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Elasmobranchii (sharks and rays) > Rajiformes (Skates and rays) > Rajidae (Skates)
Etymology: Amblyraja: Greek, amblys = darkness + Latin, raja, -ae = ray (Raja sp.) (Ref. 45335).

Environment / Climate / Range Ecology

Marine; brackish; demersal; oceanodromous (Ref. 51243); depth range 20 - 1000 m (Ref. 4426), usually 50 - 100 m (Ref. 4426). Temperate; -1°C - 14°C (Ref. 49751), preferred ?; 72°N - 33°N, 78°W - 41°E (Ref. 55275)

Distribution Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri

Eastern Atlantic: Svalbard, Greenland and Iceland to the English Channel, including the North Sea (except southern part) and the western part of the Baltic; also off Cape Town, South Africa (Ref. 5578). Western Atlantic: Greenland and Hudson Bay, Canada to South Carolina, USA (Ref. 7251).

Length at first maturity / Size / Weight / Age

Maturity: L_m 87.5 range ? - ? cm
Max length : 105 cm TL male/unsexed; (Ref. 53748); max. published weight: 11.4 kg (Ref. 53748); max. reported age: 28 years (Ref. 88929)

Short description Morphology | Morphometrics

Dorsal spines (total): 0; Anal spines: 0; Anal soft rays: 0. 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).

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). 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).

Life cycle and mating behavior Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae

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).

Main reference Upload your references | References | Coordinator : McEachran, John | Collaborators

McEachran, J.D. and K.A. Dunn, 1998. Phylogenetic analysis of skates, a morphologically conservative clade of elasmobranchs (Chondrichthyes: Rajidae). Copeia 1998(2):271-290. (Ref. 27314)

IUCN Red List Status (Ref. 115185)

Vulnerable (VU) (A2b)

CITES (Ref. 94142)

Not Evaluated

Threat to humans

Harmless

Human uses

Fisheries: minor commercial; gamefish: yes

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Estimates of some properties based on models

Phylogenetic diversity index (Ref. 82805): PD₅₀ = 0.5010 [Uniqueness, from 0.5 = low to 2.0 = high].

Bayesian length-weight: a=0.00363 (0.00297 - 0.00444), b=3.21 (3.15 - 3.27), in cm Total Length, based on LWR estimates for this species (Ref. 93245).

Trophic Level (Ref. 69278): 4.2 ±0.3 se; Based on diet studies.

Resilience (Ref. 69278): Low, minimum population doubling time 4.5 - 14 years (K=0.17; tm=4; Fec=13-20).

Prior r = 0.12, 2 SD range = 0.02 - 0.83, log(r) = -2.12, SD log(r) = 0.95, Based on: 4 K, 5 tgen, 2 tmax, 4 Fec records

Vulnerability (Ref. 59153): High vulnerability (59 of 100) .

Price category (Ref. 80766): Medium.

Amblyraja radiata (Donovan, 1808)