Friday, 20 July 2012

Turtles 9: New Arrival

Just gone on show in one of the pools in the Reptile House is one of the rarest and most endangered of all turtles, the Roti Island Snake-Necked Turtle, Chelodina mccordi. Originating from an island near New Guinea, it was only split from the more widespread New Guinea Snake-Necked Turtle in 1994. Sadly, collection for the international pet trade for this endemic species has placed it on the Critically Endangered list, and today it is only known from a few sites on the island with a total area of 70km2.

These highly aquatic turtles frequent ponds and rice paddies with a lot of marginal vegetation, which provides shelter for their prey. They are highly predatory, feeding on aquatic invertebrates and small fish, and their long, sinuous necks probably help them to investigate tangled vegetation while remaining in clearer water which provides a better escape route. The only time they leave the water is to lay eggs, which in larger females may be as many as 14 in a clutch, and they can produce several clutches a year. With a high reproductive rate, they probably have numerous predators – larger fish, herons, monitor lizards and probably freshwater crabs as well must find the hatchlings an easy meal. When full grown they can measure up to 28cm long shell length, but at all times the neck is as long as the carapace, giving them the appearance of a miniature plesiosaur.

The ancestry of the snake-necked turtles is an ancient one. They belong to an ancient family called the Chelidae, which dates back to the Cretaceous. It originated in Gondawana, the ancient supercontinent which included all the southern continents of today, including Antarctica. In Africa however the group died out, and today Chelid turtles are found only in South America and Australasia. Most of the other species have a larger range, and most of the Roti Island Snake-Necked Turtle’s closest relatives are classed as Least Concern.

There are several species of Chelodina that can be seen in zoos around the world, and quite a few of various species in private hands. If any reader of this blog has one and is not sure which species they have, please get it identified – if it is a Roti Island turtle every effort should be made to include it in the captive breeding programme. The latest information I have been able to find indicates that it may already be extinct in the wild, or reduced to such small numbers that the population may never recover.

For a video of a live Roti island Turtle, see here:

Further reading:

For a study on captive Roti Island Snake-Necked Turtles see here:

For a husbandry manual, including veterinary advice, on a related species of snake-neckedturtle, see here:

(image from wikipedia)

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