Historical Papers
Dorrian, C., 1994, Captive Management of Carettochelys insculpta, Herpetofauna, 24(1):15-18
Comment: This is the firt paper published on captive management of Carettochelys insculpta. Jan Matiaska (2004).
CAPTIVE MANAGEMENT OF THE PIG-NOSED
TURTLE,
CARETTOCHELYS INSCULPTA
Chris Dorian
Taronga Zoo, P.O. Box 20, Mosman, 2088
ABSTRACT
Until now nothing has been published on the requirements or behaviour in captivity of Carettochelys insculpta. The Reptile Department of Taronga Zoo has successfully maintained a small number of these animals since 1989. Studies on their interactive behaviour showed that the Pig-nosed turtle will not peacefully co-exist with members of its own species in a captive environment.
Tests were conducted with two animals being placed into a glass tank divided in half by a clear perspex sheet. Whenever the larger turtle became visually aware of the second animal, it would swim quickly toward it, mouth agape before colliding with the divide, and would bite at the divide until the smaller animal moved out of sight.
When introduced into a large communal tank, the same aggressive behaviour was observed toward individuals of its own species, but not towards or from, Chelodina expansa, Ch. longicollis, Emydura krefftii or Elseya latisternum. A sympatric species, Chelodina rugosa, attacked each member of C. insculpta, biting at the head and flippers, whenever visual contact was established.
The animals are fed an undemanding omnivorous diet. Each shows a distinct individual preference for certain vegetation, and all favour an herbivorous rather than a carnivorous diet.
INTRODUCTION
Carettochelys insculpta is a morphologically distinct species of freshwater turtle. The limbs are modified as flippers, and like marine turtles the swimming action enables the pig-nosed turtle to quite literally fly through the water. It is also the only Cryptodire turtle native to Australia, all others belong to the infraorder Pleorodira which are side-necked turtles. C. insculpta is related to the soft-shelled turtles of the family Trionychidae (Ernst & Barbour, 1989). The formerly widespread family of Carettochelyidae is today represented by only one extant species restricted to southern New Guinea and northern Australia. Commonly known as the pig-nosed, pitted-shell or Warradjan Turtle, the species has been well documented since its discovery in this country. The research and subsequent publications, however, have dealt almost exclusively with wild populations. Literature regarding husbandry techniques in keeping these animals in a captive environment appears to be non-existent.
BACKGROUND
C. insculpta was described in 1886 by Dr E.P. Ramsay from a single specimen. This being one of two turtles collected from the Fly River in New Guinea by explorers W. Froggat and J.H. Shaw.
The first report of the pig-nosed turtle being resident in Australia was 1969, when a single specimen was caught on a fishing line from the Daly River in the Northern Territory. A photograph of this animal was sent to Dr Harold Cogger at the Australian Museum who requested further specimens and an additional nine turtles were subsequently caught and measured. The smallest, a sub-adult with a carapace length of 265mm, was forwarded live to Dr Cogger and was housed at Taronga Zoo. The existence of Carettochelys insculpta was still not widely known until the publication of scientific literature (Cogger, 1970; Peters, 1970).
Populations have also been located in Northern Australia in several rivers of the Victoria and Alligator River systems (Cogger, 1992). Cann (1978) considered additional populations probably occur in many rivers along the north coast.
Heaphy (1990) estimated that males in the Daly River reach sexual maturity between 14 and 16 years of age at a size of about 300mm (carapace length) and females between 20 and 22 at 330mm. the lengthening tail of the male may be apparent from 10 years onwards. The largest male observed by her in the Daly River between 1986 and 1988, had a carapace length of 372mm and the largest female a carapace length of 413mm.
Georges and Kennett (1989) report that the largest male observed in Pul Pul billabong, Kakadu National Park, had a carapace length of 454mm and weighed 9.5 kg and the largest female a length of 523mm and weighed 16.0 kg.