Moluscos marinos de la isla de gorgona (costa del pacifico colombiano)

Abstract

319 marine mollusk species collected yet on Gorgona Island (Pacific coast of Colom¬bia, Panamic zoogeographic province) by various persons and scientific expeditions are listed. 209 species (65.5%) inhabit the whole province (Mexico to Ecuador or Peru), 21 species (6.6%) are known from the southern part (Central America to Ecuador or Peru) and 4 species (1.3%) have their presently known northern limit in Gorgona and spread south to Ecuador or Peru. 42 species (13.2%) have their presently known southern distribution limit in Gorgona, 14 other species (4.4%) reaching in Gorgona their southernmost point on the continental shelf of South America are also known from Gala'pagos. 3 species (1.0%) have been collected on the continental shelf only in Gor¬gona and partly in Costa Rica. The distribution of the remaining 25 species (7.9%) is still not sufficiently known. 119 species from Gorgona have not yet been found on the mainland coast of Colombia. 8 species are amphipacific. The zoogeographic importance of Gorgona Island is based in the fact that the island is the southernmost point on the continental shelf with extensive coraline biotopes within the Panamic-Pacific faunal province.