Speckled Skate (Raja polystigma) is moderately common, endemic species throughout the Mediterranean Sea (Serena 2005), 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), along northern African coasts (Stehmann and Brkel 1984), and eastern Algerian coasts (Bertozzi et al. 2003). The species also exists in the southern Ligurian Sea (Vannucci et al. 2006) and around Asinara Island, northwest Sardinia (Catalano et al. 2007). It is rare in the Ionian Seas (Notarbartolo di Sciara and Bianchi 1998, Mytilineou et al. 2005). In the Adriatic Sea, it is rarely captured.
Habitat and Ecology
From 100 to 400 meters.
Life History and Behavior
Molecular Biology and Genetics
Statistics of barcoding coverage: Raja polystigma
Public Records: 0
Specimens with Barcodes: 21
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
Speckled Skate (Raja polystigma) is endemic to the Mediterranean Sea. This relatively small skate (up to 60 cm total length) mainly inhabits soft bottoms on the continental shelf at depths of 100-400 m. It shows a wide geographic range in the Mediterranean Sea (mostly western and western central areas) where it is moderately common. It is part of the bycatch in fisheries using bottom trawl nets, but is also fished with gillnets, longlines and handlines in artisanal fisheries. Although little is known of the effect of fisheries on population size, its entire range overlaps intensively trawled regions. Given its small-body size, it is likely to be able to withstand moderate levels of fishing pressure. Speckled Skate is therefore assessed as Least Concern, although the status of this endemic species should be monitored.
- 2009Near Threatened (NT)
The species is found predominantly on the shelf and has been caught in the MEDITS program at depths up to 500 m (Baino et al. 2001). It is the third most abundant skate species captured in trawl surveys performed in the south Ligurian and north Tyrrhenian Sea from 1985-2004 after Thornback Skate (R. clavata) and Brown Skate (R. miraletus). In this area it occupies a very wide depth range (20-633 m) but is more concentrated between 300 and 400 m. Important catches of juveniles were recorded occasionally. Most of the collected specimens measured between 12 and 49 cm in length (Serena et al. 2005).
A study of commercial bottom trawl catch from 1995 to 2006 in the Aegean Sea caught a total of 203 specimens, with a mean catch per unit effort (CPUE) of 2.07 kilograms per hour, or 6.33 individuals per hour (Damalas and Vassilopoulou 2011). Of this catch, the majority was discarded (77.72% in weight; 93.60% in number) and the remaining fraction marketed (22.28% in weight; 6.40% in number). The same authors reported that fishery-dependent mean nominal CPUE of Speckled Skate in the central Aegean Sea has increased by 98.69% from a mean value of 0.01 individuals per hour (< 0.01 kg/h) between 1995 and 2000 to 0.71 individuals per hour (0.23 kg/h) between 2003 and 2006.
Due to the high degree of morphological similarity with Spotted Skate (Raja montagui), in the past many Speckled Skate captured in the scientific surveys have been incorrectly identified as Spotted Skate (Cannas et al. 2008).
The species is caught as bycatch in demersal trawl fisheries but is also fished with gillnets, longlines and handlines in artisanal fisheries (Bauchot 1987). There is a high level of exploitation over the continental shelf and upper slope, up to a depth of 800 m in the Mediterranean Sea (Massuti and Moranta 2003). Benthic trawl effort has increased both numerically and in technological terms in the shelf and slope area of the Mediterranean Sea over the past 50 years, even though a small decline occurred in recent years. For example, the Gulf of Lions area resources were initially exploited by small-scale benthic trawl fisheries comprising 27 small low powered boats (total nominal horse power of 2,700 hp), more recently effort has increased to a total nominal horse power of 19,940 hp (1974-1987) (Aldebert 1997).It is known to be retained and marketed along the African coasts of the Mediterranean Sea, where both trawl and artisanal fisheries operate (Bauchot 1987). This species is rarely landed separately from other rays in Italian Seas and it is not possible to monitor catches. An increase in CPUE and decrease in discards is reported in the central Aegean Sea (Damalas and Vassilopoulou 2011).