Page 43 - Amphibian

EARLY DAYS FOR A NEWT EMBRYO Feathery gill
2 At first, the egg divides like a frog’s NEWLY HATCHED
egg – into two, then four, then eight 3 TO EIGHT WEEKS
cells, and so on, until a berrylike Newt larvae
cluster of cells forms. After a have large eyes
week or so, an embryo with a and usually feed
recognizable head, tail, and on water fleas
limb buds takes shape (left). and bloodworms.
Development is rapid, and the They have three pairs
egg hatches after only about of feathery gills, unlike
three weeks. frog tadpoles which have
only two (pp. 38–39). Also,
newt larvaes’ front legs
develop first; frog
tadpoles form their
One of three hind legs first.
pairs of
Newt Internal feathery
larva organs and gut gills
visible through
transparent skin
Typical
large
eye

EIGHT WEEKS AND AFTER
Long, 4The body lengthens, the tail
Eight-week-old spindly grows stronger, and the body
newt larva front leg outline begins to take shape. The
back legs are much smaller than
the long, spindly front legs. As
development continues, the
larva’s head, mouth, body, legs,
Smaller and tail take on a more adult
back leg shape. Some amphibians, such as
axolotls (pp. 12–13), never
develop beyond the larval stage.

Young tiger
salamander with Remains
few gills remaining of gills

Young tiger
salamander’s
tail is almost
same length as
its body Feathery
gill

YOUNG TIGERS
Young tiger Tiger salamander larvae are large – 0.5 in (1.25 cm)
salamander long when they hatch and 4 in (10 cm) long when
with full gills they develop into young adults 12 weeks later.
These two young tigers show the change from a
gilled larva (left) to a nearly transformed juvenile
with tiny gill remnants (above). A young
salamander will eat almost any food it can get into
its mouth (pp. 18–19), a habit that continues
during its life. This is why it is so large – up to
1.5 in (4 cm) longer than a Pacific giant salamander.

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