Squalus blainvillei

Author: (Risso, 1826)

Field Marks:
Two dorsal fins with ungrooved, very large spines, first dorsal fin height over 3/4 of its length from origin to base. First dorsal spine origin over pectoral inner margins, long prenarial snout with distance from tip to inner nostril greater than distance from nostril to upper labial furrow, tricuspidate lateral denticles, no white spots, oblique-cusped cutting teeth in both jaws, no subterminal notch on caudal fin, no anal fin, and upper precaudal pit and lateral keels on caudal peduncle.

Diagnostic Features:
Body fairly stout. Snout parabolic-rounded, broad, and moderately long, diagonal distance from snout tip to excurrent aperture of nostril greater than that from excurrent aperture to upper labial furrow, preoral snout about 1.0 to 1.3 times mouth-width, preorbital snout less than twice eye length; eyes nearer the snout tip that the first gill slits; nostrils closer to snout tip than mouth; anterior nasal flap with posterior secondary lobe rather large, though somewhat narrower at base than distance from its base to inner corner of nostril. First dorsal spine long, nearly or quite as long as fin base and with tip falling a short distance below apex of fin; second spine very long, slightly higher than fin, and usually more than 6% of total length; first dorsal fin more anterinriv situated. with fin origin about over Dectoral insertions and spine origin over pectoral inner margins and well in front of their rear tips; first dorsal very high, height over 3/4 its length from origin to rear tip; second dorsal markedly smaller than first, but with height more than 6% of total length; pectoral fins broad and semifalcate, posterior margins slightly concave, rear tips narrowly rounded; pelvic midbases about equidistant between first and second dorsal bases; caudal fin narrow-lobed and long, with long ventral lobe and strongly notched postventral margin. Precaudal pits strong. Lateral trunk denticles tricuspidate and with weakly scalloped posterior borders in adults. Colour: no white spots present on sides of body, dorsal fins with white edges, caudal without dark markings. Size moderate, up to about 1 m.

Geographical Distribution:
Eastern Atlantic: Bay of Biscay to Mediterranean, Morocco, Canaries, Senegal to Namibia (may include other species in addition to S. blainvillei). Western Pacific: Southern Japan and Taiwan Island. Nominal records of S. blainvillei or S. fernandinus from the western Atlantic gorthern Carolina to northern Gulf of Mexico (USA); Argentina), Indian Ocean (South Africa, Mozambique, Madagascar, Tanzania and India), western Pacific (Australia, New Zealand, New Caledonia), central Pacific (Hawaiian Islands), and eastern Pacific (northern Chile), as well as some records from the western North Pacific and eastern Atlantic, are based at least in part on S. mitsukurii and possibly other species. Whether S. blainvillei itself is as wide-ranging as reported for bainvillei-group dogfishes (including S. mitsukurii) remains to be determined.

Habitat and Biology:
A common temperate to tropical dogfish of the continental shelves and upper slopes, at or near the bottom at depths of 16 to at least 440 m and probably deeper; often found in large schools. Off West Africa caught on muddy bottom in water of 11 to 18°C and salinities of 36 ppt (16 to 255 m depth). Ovoviviparous, number of young 3 to 4 per litter. Eats a variety of bony fishes, including denticids, mackeral, and percichthyids, as well as crabs, lobsters, and octopi.

Size:
Maximum total length at least 95 cm; males about 50 cm at maturity, females about 60 cm at maturity; young born at about 23 cm.

Interest to Fisheries:
Common in the temperate to tropical eastern Atlantic and Mediterranean and fished there with bottom trawls, gillnets and line gear. Utilized fresh, dried salted and smoked for human consumption.

Remarks:
Limits to this species are adopted from Chen, Taniuchi and Nose (1979), and species formerly included as possible synonyms of S. blainvillei are listed elsewhere under S. mitsukurii and S. japonicus.

Type material:
Holotype: Unknown. Type Locality: Off Nice, France, Mediterranean Sea.

%LABEL% (%SOURCE%)