Author: Blainville, 1816
Diagnostic Features:
Snout moderately long and parabolic in dorsoventral view, preoral length about equal to mouth width; eyes horizontally oval and lateral, subocular ridges obsolete; anterior nasal flaps vestigial, formed as small, low, angular points, well separated from each other and mouth; no nasoral grooves; internarial width over 2.5 times nostril width; mouth broadly arched and long; labial furrows moderately long, uppers ending well behind level of upper symphysis; teeth bladelike, compressed, and cuspidate, similar in upper and lower jaws, anteroposteriors with oblique cusps and cusplets; medial teeth well differentiated from anteroposteriors. First dorsal fin moderately large, base half length of dorsal caudal margin or less; its origin over or slightly behind pectoral free rear tips, its midbase slightly closer to pectoral bases than pelvics; second dorsal much smaller than first, less than half height of first; anal fin about as large as second dorsal; ventral caudal lobe strong in young and adults; terminal lobe of caudal fin long and about 2 times in dorsal caudal margin.
Remarks:
The scope of this genus follows the revisions of Compagno (1970, 1973b, 1979). Eugaleus omanensis Norman, 1939, Galeus japanicus Müller and Henle, 1839, Eugaleus hyugaensis Miyosi, 1939, and Galeorhinus (Hypogaleus) zanzibariensis Smith, 1957 are here included in the genera Iago (omanensis), Hemitriakis (japanicus), and Hypogaleus (heugaensis and zanzibariensis). Other than these species, several species of true Galeorhinus have been recognized for different geographic regions: G. rhinophanes (Peron, 1807) or G. australis (Macleay, 1881) from Australia and New Zealand; G. Zyopterus (Jordan and Gilbert, 1883) for the eastern North Pacific; G. chilensis (Perez Canto, 1886) for Peru and Chile; G. vitaminicus de Buen, 1950 from the eastern South Atlantic; and G. galeus from the eastern Atlantic. Comparison of accounts and specimens of these regional species of Galeorhinus indicated that they probably are not separable and should be placed in a single species (Compagno, 1979), possibly subdivided into subspecies. The eastern North Pacific Galeorhinus averages slightly more vertebrae and apparently matures at a somewhat larger size than other Geleorhinus, but is otherwise very similar to them. All the nominal species of Galeorhinus are included here under Galeorhinus galeus.