A tortoise sports a defaced shell at the Turtle Conservancy's Behler Chelonian Center in California. The shells are branded to reduce their value on the black market, and the permanent marking also makes it easier for law enforcement authorities to trace them. Photo: Al Seib/ Los Angeles Times/MCT

LOS ANGELES - A rare tortoise can sell for a lot of money nowadays. Tortoises are reptiles that live on land. They are related to turtles. Unlike turtles, tortoises don't usually swim.

People are trying to protect the rare turtles and tortoises. They are marking the rarest turtles on Earth. The marks make it harder to buy and sell them.

Paul Gibbons gently placed a turtle on a table. He picked up a tool. Then he carved a code into the tortoise's shell.

The letters and numbers are 2 inches high and read "7001 MG." They can never be erased. They will last the tortoise's whole life. A tortoise can live 160 years.

One Of The Rarest

"It's heartbreaking that it's come to this. But it's the right thing to do," Gibbons said. He is in charge of the Turtle Conservancy in California. A conservancy saves animals from dying out.

"We've (spoiled) her natural beauty," Gibbons said.

The ploughshare tortoise is one of the rarest tortoises on Earth. It is against the law to buy and sell them. The Conservancy wants to mark all 360 ploughshares in the world.

So far, the marking program is working. No marked turtle has turned up in markets where rare animals are sold. These markets break the law by selling rare animals.

Many turtles are close to dying out. For many years, they have been hunted. Also, their natural home is being destroyed. Some people want turtles because they are beautiful and rare. Other people think turtles cure diseases. People will pay thousands of dollars for the rarest turtles.

A Secret Hideout

The Conservancy got the ploughshare tortoises in 2008. In November, the tortoise called "7001 MG" laid five eggs. These are the first ploughshare eggs ever laid in a protected program.

People want to steal the tortoises. So, the Conservancy is not open to the public. Its location is a secret. The only visitors are scientists from around the world.

Christine Light works for the Conservancy. It is her job to care for the turtle eggs.

"This little fella hatched on Monday," Light said. She held up an Indian spotted turtle. It was about the size of a large coin. "Too cute for words, right?"

Last year, the Conservancy had 294 baby turtles, Light added. She smiled. "Each one of (them) was a little win for our side."