Mol·luscs bentònics de les illes Medes (Girona). I. Sistemàtica

Resum

A list is given of the littoral benthic Mollusca collected in the hard bottoms of the Medes Islands, between 0 and 50 m deep, from samples obtained by scuba diving. These came from a two-year survey of these islands, and were sampled along 18 submarine transections on open hard bottoms and from submarine caves: they were sampled through the peeling-off of the substrate enclosed by a 400 or 1,600 cm² quadrat.
Those species not found by the authors but previously signaled by others have been added to the list; the result is a total of 255 species, subspecies and varieties of molluscs, distributed as follows: 8 Polyplacophora, 2 Scaphopoda, 168 Gastropoda (129 Prosobranchia, 38 Opisthobranchia, 1 Pulmonata), 75 Bivalvia and 2 Cephalopoda. Nearly half of these species were not previously known from the Medes Islands zone, and eight of them are new records for the Catalan littoral. This is the first paper on a series dealing with the distribution and ecology of the Mollusca of Medes Islands.