October 6, 2021: Crinoid
Image courtesy of NOAA Ocean Exploration, Exploring Deep-sea Habitats off Puerto Rico and the U.S. Virgin Islands. Download larger version (jpg, 836 KB).
This crinoid (Stylmetra spinifera) was seen swimming through the water column during an Océano Profundo 2018: Exploring Deep-sea Habitats off Puerto Rico and the U.S. Virgin Islands expedition dive on a small ridge feature located west of Desecheo Island.
On this dive, we came across a dense field of feather stars, some being grazed upon by cidaroid urchins, one of their dominant predators. If necessary, some crinoids are capable of swimming short distances to escape predators or find better locations to feed. They do this by undulating their arms in a mesmerizing manner, gaining some distance above the seafloor, and gliding downward to a soft landing. Check out this video of crinoids seen during the dive.