Author: (Valenciennes, 1839)
Field Marks:
A small to fairly large, spindleshaped grey shark with moderately long rounded snout, fairly large eyes, oblique-cusped serrated teeth in both jaws, upper teeth with strong cusplets, usually 12/12 rows of anterolateral teeth, an interdorsal ridge, small pectoral fins, a moderate-sized first dorsal with a short rear tip and a small, low second dorsal with a long rear tip, and conspicuous large black tips on the ventral caudal lobe, second dorsal and pectoral fins.
Diagnostic Features:
A small to moderately large, fairly stocky and spindle-shaped species (up to about 1.6 m). Snout moderately long and pointed; internarial width 1.3 to 1.5 times in preoral length; eyes circular and moderately large, their length 1.7 to 2.4% of total length; anterior nasal flaps narrow, elongated and nipple-shaped; upper labial furrows short and inconspicuous; hyomandibular line of pores just behind mouth corners not conspicuously enlarged; gill slits fairly short, the third 2.1 to 3.3% of total length and slightly less than a third of first dorsal base; usually 12/12 rows of anteroposterior teeth in each jaw half but varying from 11 to 13/11 to 12; upper teeth with narrow, strongly serrated, oblique moderately high cusps, and crown feet with coarse proximal serrations and strong distal cusplets; lower teeth with oblique narrow serrated cusps and transverse roots, but no cusplets. A low interdorsal ridge present. First dorsal fin large and falcate, with a pointed or narrowly rounded apex and posterior margin curving ventrally from fin apex; origin of first dorsal fin varying from slightly behind to slightly in front of the pectoral free rear tips; inner margin of first dorsal moderately long, slightly less than half the dorsal base; second dorsal fin small and low, its height 1.5 to 2.2% of total length, its inner margin long and 2 to 2.6 times height; origin of second dorsal 1/3 of anal base behind anal origin; pectoral fins fairly small, falcate, with narrowly rounded or pointed apices, length of anterior margins about 16 to 18% of total length; 153 to 175 total vertebral centra, 66 to 79 precaudal centra. Body medium grey above white below; a conspicuous and large black tip on the pectorals, second dorsal, and ventral caudal lobe, but first dorsal only with black edge at most; a conspicuous white band on flank.
Geographical Distribution:
Indo-West Pacific: Mozambique and South Africa, Madagascar, Mauritius, Scychelles, Red Sea, Aden, southern Yemen, Pakistan, India, Sri Lanka Singapore, Java, ? Sumatra, ? Malaysia, Thailand, Viet Nam, China (including Taiwan Island), The Philippines, Australia (New South Wales, Queensland, western and northern Australia), Vanikoro Island (Santa Cruz Islands), Solomon Islands.
Habitat and Biology:
A common coastal, shallow-water tropical shark of the continental and insular shelves, primarily around coral reefs at depths from the intertidal down to 73 m.
Differences in vertebral counts and litter sizes between spot-tail sharks in the Red Sea and southwestern Indian Ocean may indicate relatively isolated populations there, but this needs confirmation.
Viviparous, with a yolk-sac placenta; number of young 3 to 6 per litter, commonly 6. Off Bombay, the birth season is in spring (March to May); and possibly in summer off Madagascar. Young spot-tail sharks occur in quiet, shallow water, apart from the adults.
Eats bony fishes, including bonito and sea bass, and octopi.
Size:
Maximum about 160 cm, recorded at 198 and 230 cm but possibly incorrectly; males maturing at 106 cm or below and reaching at least 128 cm, females maturing between 110 and 118 cm and reaching at least 150 cm; size at birth 45 to 60 cm.
Interest to Fisheries:
A common, wide-ranging inshore shark that apparently is regularly caught by local artisanal and smallscale commercial fisheries where it occurs, including off Pakistan, Sri Lanka, India and Thailand; taken with line gear and gillnets and utilized for human consumption; probably also used for fins and liver oil.
Remarks:
Garrick (1982) noted that the earliest species name for this shark was Squalus spallanzani Peron and LeSueur in LeSueur, 1822. The original description of S. spallanzani is Sizetchy and inadequate to establish its identity, but an unpublished and accurate drawing by LeSueur clearly does so. However, Garrick chose to retain the far better known name C. sorrah for the present species, as there is no type material for S. spallanzani, the usage of its name has been generally incorrect, and because of the inadequacy of its original description.
Type material:
Lectotype: Rijksmuseum van Natuurlijke Historie, Leiden, RHN 4294, 570 m female, Java, designated by Garrick (1982). Type Locality: "Indien, Java, Madagaskar".