Chelodina oblonga Gray 1841 – Northern Snake-Necked Turtle.

In: Rhodin, A.G.J., Pritchard, P.C.H., van Dijk, P.P., Saumure, R.A., Buhlmann, K.A., Iverson, J.B., and Mittermeier, R.A. (Eds.). Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group. Chelonian Research Monographs No. 5, pp. 077.1–13, doi:10.3854/crm.5.077.oblonga.v1.2014, http://www.iucn-tftsg.org/cbftt/.

Summary:

The Northern Snake-necked Turtle, Chelodina (Macrochelodina) oblonga (Family Chelidae), until very recently known as C. (M.) rugosa, is a fairly large freshwater turtle (carapace length to 360 mm) with a broad distribution in tropical northern Australia and southern New Guinea. Its preferred habitats are seasonal wetlands on the coastal floodplains and adjacent hinterlands. These habitats undergo extensive flooding during the tropical wet season, with declining water levels during the following dry season; many waterholes dry completely. The species survives the dry season by migrating to permanent water or by estivating under the mud of dried waterholes. It is a highly prized food item among Aboriginal people, and turtles are collected each year in a harvest that has occurred for many millennia. The species is exclusively carnivorous and feeds on a range of fast-moving aquatic invertebrates, tadpoles, and fish. It is a highly fecund, fast-growing, and early-maturing species in comparison to most other Australian chelids. Its habit of nesting underwater makes it unique among all turtles. Nesting commences in the wet season (February) and is mostly complete by July (mid-dry season), though gravid females can be found as late as September if waterholes remain inundated. Eggs are laid in holes dug in mud under shallow water in the littoral zone of flooded waterholes. Embryonic development remains arrested while the nest remains flooded, but recommences when floodwaters recede and the ground dries. Embryonic development proceeds during the dry season and hatchling emergence coincides with the heavy rainfall or flooding in the following wet season. The species remains common in all the major river systems across northern Australia and southern New Guinea, and is sustainably harvested for traditional consumption in Australia, but is under some threat there from pig predation.