T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Turtle (Eastern long-necked) Chelodina longicollis

Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Order: Chelonia
Suborder: Pleurodira
Family: Chelidae
Subfamily: Chelodininae
Genus: Chelodina
Subgenus: Chelodina
Species: C. longicollis
Binomial name: Chelodina longicollis
Synonyms: Testudo longicollis, Chelodina novaehollandiae, Chelodina sulcata Gray, Chelodina sulcifera
Common names: Eastern long-necked turtle, Eastern snake-necked turtle, Stinker.

Chelodina longicollis is an east Australian species of side-necked turtle (Pleurodire), meaning that it bends its head sideways into its shell rather than pulling it directly back. The species is found throughout south-eastern Australia. 
They are kept as pets in New Zealand and can they be a pest problem when released into the wild.

The Northland Regional Council’s website states
“Why is it a problem? This species is a generalist feeder, consuming fish, tadpoles, hatchling turtles, worms, crickets, etc. if left uncontrolled and high numbers occur in a particular area, this can have negative effects on the water quality of a stream or river, as vital components of the food chain/environment are missing as a result. This can present itself in the form of poor water quality, which in turn further impacts native species while also making a stream or river unsuitable for use.”
New Zealand environment meets the minimum thermal requirements for the incubation of eggs of the snake-neck turtles (Chelodina longicollis), 

Chelodina longicollis is a medium sized turtle that averages 25 cm in length. They have a light brown to a black oval shell, with a shallow groove in the middle. The underside of the shell is cream-coloured with dark seams, their necks are long and narrow, with a brown to a grey upper surface and yellow underneath.
When stalking prey they wind their long necks back, striking like a snake once they're close.
When it feels threatened, this turtle will emit an offensive smelling fluid from its musk glands near their groin. This trait gives the turtle one of its other common names, "stinker".

A video by the Auckland Zoo on the Eastern long-necked turtle

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/