Thomson S.¹, Kennett R.² and Georges A.¹ (2000). A new species of long necked turtle (Chelidae:Chelodina) from the sandstone plateau of Arnhem Land, Northern Australia. Chelonian Conservation and Biology 3:675-685.

1. Applied Ecology Research Group and CRC for Freshwater Ecology, University of Canberra, Canberra, ACT, 2601, Australia.
2. Centre for Indigenous Natural and Cultural Resource Management and Faculty of Science, Northern Territory University, Darwin, NT 0909, Australia

Download PDF Version      

Abstract:--A new species of long-necked freshwater turtle of the family Chelidae is described from the Arnhem Land Plateau in the Northern Territory of Australia. The taxon is within the Chelodina expansa group of species and is the smallest member of that group. First collected by scientists some 20 years ago, research on the species has been hampered by its isolation – it is restricted to sparsely inhabited, rugged sandstone country of tropical northern Australia. It can be diagnosed by its broad, shortened and flattened skull, by the possession of a contiguous neural series and by the contact of the vomer and the pterygoids. It is clearly distinct from Chelodina rugosa in a canonical discriminant analysis. Preliminary data on natural history are also presented. Males examined in October-November had enlarged vascularised testes and epididymes distended with sperm. Females examined at the same time had regressed corpora lutea and atretic follicles from the previous nesting season, presumably in the immediately preceding dry season. The diet is primarily fish and shrimp, but unlike other Chelodina which are all obligate carnivores, this species appears to feed on both plant and animal material. The turtle is well known to Aboriginal people of the region who collect it for food, and they report that it consumes leaves and fruits of aquatic and riparian vegetation and reproduces in the dry season.

Keywords.-- Reptilia; Testudines; Chelidae; Chelodina burrungandjii sp. nov., turtle; taxonomy; ecology; diet; reproduction; habitat; indigenous knowledge; conservation; Australia

Introduction  

     Conservation of Australia’s freshwater turtle fauna is hampered by poor taxonomy at the species level. Many distinct forms, known to science for many decades, have remained undescribed. Formal recognition and data on distribution and abundance are often essential prerequisites for marshalling government support for conservation (Georges, 1993). These undescribed forms have been largely ignored in the action plans and recovery plans that govern the threatened species initiatives in Australia. However, there has been recent progress. The Mary River Turtle Elusor macrurus (Cann and Legler, 1994), known to science for 20 years only as specimens of unknown origin in the pet trade, the White-eyed River Diver Rheodytes leukops (Legler and Cann, 1980), the ‘living fossil’ Elseya lavarackorum from the Nicholson drainage of Queensland (Thomson et al., 1997), the Bellingen River Turtle Elseya georgesi (Cann, 1998a), the Northern Yellow-faced Turtle Emydura tanybaraga (Cann, 1998b) and the Yellow-headed Snapping Turtle Elseya irwini (Cann, 1998c) are all recent additions, and testimony to the advancing state of our knowledge of this group. Electrophoretic surveys (Georges and Adams, 1992, 1996) indicate that there are many more distinct forms awaiting formal description, lending support to earlier indications based on morphology (Cann, 1978; Legler 1981).

In particular, a new form of turtle from the Arnhem Land Plateau first came to the attention of science when collected during surveys of the Arnhem Land region in the early 1970’s. Aboriginal people in the region are familiar with the turtle and have hunted it for food and ceremonial purposes for generations. The Gagadju people of Kakadu National Park recognise it as a distinct form in their language, referring to it as Burrungandji. They distinguish it from Almangiyi (Chelodina rugosa), a common and closely-related species of the coastal floodplains (Lucas and Russel-Smith, 1993). The Jawoyn people of the Katherine region (including Nitmiluk National Park and the southern sections of Kakadu National Park) refer to it as Wurruyung (Sandy Barraway, pers. comm.), but this name is used also to refer to C. rugosa.

Legler (1982) too, in an unpublished report, recognized the form as a new species, and its status as a distinct taxon was later confirmed by electrophoretic comparisons (Georges and Adams 1992; Georges et al., in prep.), but it has remained unnamed. In this paper, we describe this new species of long-necked turtle of the genus Chelodina (Fig. 1), and provide some information on its natural history and ecology.

     Turtles representing all known species of Chelodina from Australia and New Guinea were obtained from museums and private collections. Additional specimens were collected directly from the field, examined and measured, and either retained for skeletal preparations or marked and released at their point of capture. Data on colouration are therefore based on examination of both live animals in the field and museum specimens. The measurements routinely taken are described in Appendix A. Skeletal preparations were was made using methods outlined in Thomson et al. (1997). Skeletal terminology and description follows that of Gaffney (1979) for skulls and Zangerl (1969) for shells.

All means are presented with their standard errors, not standard deviations, unless otherwise specified. Discriminant analysis (SAS Institute, 1988) was used to determine how well external measurements of head and shell could distinguish among the Chelodina species, and the new species described here and its closest relatives in particular.

     For the ecological studies specimens were collected by diving with mask and fins and trapping in baited traps at the Gunyarr pools adjacent to the Katherine River Gorge in Nitmiluk National Park (133o 31’ 10”E 14o 18’30”S) on 23-24 August 1996 and 24-25 October 1996, and in a section of the upper Katherine River (133o 05’E 13o 46’S) on 4-6 November 1996. A total of 22 specimens (12 females, 7 males, 2 juveniles, :1 sex not recorded) were captured at Gunyarr pools and 10 specimens (5 females, 4 males, 1 juvenile) in the upper Katherine River. Of these, 11 females and 8 males were examined via laparoscope to determine sex, reproductive status and body condition. Males with enlarged vascularised testes and epididymes that were white, coiled and distended with sperm (Kennett, 1994) were judged as mature. All such mature specimens had longer thicker tails than females of the same size (c.f. Chelodina rugosa, Kennett, 1994; 1996). Females with thickened, muscular oviducts, or ovaries with enlarged vitellogenic follicles or corpora lutea, were judged as mature.

Stomach samples were collected from 30 turtles (16 females, 11 males, 2 juveniles, 1 sex not recorded) by stomach flushing within 2 hours (usually sooner) of capture. A steady flow of water supplied by a submersible electric pump was passed into the stomach through a flexible plastic tube with the turtle held in horizontal position (after Georges et al., 1986). The turtle was then inverted and water flowed out of the esophagus and mouth carrying the stomach contents with it. Stomach contents were preserved in 70% alcohol and later examined under a stereoscopic microscope.

Type specimens.—Holotype: NTM 16010 (UC Blood Ref: 0316) Adult female collected by Rod Kennett in Koolpin Gorge, South Alligator River (Lat: 13 deg 28 min S, Long: 132 deg 38 min E) on 6 Sept, 1989 (Figure 2a.). Allotype: NTM 16011 (UC Blood Ref: 0317) adult male with same data as the holotype (Figure 2b.) See Table 1 for comparative measurements).

Referred Specimens.—NTM 13525, 16008-12, 16333, 22581-83; UC 2088-90, 2101; UU 17730-31, 17732, 17733-34, 17735, 17736, 17737, 18833, 18834-39, 18840-41, 18842-52, 18853-58, 18859.

Navigation:    Page 1    Page 2    Page 3    Page 4    Page 5    Page 6