The diversity of a sublittoral epifaunal mollusk community of Punta Patilla, Sucre State, Venezuela, was studied from September 1990 to September 1991. We identified 25 species (14 bivalves and 11 gastropods) of mollusks that inhabit gravel, soft sand and bottoms covered by Thalassia testudinum. Total diversity indices were H´ = 3.42, J´ = 0.74 and 1-D = 0.85. Monthly diversity reached its maximum in March 1991 (3.12 bits/ ind.), June 1991 (2.88 bits/ind.) and September 1991 (2.95 bits/ind.); minimum diversity was recorded in August 1991 (1.20 bits/ind.). A log series model showed a diversity index α = 4.56 for species abundance data and α = 3.11 for biomass data. The more abundant species were Chione cancellata, Antigona listeri, Chione granulata and Arca zebra among the bivalves, and Chicoreus brevifrons, Turritella variegata and Phyllonotus pomum among the gastropods (which present maximum biomass). The average total biomass (56.80 g/m2) is low when compared to reports from other tropical zones
Keywords: community structure, diversity, macrobenthos, mollusks, venezuela