CS06 Benthos
Date: Tuesday, June 11, 2002
Location: Poster Session - VCC
 
ArellanoSM, Harbor Branch Oceanographic Institution, Ft. Pierce, USA, sarellano@hboi.edu
Young, C, M, Harbor Branch Oceanographic Institution, Ft. Pierce, USA, youngc@hboi.edu
 
SMALL-SCALE DISTRIBUTION AND DIVERSITY OF EPIBIONTS LIVING ON THE STALKS OF AN ABUNDANT HEXACTINELLID SPONGE FROM THE HAWAIIAN SLOPE
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The hexactinellid sponge Seriocolophus hawaiicus occurs between 325 and 490 m off Kona, Hawaii, where it dominates the zone of highest megafaunal density on the Hawaiian Slope. The sponges themselves provide substrate for a diverse assemblage of epibionts and their stalks stabilize the substratum, providing hard surfaces for epibionts even after the sponges themselves have died. We compared epifaunal abundance and distribution along the stalks of living and dead sponges collected with the Pisces V submersible. Stalks of S. hawaiicus hosted at least 14 species of epibionts. Species diversity was similar on stalks of living and dead sponges, although scalpellid barnacles, the most common epibionts, were significantly more abundant on dead stalks. Benthic ctenophores, Lyrocteis sp., occupied the tips of dead stalks, but were never found on living sponges. Sponges oriented into prevailing currents. On stalks of both living and dead sponges, barnacles occurred mostly on the upstream side. However, they were most abundant near the tops of dead stalks and in the middle of living stalks. These small-scale distributional differences can probably be explained by flow patterns at settlement.