Research Technical Report

Stalked Crinoids Collected off California with Descriptions of Three New Genera and Two New Species of Hyocrinidae (Echinodermata)

Pacific Science 71(3):329-365; https://doi.org/10.2984/71.3.7

ABSTRACT

Five species of stalked crinoids collected at depths from 1,693 to 4,135 m off the California coast, chiefly on seamounts, are described. Four were photographed in situ and collected during Monterey Bay Aquarium and Research Institute cruises using ROV Tiburon. Four specimens with intact crowns are attributed to Bathycrinus equatorialis A. H. Clark, 1908a, previously known from a single stalk with basal ring collected in the central eastern Pacific. Parahyocrinus claguei Roux, n. gen., n. sp., here described from a growth series of six specimens, is closely related to Hyocrinus biscoitoi Roux, 2004 (herein transferred to Parahyocrinus Roux, n. gen.), from the East Pacific Rise, but differs in features of the tegmen, pinnules, and stalk articulations. The single, finely ornamented specimen of Tiburonicrinus ornatus Roux, n. gen., n. sp., displays an original arrangement of characters suggesting affinities with Thalassocrinus alvinae from the Gorda Ridge. Gephyrocrinus messingi Roux & Lambert, 2011, known from off British Columbia and California, is transferred as type species to Lamberticrinus Roux, n. gen., after a reexamination of its pinnule architecture. Specimens of the fifth species, Bathycrinus complanatus A. H. Clark, 1908b, were trawled off California by R/V New Horizon.