Author: Bocage and Capello, 1864
Field Marks:
Greyish or blackish-brown, no anal fin, small fin spines present on both dorsal fins though sometimes inconspicuous (C. cryptacanthus), short to moderately long snout, slender-cusped teeth without cusplets in upper jaw, bladelike, oblique and short-cusped, interlocked cutting teeth in lower jaw, caudal fin with a strong subterminal notch, and pectoral fins with broadly rounded free rear tips.
Diagnostic Features:
Anterior nasal flaps short, not expanded as barbels; snout flattened, broadly parabolic, length varying from about equal to distance from mouth to pectoral origins to considerably less than that space, and about half length of head or less; gill openings moderately wide and about equal-sized; lips thick but not pleated or suctorial; teeth very different in upper and lower jaws, uppers with very slender, acute cusps and no cusplets, not bladelike, lower teeth high compressed, bladelike, interlocked with short, oblique cusps, distal blades, and no cusplets; tooth rows 39 to 70/32 to 42. Small, grooved finspines present on both dorsal fins, these sometimes covered with skin and inconspicuous; first dorsal origin varying from over the pectoral bases to well posterior to their free rear tips, insertion well in front of pelvic origins and closer to the pectoral bases than the pelvic bases; second dorsal origin about over the middle of the pelvic bases; second dorsal about as large or slightly smaller than first, but first often with an anteriorly elongated base up to about twice as long as that of first; pectoral fins with short, broadly rounded free rear tips and inner margins, not broadly lobate or acute and attenuated; caudal fin asymmetrical, not paddle-shaped, upper lobe long, lower lobe short but well-developed, subterminal notch present and strong. No precaudal pits or lateral keels on caudal peduncle. Dermal denticles with low, pedicellate, flat, ovoid crowns, varying from triridged and tricuspid to smooth and acuspidate in adults, triridged and tricuspidate in young. Cloaca without a luminous gland. Colour blackish brown or greyish brown above and below.
Remarks:
The separation of this genus from Scymnodon is unsatisfactory with criteria in current usage, but I hesitate to merge them pending further work on the problem. I use Bigelow and Schroeder's (1957) rather than Garrick's (1959a,b) or Bass, d'Aubrey and Kistnasamy's (1976) limits for the two genera, and include only species with very long cusps on their lower teeth in Scymnodon (S. ringens, S. obscurus, and S. squamulosus). Centroscymnus as presently delimited includes C. coelolepis, C. crepidater, C. cryptacanthus, C. macracanthus, C. owstoni, and C. plunketi. An additional species, C. fuscus Gilchrist and von Bonde, 1924, was placed in synonymy of Centrophorus squamosus by Bass, d'Aubrey and Kistnasamy (1976).