Endangered tortoise stolen from Perth Zoo

Perth Zoo holds grave fears for a critically endangered radiated tortoise that has been stolen, possibly for trade on the black market.

A supplied image obtained Thursday, Feb. 4, 2016 of a critically endangered radiator tortoise, highly prized on the black market. Source: AAP

A critically endangered tortoise, highly prized on the black market, has been stolen from Perth Zoo.

Staff believe the 10-year-old radiated tortoise was taken on Monday night or early Tuesday morning.

"They're highly prized on the black market. A lot of the individuals that we have here have come to us via wildlife seizures at customs or international borders, taken from smugglers," a Perth Zoo spokeswoman told AAP.

Perth Zoo life sciences director Maria Finnigan said she held grave concerns for the tortoise, as they were often killed for their shells, which are turned into ornaments.

"This is an extremely rare tortoise and in danger of extinction," Ms Finnigan said.

The tortoise, native to Madagascar, is a sub-adult and about 15cm in diameter, Ms Finnigan says.

"This species have a specialised diet and like all tortoises it needs help thermo regulating, which is especially important at the moment as we are experiencing cooler mornings," she said.