The sea pen made its appearance during a visit by a remotely operated vehicle, or ROV, to an unexplored seamount near Johnston Atoll, a remote spot to the west of Hawaii in the Pacific. It was unexpected. This is the first time this animal has been spotted in the Pacific. It’s normally found in the Atlantic and Indian Oceans. The Nautilus came across two examples during the dive.
A video shot at a depth of 9,823 feet (2,994 meters) shows the moment of discovery, along with commentary from excited researchers. “That looks wicked,” says one of them after the ROV got a close-up shot of the creature’s food-capturing tentacles. For scale, the sea pen’s stalk is 6.6 feet (2 meters) long.
Sea pens are filed under cnidarians, a broad group of aquatic animals that includes corals and jellyfish.
“Further review of the footage and this sample will help experts determine if this is the first Pacific S.monocephalus or potentially a new species in this ocean basin,” the Nautilus team said on YouTube.
The research expedition at Johnston Atoll ran from June 20 to July 13 and was focused on studying the biodiversity of the area. The nonprofit Ocean Exploration Trust operates the ship and streams many of its ROV dives.
At 2994 m on a never-before-surveyed #seamount, we made a thrilling discovery of an animal spotted for the first time in the #PacificOcean! The #seapen, a colonial #cnidarian, had a single large feeding polyp with pinnate tentacles stretching over 40 cm from its 2m-long stalk. pic.twitter.com/oFKowZMmIo— E/V Nautilus (@EVNautilus) July 15, 2022
E/V Nautilus has lifted the veil on many wonders of the deep, from a rare jellyfish to a delightful “unidentified gelatinous creature.” Said the team, “This huge range expansion of Solumbellula in the Pacific Ocean reminds us how important ocean exploration efforts are to understanding this diversity of our planet.”