[HOME] HOW
TO CARE FOR AUSTRALIAN FRESHWATER TORTOISES
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2 DESCRIPTIONS
Australian native tortoises belong to a sub-order called Pleurodira.
Pleurodires are side-necked tortoises; that is, when they withdraw
their head for protection, they bend their neck sideways. Pleurodires
are only found in the southern hemisphere. They are a more ancient
form of tortoise than the Cryptodires, which are common in the
northern hemisphere. Cryptodires withdraw their heads straight
back into the shell by flexing their necks in a vertical "S"
shape. Even before the Pleuiodires there was a sub-order of
tortoises called Proganochelys. They are now extinct. They were
unable to withdraw their head and neck.
Australian tortoises belong to the family Chelidae.They are
all aquatic tortoises and may be split into two groups : long-necked
and short-necked tortoises. The two species most commonly sold
as pets are from each of these two groups. The scientific name
of the short-necked species is Elseya latisternum. They are
also known as the saw-shelled snappers. These tortoises
were named after Dr J.R. Elsey who found the first specimen
in 1855-56. They usually come from northern New South Wales
and Queensland. The name of the long-necked species is Chelodina
longicollis, or snake-necked tortoise; they frequently
come from South Australia and the Murray River. "Longicollis
means "long-necked". The Murray short-necked tortoise,
Emydura macquari, is also frequently kept as a pet.
The upper half of a tortoise's shell is called the carapace.
The underneath half is called the plastron.
Snake-necked tortoises
The carapace of Chelodina longicollis babies is gently curved,
almost flat. There is no hump or ridge. It is dark brown to
black in colour. The skin is black. There are vivid orange markings
on the underside of the edges of the carapace on either side
of the head and along the edges of the plastron, which disappear
as the youngsters grow older. These markings are most attractive.
Both species have webbed feet. Short-necked tortoises have five
claws on the front feet and four on the hind feet. Long-necked
tortoises have four claws on all feet. Both kinds have tiny
tails.
The head and neck of long-necked tortoises are about as long
as or longer than the carapace when they are babies. But when
they are mature the average length of head and neck would be
about 70 per cent of the carapace length. |
