Discovery of a Solumbellula Sea Pen - First Sighting in the Pacific!


At 2994 meters on a never-before-surveyed seamount north of Johnston Atoll, the team made a thrilling discovery — the chance to examine an animal spotted for the very first time in the Pacific Ocean! The sea pen, a colonial cnidarian, had a single large feeding polyp with pinnate (barbed) tentacles stretching over 40 cm from its 2-meter-long stalk.

Solumbellula monocephalus is the only described species in the genus and until this sighting was only known to live in the North and South Atlantic and Indian Oceans. Before this discovery of the colony, the animal had never been seen in the Pacific Ocean. 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.

Enjoy some beautiful close-ups of this coral relative that astounded our team with a detailed view of its stinging feeding tentacles that capture marine snow and food particles drifting by its home on an underwater mountain sedimented saddle. Two individuals were spotted on this dive, confirming a population within the protection of the Johnston Unit of Pacific Remote Islands Marine National Monument. 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!

Learn more about this expedition funded by NOAA Ocean Exploration via the Ocean Exploration Cooperative Institute.