HUTCHINSON ISLAND, Fla. - The body of a melon-headed whale, rarely found in Florida waters, washed ashore this week hours after four others were found dead or had to be euthanized because scientists determined they were too sick to be saved.

The first was found dead Wednesday morning at Vero Beach. The others were discovered on Hutchinson Island later that day, said Steven McCulloch, executive director of marine mammal research and conservation at Harbor Branch Oceanographic Institution.

"It's been kind of a wild goose chase, and we're not sure it's over yet," McCulloch said.

All of the melon-headed whales, also known as electra dolphins, were about 7 to 9 feet long and appeared thin and malnourished, said Greg Bossart, director of marine mammal research and conservation at Harbor Branch, a research facility north of Fort Pierce.

Necropsies showed that the animals had ulcers in their stomachs, a sign of stress, and had not eaten for weeks.