Centroscymnus owstoni

Author: Garman, 1906

Field Marks:
Dark brown or black coloration, no anal fin, dorsal fins with extreme tips of fin spines protruding from the fins, moderately long snout, lanceolate upper teeth and bladelike lower teeth with short, oblique cusps, fairly stocky body that does not taper abruptly from pectoral region, large lateral trunk denticles with mostly smooth, circular, cuspidate and acuspi date crowns in adults and subadults.

Diagnostic Features:
Body stocky, not strongly tapering back from pectoral region. Snout moderately long, preoral length about as long as distance from mouth to first gill slits and about equal to mouth width; lips moderately thick and fleshy; upper labial furrows very short, their lengths much less than distance between their front ends; lower teeth with short, oblique cusps and fairly high, narrow roots. Second dorsal fin considerably higher than first, fin spines small arld with tips protruding from fins; first dorsal fin exteriding forward as a short and inconspicuous ridge, origin behind pectoral bases; second dorsal base much longer than space between it and upper caudal origin, free rear tip just in front of upper caudal origin; pectoral fins moderately large, apices falling well in front of first dorsal spine when laid back; free rear tips of pelvic fins below or slightly in front of second dorsal insertion. Lateral trunk denticles large, with mostly smooth, oval, partly ridged and cuspidate crowns. Colour blackish or dark brown.

Geographical Distribution:
Western North Atlantic: Northern Gulf of Mexico. Western Pacific: Japan (southeastern Honshu), New Zealand, Australia (New South Wales).

Habitat and Biology:
A little-known deepwater dogfish of the upper continental slopes at depths of 500 to 1097 m, on or near bottom.

Size:
Maximum reported 78 cm (adult male), presumably reaching about 1 m.

Interest to Fisheries:
Nothing reported.

Remarks:
Specimens of a Centroscymnus of the owstoni-cryptacanthus type from the western North Atlantic have been tentatively assigned this name rather than C. cryptacanthus (S. Springer, pers. comm.). Examination of considerable material of eastern Atlantic Centroscymnus cryptacanthus, including the holotype, suggests that the covered fin spine that primarily separates C. cryptacanthus from this species may be variably covered or uncovered. A record of C. owstoni from the Aldabra Island group, (India) (Forster et al., 1970) was based on C. crepidater (Drs J. Bass and P.C. Heemstra, pers.comm.).

Type material:
Holotype: Museum of Comparative Zoology, Harvard, MCZ-1037, 790 mm. Type Locality: Japan.

%LABEL% (%SOURCE%)