A man already accused of keeping a collection of wild animals including a river otter and a two-toed sloth has been cited for owning an endangered ape.

Pierce Onthank, the president of an oil and gas company, is charged with illegal possession of a primate for keeping a siamang, a type of gibbon that is native to rain forests in Malaysia and Indonesia and can weigh up to 30 pounds and stand 3 feet high.

Onthank's wife, Susan Onthank, said their 2-year-old siamang, Koby, weighs about 14 pounds and wears diapers. She said her husband would make a statement by Monday, when he's scheduled to be in court for the infraction.

The charge against Onthank, who could face a fine of less than $500, comes a month after a Stamford woman, Charla Nash, was mauled by a 200-pound chimpanzee owned by a friend, Sandra Herold. Nash, 55, is hospitalized at the Cleveland Clinic in Ohio.

The mauling triggered Congress and state officials to consider strengthening laws against keeping exotic animals. A bill proposed by Attorney General Richard Blumenthal and Department of Environmental Protection Commissioner Gina McCarthy would impose penalties of up to one year in prison and a $2,000 fine.

Authorities say Onthank took Koby to the Lionshare Zoological Center in the Greenwich/Stamford area in October while trying to sell his house in nearby Fairfield, where the animal control office had registered 16 incidents involving his dogs and neighbors had complained he had 12 monkeys, a tortoise, large iguanas and an otter.

Lionshare's owner said the pet siamang had very thin hair and dry skin, and a curator there said Onthank also had owned monkeys, lemurs and a two-toed sloth, a court affidavit stated.

The Connecticut Department of Environmental Protection began investigating and learned Onthank never had the required state and federal permits for the ape, the affidavit said.

Onthank, who also is being investigated by federal authorities, has "a history of improper care and control of both exotic and domestic animals," it said. He took a primate to a veterinary office to be treated for pneumonia in 2006, and a dehydrated baby sloth he owned died in 2005, it said.

Onthank, 49, heads Westport-based American Energy Group, an oil and gas drilling company that has interests in Pakistan and Galveston, Texas.