Elasmobranchii (sharks and rays) >
Rajiformes (Skates and rays) >
Rajidae (Skates)
Etymology: Raja: Latin, raja, -ae = a sting ray (Raja sp.) (Ref. 45335). More on author: Linnaeus.
Environment / Climate / Range
Ecology
Marine; demersal; depth range 10 - 577 m (Ref. 56504). Subtropical; 70°N - 29°S, 25°W - 42°E
Length at first maturity / Size / Weight / Age
Maturity: Lm 76.7, range 48 - 87.5 cm
Max length : 105 cm TL male/unsexed; (Ref. 53748); 139.0 cm TL (female); common length : 85.0 cm TL male/unsexed; (Ref. 9987); max. published weight: 18.0 kg (Ref. 35388); max. reported age: 15 years (Ref. 41305)
Dorsal
spines
(total): 0;
Anal
spines: 0;
Anal
soft rays: 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).
Eastern Atlantic: Iceland, Norway, North Sea and the western Baltic southward to Morocco and Namibia, including the Mediterranean and the Black Sea. Although reported from southern Africa, its status in the area is uncertain (Ref. 5578).
Inhabits shelf and upper slope waters. Depth range 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). 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). 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).
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.
IUCN Red List Status (Ref. 90363)
Threat to humans
Harmless
Human uses
Fisheries: commercial; gamefish: yes
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Estimates of some properties based on empirical models
Phylogenetic diversity index (Ref.
82805): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00269 (-0.05031 - 0.05568), b=3.22788 (3.19932 - 3.25645), based on LWR estimates for this species (Ref.
93245).
Trophic Level (Ref.
69278): 3.8 ±0.6 se; Based on diet studies.
Resilience (Ref.
69278): Low, minimum population doubling time 4.5 - 14 years (K=0.09-0.14; tm=10; tmax=23; Fec=150).
Vulnerability (Ref.
59153): Very high vulnerability (76 of 100) .
