Raja polystigma is moderately common throughout the Mediterranean Sea, particularly in the western (Morocco, Spain and France) and western central areas (Tyrrhenia, Corsica, Sardinia and Sicily) (Baino et al. 2001 Ragonese et al. 2003, Florio et al. 2003, Follesa et al. 2003, Spedicato et al. 2003, Serena 2005, Mancusi et al. 2005), rare in Adriatic and Ionian Seas (Notarbartolo di Sciara and Bianchi 1998), common along northern African coasts (Stehmann and Burkel 1984) and eastern Algerian coasts (Bertozzi et al. 2003).

It is found predominantly on the shelf and has been captured in the Mediterranean International Trawl Surveys (MEDITS) down to depths of 500 m (Baino et al. 2001). The overall biomass index assessed with MEDITS surveys (0-800m deep) in the west, north and eastern Mediterranean was 1.1 kg/km² (Baino et al. 2001). It was captured in 171 out of 6,336 survey tows between 1994 and 1999 and its estimated standing stock biomass throughout the northern Mediterranean Sea is 568t. Following R. clavata and R. miraletus, R. polystigma is the third most abundant skate species captured in trawl surveys performed in the south Ligurian and north Tyrrhenian Sea from 1985?2004. In this area it occupies a very wide depth range (20?633 m) concentrating between 300 and 400m. Important catches of juveniles were recorded occasionally (Serena et al. 2005). Most of the collected specimens measured between 12 and 49 cm in length (Serena et al. 2005).

Stable