins shows that
they are quite different.

Skin of orange
striped newt

THE ROUGH AND THE SMOOTH Typical dry,
Typically, newts have smooth, slimy scaly skin
skin and salamanders have dry, warty skin, of reptile
but as with frogs and toads, there are always exceptions.
For example, the fire salamander’s skin (bottom) feels
smooth and damp.
ODD AMPHIBIAN
The body rings on a
caecilian make it look like
a worm, but the
shark-like head and
needlesharp
teeth show it is
no worm! Some
species have tiny,
fishlike scales
within the rings.
About 170 species
are found in tropical
parts of the world.

Fire salamander lives
in forests, but near
water, and ranges in
length from 6–13 in
(15–32 cm)

Fire salamander’s
smooth, damp
skin is typical of
many amphibians
ANCESTRAL SHAPE
Newts and salamanders (pp. 46–49) are more like the early ancestral
amphibians than either the more distinctive frogs and toads or the
caecilians – the overall body shape has remained basically the same
(pp. 8–9). The head is narrow and has small eyes and a smaller mouth
than in frogs and toads; the body is long and lizard-shaped; and there
is always a well-developed tail. Their four legs are all similar in size and
length, so they walk slowly to moderately fast and catch slow-moving
insects and earthworms for their food (pp. 18–19).