They rely more on stealth for protection and hunting than
their hard-shelled brethren. They will lie, covered in sand
with just their snout sticking out of the substrate, as both
a protective and ambush method. It has some curious adaptations,
including a capacity for aquatic "breathing". If
quietly submerged, this turtle can absorb 70% of its oxygen
requirements through its skin, thus spending long periods
without having to surface to breathe.
When
it does come up, the waterside watcher is unlikely to see
much of it, for its snout is bizarrely elongated into a pair
of little snorkel-like tubes, which, coupled with its long
neck, are an adaptation to breathing without having to expose
too much of itself or bring its body too near the surface.
Feeding
Nile soft-shelled turtles are mainly carnivorous (meat-eaters) but
eat a range of food from fish, snails and some aquatic insects,
crustaceans, amphibians and reptiles. They also eat palm nuts, dates
and apparently even recorded eating a goat carcuss! Captives feed
on frog meat and raw and slightly boiled liver
They
will lie covered in sand with only their snout sticking out, this
is for protection and to ambush their prey when it comes within
reach. It’s long neck is used in hunting to seize prey in
a sudden darting stab, as well as in mating.
Courtship
and mating
Little is known about courtship or mating of this secretive species,
except that in courtship- the amorous male lovingly bites the female’s
neck.
Nesting
Nesting occurs from March to July, depending on latitude; nesting
in Turkey occurs from early June to late July. Most nest cavities
are dug in sand and earthen banks and on islands close to the shore
(5-15 m). Those living in brackish coastal waters may lay on adjacent
sea beaches. A nest measured in Turkey had a diameter of 15-20 cm
and a depth of 20-25 cm.
Nests
are dug in banks along the river, or, for the ones closer to sea,
on the sandy beaches. Sometimes, when it does not find suitable
nesting sites along the banks of the rivers, it uses sandy beaches
close to river mouths, and thus sometimes nests at the same places
as Loggerhead and Green Turtles.
Eggs
and Hatchlings
Several clutches may be produced per season. The white brittle-shelled
eggs are spherical, about 32 mm in diameter; Reports of a mean of
35.3 mm (34.4-36.3) for 31 eggs in Turkey. A single female may contain
25 to more than 100 eggs, although in a study by (Atatür, 1979).
only found 8-34 eggs in three nests. Incubation in the laboratory
took about 56-58 days.
Hatchlings
are 42-54 mm long, and weigh 8-17 g. They are greenish brown with
numerous, conspicuous yellow spots with thin brown-black peripheral
rings. With age, the ground color becomes darker and the light spots
become smaller and more numerous.
Commensuals
and Disease
Little
is known about any diseases afflicting the Nile soft-shelled turtle.
Sources:
Kasparek,
M. (2001). Towards an Action Plan for the Conservation of the Nile
soft-shelled turtle, Trionyx triunguis in the Mediterranean. MEDASSET:
www.medasset.org/PDF/coe01_trionyx_mkasparek.pdf
Atatür,
M. K. (1979): Investigations on the morphology and osteology, biotope
and distribution in Anatolia of Trionyx triunguis (Reptilia, Testudines),
with some observations on its biology [in Turkish]. . Ege Üniv.
Fen Fak. Monograf., Izmir, Ser. no. 18: 1.75.
