Author: Tanaka, 1912
Diagnostic Features:
Anterior nasal flaps greatly elongated, expanded as long, prominent barbels that reach mouth; snout flattened, short, and broadly rounded, length less than 1/3 head length and much less than distance from mouth to pectoral origins; gill openings moderately broad and about equally wide; lips thin, not pleated or suctorial teeth similar in both jaws, bladelike, interlocked, with a single oblique cusp and distal blade on a low crown and root, upper teeth slightly smaller than lowers, edges smooth; tooth rows 26 or 27/22 or 26. Both dorsal fins with long, stout, ungrooved spines; first dorsal origin just behind free rear tips of pectoral fins, insertion well in front of pelvic origins and slightly closer to pectoral bases than pelvics; second dorsal origin about over free rear tips of pelvics; second dorsal fin about as large as first, base about equally long; pectoral fins with short, narrowly rounded free rear tips, not broadly lobate or acute and attenuated; caudal fin asymmetrical, not paddle-shaped, upper lobe long, lower lobe rather short but present, subterminal notch absent or very weak. No precaudal pits but lateral keels present on caudal peduncle. Dermal denticles with low, pedicellate, tricusped and triridged flat crowns. Cloaca without a luminous gland. Colour grey-brown above, whitish below, fins with conspicuous white margins.
Remarks:
This genus has been synonymized with Squalus by Garman (1913), Fowler (1941), and lately by Bass, d'Aubrey and Kistnasamy (1976) but is retained provisionally here following Bigelow and Schroeder (1957) and Garrick and Paul (1971a). The genus differs from Squalus only in having extremely long nasal barbels. Bass, d'Aubrey and Kistnasamy (1976) have argued that C. barbifer is morphologically close to Squalus asper in having a second dorsal fin about as large as first (markedly smaller in other species of Squalus), very large denticles, a relatively short and blunt head and snout, precaudal pits absent or weak (variable in S. asper, strong in other species of Squalus), and broad base on medial lobe of anterior nasal flap (not expanded as a barbel, however, in S. asper). Bass, d'Aubrey and Kistnasamy (1976) chose to merge Cirrhigaleus with Squalus and include it, with S. asper, as a fourth species group within the genus (the acanthias, megalops, and blainvillei groups being the three others), but noted that "future authors might well name a subgenus for these two species, or even consider them as properly forming a separate genus...". This alternative classification, expressed on the generic level, would entail transferral of S. asper to Cirrhigaleus. Bass (1979) reversed this, retaining the genus Cirrhigaleus for C. barbifer, but again noted its close similarity to Squalus asper.