Remote seamounts in the Southeast Pacific could be home to 20 new species

The discovery of the seamount was a surprise, says oceanographer Jyotika Virmani, the institute’s executive director. Satellite images of the area showed only a low-resolution elevation on the sea floor. The huge seamount is thousands of meters high and its peak is 994 meters below the sea surface.

Using a submersible robot, the expedition researchers filmed and explored the new seamount and nine others, discovering a teeming ecosystem, including a garden of sponges and ancient corals about twice the width of a basketball court. The garden is not as dense as shallow-water reefs, says Virmani, which are “crammed with corals,” but still impressive for such a deep-water reef (SN: 26.10.23).

The robot encountered the ghostly white Casper octopus, named for its uncanny resemblance to the cartoon ghost Casper the Friendly Ghost. The species has yet to be officially described by scientists and was previously only known from the North Pacific.

The team also collected the first images of a living Promachoteuthis Squid. “It was pulled ashore in nets,” says Virmani. “But they were never live specimens.”

Twenty of the species discovered may be new to science and have only been found at the tops of their native seas. They add to the 150 possible new species discovered during two previous expeditions. The animals include sea anemones, sea urchins, shrimp and a spiny lobster. The team also found a fossil that could be from a new species of ancient whale, Virmani says, but this has yet to be confirmed.

“(The results) show that this part of the world is currently very little explored, but it is home to a lot of interesting wildlife.”