Page 42 - Amphibian

Early days

Developing
embryo
Like frogs and toads, newts, salamanders, and
caecilians undergo a metamorphosis, or period of Female
larval development. But the change in crested newt
their body shape is less marked. In
newts and salamanders, the larva
looks more like the adult. The
development of the crested
newt is typical of species
with aquatic larvae. Egg, previously
However, many wrapped in leaf that
salamanders do not have has opened, will become
part of food chain
a free-living larval stage.
Instead, the female
salamander may lay her
eggs on land to be guarded
by either parent, or she may
keep the eggs in her body
(pp. 36–37). In each case,
the salamander’s egg and
larval development is the
same as that of the newt but
takes place inside either the
egg capsule or the female’s
body. In caecilians, the
species with free-living
larvae have large gills and,
like the adults, are limbless. Female uses her
feet to wrap
newly laid egg in
leaf of waterweed

Newly
laid egg

CAREFUL MOTHERS
1 This female newt is
using her feet to wrap water-
weed carefully around every
egg she lays. Egg wrapping is a
simple way of protecting the
eggs (pp. 36–37) and is much
EGG SANDWICH safer than leaving them exposed
Newts lay their eggs in open water. Females of some
singly. The female other newts (pp. 46–49) – such as
immediately wraps a those of eastern North America
waterweed leaf around and the fire-bellied newts of the
each egg to hide it from Far East – show this egg-wrapping
predators, and so it has a behavior. They lay between 200
greater chance of hatching. and 400 eggs in this way.
This leaf has opened,
exposing the white egg, which
probably will be eaten by a
passing fish.

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