An unresponsive dolphin found in the waters off the Village of North Haven in Southampton earlier this week was underweight and had oral lacerations that probably limited its feeding and caused its emaciated condition, a marine environmental group said Thursday.

The Riverhead Foundation for Marine Research and Preservation had euthanized the 600-pound male Risso's dolphin after it was spotted Tuesday afternoon.

A necropsy showed the dolphin had been in poor health for an extended period, the foundation said. The dolphin had parasites and tapeworms, missing teeth, infected gums and congested lungs, the group said.

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"There was no sign of recent feeding within the gastrointestinal tract," the foundation said in a statement. "The dolphin was 100 pounds underweight, and likely not eating due to the painful oral lacerations."

Risso's dolphins are typically found further offshore and there are about 13,000 to 20,500 in the western North Atlantic, according to the National Marine Fisheries Service's Office of Protected Resources.