During an expedition at 2994 meters on a seamount north of Johnston Atoll, a team made a thrilling discovery by examining an animal spotted for the first time in the Pacific Ocean – a sea pen, a colonial cnidarian. The sea pen had a single large feeding polyp with pinnate tentacles that stretched over 40 cm from its 2-meter-long stalk.
Solumbellula monocephalus is the only described species in the genus and was previously only known to inhabit the North and South Atlantic and Indian Oceans. The animal had never been seen in the Pacific Ocean until the discovery of the colony. Experts will review the footage and this sample to determine if this is the first Pacific S.monocephalus or potentially a new species in this ocean basin.
The team was astounded by the close-up view of the sea pen’s 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 discovery expands the range of Solumbellula in the Pacific Ocean, highlighting the importance of ocean exploration efforts in understanding the diversity of our planet.