Dipturus batis (Linnaeus, 1758)
Blue skate
photo by Cambraia Duarte, P.M.N. (c)ImagDOP

Family:  Rajidae (Skates)
Max. size:  285 cm TL (male/unsexed); max.weight: 113 kg; max. reported age: 51 years
Environment:  demersal; marine; depth range 100 - 1000 m
Distribution:  Northeastern Atlantic: Iceland to the British isles; it was formerly more widespread, including the Mediterranean Sea and North Africa, but the range is thought to be reduced due to fishing.
Diagnosis:  Dorsal spines (total): 0-0; Anal spines: 0-0; Anal soft rays: 0-0. This species is characterized by the following: snout broadly angular, length 5-6.3 times orbit length; disc broadly rhombic, anterior margin deeply concave; a row of 12-31 predorsal thorns in median row along tail (disc smooth in young; denticles confined to dorsal head and along anterior disc margin on both surfaces in adults; disc thorns small in young, largely absent in adults); lateral thorns on tail perpendicular to body axis; interspace between dorsal fins 1.2 ± 0.4 TL, the fins rounded, upright, near tail tip; upper surface olive-grey or brown with a variable pattern of light blotches, with yellowish ring-like markings; underside greyish; iris yellowish (Ref. 114953, 127223).
Biology:  Benthic species in shelf and slope waters, mainly within the 200 m range along the continental shelf, but down to 600 m along continental slopes and seamounts (Ref. 127222). Feeds on all kinds of bottom invertebrates and fish, including other skates (Ref. 114953). Oviparous, with long embryonic development. Males reach maturity at ca. 115 cm TL, females at 123 cm TL; birth size at ca. 21 cm TL (Ref. 114953). Biology may be unclear due to past taxonomic confusion Distinct pairing with embrace. Young may tend to follow large objects, such as their mother (Ref. 205). Mate in spring and the egg capsules are laid during the summer. Eggs are oblong capsules with stiff pointed horns at the corners deposited in sandy or muddy flats (Ref. 205). Egg capsules are 10.6-24.5 cm long and 5.0-14.5 cm wide (Ref. 41250). About 40 eggs per individual are laid annually (Ref. 41250). Flesh is marketed fresh or smoked (Ref. 35388).
IUCN Red List Status: Critically Endangered (CR); Date assessed: 02 April 2021 (A2bcd) Ref. (130435)
Threat to humans:  harmless

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