3.
4.
‘Neotony has also
been associated with
with human evolution
as we retain
characteristics
typical of immature
primates.’
All of the world’s largest salamanders are neotenic and permanently
retain a fully-aquatic form that differs little from the larvae, if at all.
The Chinese Giant Salamander (Andrias davidianus) is the largest of
all, attaining a maximum size of 180 centimetres and 59 kilograms,
although large specimens are now exceedingly rare. Dubbed the
‘Wawa Yu’ or ‘baby fish’ because of vocalisations that resemble a
human infant, this critically-endangered amphibian prefers fast-
flowing, shallow, rocky streams, typically at altitudes between 300-
800 metres. It has very poor eyesight, but hunts invertebrates,
crustaceans and other amphibians by means of sensing vibrations in
the water.
The closely-related Japanese Giant Salamander (Andrias japonicus),
which can reach a size of 160 centimetres and 25 kilograms, is also
restricted to cool, fast-flowing streams laden with oxygen. Like
A. davidianus, being bereft of external gills, gaseous exchange is
facilitated by cutaneous respiration, and aided by numerous wrinkles
and folds which increase the surface area of the skin. In Japanese,
this species is referred to as the ‘giant pepper fish’ because of its
ability to excrete a milky, peppery-smelling substance as a defence
mechanism.