ABSTRACT

A photographic and free-fall grab-sampling survey of an area rich in manganese nodules in the Clipperton-Clarion Fracture Zone of the equatorial eastern north Pacific Ocean, in depths of 4,500–5,200 meters, has revealed the presence of a conspicuous epibenthic invertebrate megafauna of more than 70 species. Approximately 38 are echinoderms: 6 asteroids, 2 ophiuroids, 3 crinoids, 2 echinoids and 25 holothurians. Most of these echinoderms are illustrated by means of seafloor photographs. For each species, where appropriate, comments are given on systematic status, geographic and bathymetric distribution, and living habits. Approximately 33% of the echinoderms of this poorly explored area are apparently restricted to the eastern Pacific in the broad sense; 30% are Atlantic and Indo-Pacific in distribution; 13% are cosmopolitan; 13% are Indo-Pacific; approximately 11% are known so far only from the Pacific Ocean. At least six species are new. The fauna includes at least one and perhaps two species of large, hitherto undescribed, swimming holothurians, which appear to spend a considerable time on the seafloor, presumably feeding.