Author Type

Faculty

Document Type

Article

Abstract

The molluscan community associated with the scleractinian coral Oculina varicosa is compared among four reef sites: inner shelf (6 m), midshelf (27 m), outer shelf (42 m), and shelf edge (80 m). Enumeration ofall the mollusks from 41 coral samples yielded 5,132 individuals and 230 species-level taxa, including 155 gastropods, 68 bivalves, I scaphopod, 5 polyplacophorans, and I cephalopod. Of these taxa, approximately 47% were free living (motile), 32% symbiotic (parasitic or commensal), 18% epilithic (fouling), and 3% endolithic (boring). The species assemblage at the 80-m reef was very distinct from that at 6 m. Approximately 75% of the individuals collected at 6 m were herbivores or detritivores; higher light levels and sedimentation from wave surge at this station may account for this dominance. Carnivores dominated at the 80-m station (62.1% ofthe individuals) but were uncommon at 6 m (4.8%). At the 80-m station, greater coral coverage permitted more coral-eating mollusks, and greater percentage of dead coral per colony enabled more epilithic species and associated symbionts to exist. The corallum of O. varicosa was denser at 80 m and the branches were generally thinner than at 6 m, possibly accounting for the fewer numbers and species ofboring mollusks at the 80-m reef. Periodic coldwater upwelling and cooler average temperatures may account for the greater numbers of eurythermic tropical, temperate, and boreal species at the 80-m reef than at the 6-m reef.

Publication Date

1987

Comments

Florida Atlantic University. Harbor Branch Oceanographic Institute contribution #541.

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