Raja clavata Linnaeus, 1758
Thornback ray
Raja clavata
photo by Stergiou, K.I.

Family:  Rajidae (Skates), subfamily: Rajinae
Max. size:  105 cm TL (male/unsexed); 139 cm TL (female); max.weight: 18 kg; max. reported age: 15 years
Environment:  demersal; depth range 5 - 1020 m
Distribution:  Eastern Atlantic and Southwest Indian Ocean: Iceland to Madagascar, including the Mediterranean Sea.
Diagnosis:  Dorsal spines (total): 0-0; Anal spines: 0-0; Anal soft rays: 0-0. Sub-rhomboid in shape with pointed wing-tips; disc-width 1,25 to 1,36 times in its length, its length 1,70 to 1,83 times in total length. Short rostrum, rounded at his extremity; pectoral fins with clear angles on lateral side; triangular pelvic fins (Ref. 39246). Dorsally prickly; large females also prickly throughout their ventral surface; juveniles and large males prickly along the margins of their discs and the underside of their snout. 30-50 thorns form a median row from the nape to the first dorsal fin; additional large 'buckler' thorns with swollen bases scattered on upper surface of disc in adults (Ref. 3167). Coloration is highly variable, with the dorsal surface having all shades of brown with dark and light spots and blotches; ventral surface white (Ref. 3167, 58137).
Biology:  Inhabits shelf and upper slope waters. Reported depth ranges varies, from 10-300 m (Ref. 4426, 82319, 88187), and from 300-577 m in the eastern Ionian Sea (Ref. 56504); most common in coastal waters between 10-60 m depth (Ref. 58137). Tolerates low salinities (Ref. 88171). Found on mud, sand and gravel bottoms, rarely on rougher bottoms (Ref. 6808, 58137). Nocturnal species. Feeds on all kinds of bottom animals, preferably crustaceans (Ref. 3167) and fishes (Ref. 114953). Undertakes migrations with mean distances of 54-117 km per month; shows a clear annual migration cycle (Ref. 89017, 89018), moves from deeper offshore waters (10-30 m) in autumn and winter to shallower areas (<10 m) in spring (Ref. 82319). Young are non-migratory, inhabiting inshore nursery grounds (Ref. 89019, 89020, 89022); in the Bay of Douarnenez (France) they are found to remain in shallow waters for at least 2 years (Ref. 89023). Maturity age 7-8 years (Ref. 114953). Oviparous. Young may tend to follow large objects, such as their mother (Ref. 205). Detects weak electric fields generated by other organisms (prey detection and predator avoidance) but may also generate its own weak electric fields (Ref. 10311, 88171). Utilized fresh and frozen (Ref. 9987).
IUCN Red List Status: Near Threatened (Ref. 115185)
Threat to humans:  harmless
Country info:  Reported from 20-180 m depth. Also Ref. 3167.

Entered by: Luna, Susan M. - 18.01.91
Modified by: Capuli, Estelita Emily - 09.09.17
Checked by: Capuli, Estelita Emily - 09.09.17

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