Very Spiny Urchin
This urchin with very long spines was seen while exploring the crater on the southeast side of Eifuku Seamount at a depth of ~500 meters. Video courtesy of the NOAA Office of Ocean Exploration and Research, 2016 Deepwater Exploration of the Marianas. Download (mp4, 74.7 MB)
Dive 8 was conducted on the crater on the southeast side of Eifuku Seamount. The observed fauna was unexpectedly diverse – Coronaster seastars, long-spined urchins, sponges, and a variety of octocorals, including bamboo coral which appeared to be different from any described genera, were documented throughout the dive. As the remotely operated vehicle Deep Discoverer rose up a central lava dome consisting of jagged boulders with striated surfaces, much of the ridge showed diffuse low-level hydrothermal activity with temperatures reaching about 16°C. Two highlights of the dive were documenting several Randall's snappers, a commercially important species, as deep as 476 meters, constituting a new depth range extension, and an unusual mollusk that had yellow dots—a feature that has not been seen before in this genus.