Diet of Risso’s dolphin (Grampus griseus) in the western Mediterranean Sea

is a moderately large and cosmopolitan dolphin species that lives in deep tropical and warm temperate oceanic waters. Data on its distribution in the Mediterranean are very scarce but sightings seem to indicate that the species prefers the slope, mostly where the slope is closest to the coastline (Notarbartolo di Sciara et al., 1993). There are few studies on the diet of Risso’s dolphin and they are frequently based on one or two individuals, except for data coming from the east coast of South Africa (Cockroft et al., 1993). In general its diet has been considered mainly teuthophagous with fish as an occasional component (Goodall and Galeazzi, 1985). The diet of Risso’s dolphin includes neritic, oceanic and bottom dwelling cephalopods. Data on its diet in the Mediterranean comes from studies on one harpooned (Pilleri and Gihr, 1969) and one or two stranded individuals, which were summarised by Clarke (1996) and which corroborate the teuthophagous character of the diet. The aim of this note is to provide more complete information about the poorly known diet of this dolphin. The gastrointestinal tracts analysed in the present work came from fifteen Risso’s dolphins stranded on the Mediterranean west coast between 40o25’N SCIENTIA MARINA 70 (3) September 2006, 407-411, Barcelona (Spain) ISSN: 0214-8358