Author: Springer, 1964
Field Marks:
See key to species and diagnostic features.
Diagnostic Features:
Prenarial snout 3.7 to 4.7% of total length; upper labial furrows long, 0.3 to 1.3% of total length; total count of enlarged hyomandibular pores on both sides of head just behind mouth angle usually less than 16 (3 to 8 per side); tooth edges not regularly serrate; anterolateral teeth of adult males with slenderer, higher, more flexed cusps than females or immature males; total tooth rows usually 23 to 25/21 to 24. First dorsal origin over of just behind pectoral free rear tips; second dorsal origin ranges from above last third of anal base to just in front of its insertion; pectoral anterior margin shorter than first dorsal length from origin to free rear tip; adpressed pectoral apex reaching below first third of first dorsal base or falling in front of it. Posterior monospondylous precaudal centra hardly enlarged; precaudal centra more numerous than caudals, precaudals 84 to 91, total counts 151 to 164. Size small, males maturing at under 38 cm total length. Colour grey or brownishgrey above, pale below, bronzy when fresh, fins with dusky edges but not conspicuously marked.
Geographical Distribution:
Indo-West Pacific: The "Gulf" between the Arabian Peninsula and Iran and Pakistan to India, Sri Lanka, Malaysia, Singapore, Thailand, Kampuchea, Sumatra, Java, Madura Straits, ?China, ?Japan, Palau Islands (Angaur Island).
Habitat and Biology:
A common but little-known littoral, inshore and offshore tropical shark of the continental and insular shelves. Viviparous, with a yolk-sac placenta; number of young 3 to 5 per litter. In Bombay waters, most are born in winter (January to February).
Size:
Maximum 70 cm; males maturing females maturing between 32 and 41 cm and reaching 70 cm; size at birth between 21 and 26 cm.
Interest to Fisheries:
A common fisheries species off India, Pakistan, Sri Lanka and Thailand; taken with gillnets and line gear and utilized fresh and probably dried salted for human consumption.
Remarks:
This species is close to R. taylori, but is apparently geographically separated from it as presently known. The author follows Springer (1964) in recognizing this species as separate from R. taylori.
Type material:
Holotype: U.S. National Museum of Natural History, USNM 196799, 489 mm adult male, formerly in George Vanderbilt Foundation collection, GVF 2467. Type Locality: Gulf of Thailand, depth from 0 to 10 m.