Amblyraja radiata (Donovan 1808)

Adults are rhomboid in shape, young are rounder (Ref. 7251). Short, stiff, bluntly triangular snout; tail shorter than body (Ref. 5578). Upper surface very rough, with solid thornlets scattered all over disc and tail, underside smooth, except for some prickles on snout; a constant pattern of separate orbital thorns, a regular row of 13-17 large thorns from nape to first dorsal fin (Ref. 3167); large, close-set thorns with star-shaped bases at upper disc (Ref. 5578). Coloration highly variable; brownish grey with scattered irregular black blotches dorsally; white ventrally; with darker spots and blotches on tail and pelvic fins; black spot on tip of tail (Ref. 2708).

Distinct pairing with embrace. Oviparous, laying 10-45 egg cases each year (Ref. 44869, 41305). Eggs are oblong capsules with stiff pointed horns at the corners deposited in sandy or muddy flats (Ref. 205). Egg capsules are 3.4-8.9 cm long and 2.3-6.8 cm wide (Ref. 41250). Paired eggs are laid. Embryos feed solely on yolk (Ref. 50449). In the North Sea, fully formed individuals hatch after 4 months and pups are about 8-11 cm in length (Ref. 44869, 37969). In the Barents Sea, low water temperature may lengthen embryonic development time to 2.5-3 years (Ref. 44869).

Oceanodromous. Migrating within oceans typically between spawning and different feeding areas, as tunas do. Migrations should be cyclical and predictable and cover more than 100 km.

Dorsal spines (total): 0; Analspines: 0; Analsoft rays: 0

A boreal to arctic species, living offshore on hard and soft bottoms at temperatures of -1.4-14°C. Epi- to mesobenthic, on clay and mud bottom from littoral zone to depths of more than 1,000 meters (Ref. 119696). Seasonal shoaling of juveniles assumed from bulk catch with great concentrations of juveniles found throughout the Gulf of Maine, Massachusetts Bay, the Bay of Fundy, the Scotian Shelf, and the perimeter of Georges Bank during spring and fall seasons; both the spring and fall 1978-2002 Massachusetts inshore trawl surveys show concentrations of juvenile thorny skate around Cape Ann and into Massachusetts Bay, and in Cape Cod Bay (Ref. 49751). Based on tagging experiments, does not appear to make seasonal migrations; known to be rather sedentary (Ref. 86779).

Eurybathic, eurythermic (Ref. 4426) and benthic (Ref. 58426). Cold temperate species found in offshore waters (Ref. 88171) on all kinds of bottoms (Ref. 3167), mainly sandy and muddy (Ref. 82311). In the northeast Atlantic most common between 50-100 m depth (Ref. 88187) at temperatures of 2-5 °C (Ref. 89120). Some seasonal migrations have been reported from the western Atlantic (Ref. 52109, 89121). Migration experiments showed that 85 % of tagged individuals remained within 93 km of the release site, with longest distance travelled at 180 km (Ref. 82319). Feed mainly on fish, crustaceans (Ref. 5951) and polychaete worms (Ref. 5578), but also on hydroids, molluscs, cephalopods and echinoderms (Ref. 49751); known to be a scavenger (Ref. 89122). Diet changes with increasing body size (Ref. 82311). Different populations of starry rays mature at different ages and sizes (Ref. 88171). Oviparous (Ref. 3167). Maturity size varies from 44-90 cm TL. Young hatch at ca. 8-12 cm TL (Ref. 114953). Young may tend to follow large objects, such as their mother (Ref. 205). Rarely reaches 60 cm in the North Sea (Ref. 88187). Able to detect weak electric fields generated by potential prey organisms and may also generate its own weak electric fields (Ref. 10311). Probably taken by hake trawlers (Ref. 5578). Few are dried and salted in Iceland (Ref. 6902). It has been mentioned that North American specimens grow to a larger size than East-Atlantic specimens (Arve Lynghammar, pers.comm., 11/09).

fisheries: minor commercial; gamefish: yes; price category: medium; price reliability: very questionable: based on ex-vessel price for species in this family