MANILA, Philippines – Scientists exploring a deep ocean basin in search of species isolated for millions of years found marine life believed to be previously undiscovered, including a tentacled orange worm and an unusual black jellyfish.

Project leader Dr. Larry Madin said yesterday that U.S. and Philippine scientists collected about 100 different specimens in a search in the Celebes Sea south of the Philippines.

Madin, of the Massachusetts-based Woods Hole Oceanographic Institution, said the sea is at the heart of the “coral triangle” bordered by the Philippines, Malaysia and Indonesia – a region recognized by scientists as having a high degree of biological diversity.

The deepest part of the Celebes Sea is 16,500 feet. The team was able to explore to a depth of about 9,100 feet using a remotely operated camera.

“This is probably the center where many of the species evolved and spread to other parts of the ocean, so it’s going back to the source in many ways,” Madin told a group of journalists, government officials, students and U.S. Ambassador Kristie Kenney and her staff.

The project involved the Woods Hole Oceanographic Institution and National Geographic Magazine in cooperation with the Philippine government, which also provided the exploration ship.

The expedition was made up of more than two dozen scientists and a group from National Geographic, including Emory Kristof, the underwater photographer who was part of the team that found the wreckage of the Titanic in 1985.

The group returned to Manila yesterday after spending about two weeks in the Celebes Sea off Tawi-Tawi, the Philippines southernmost provincial archipelago nearly 700 miles south of Manila.

Madin said the specimens they collected included several possibly newly discovered species. One was a sea cucumber that is nearly transparent which could swim by bending its elongated body. Another was a black jellyfish found near the sea floor.

The most striking creature found was a spiny orange-colored worm that had 10 tentacles like a squid, Madin said. “We don’t know what it is … it might be something new,” he said.

Madin said it would take “a few more weeks” of research to determine whether the species are newly discovered. He expects to release a report by early next month.

Madin said the Celebes Sea, being surrounded by islands and shallow reefs, is partially isolated now and may have been more isolated millions of years ago, leading scientists to believe “there may be groups of organisms that have been contained and kept within” the basin since then.

“That makes it an interesting place to go and look to see what we might find,” Madin said.