Author: (Müller and Henle, 1839)
A large fairly slender grey shark with a long pointed snout, small eyes, unusually long (for a grey shark) upper labial furrows, narrow, mostly erect- and narrow-cusped serrated or partly serrated upper antero- lateral teeth without cusplets, long gill slits, lower teeth with narrow, smooth-edged cusps, usually 16/15-16 rows of anterolateral teeth, no interdorsal ridge, small pectoral fins, a small first dorsal with a short rear tip and a moderately large second dorsal with a short rear tip, and usually black tips on most fins in juveniles.
A large, slender to slightly stocky species (up to about 2.8 m). Snout long and pointed or narrowly rounded; internarial width 1.5 to 1.8 times in preoral length; eyes circular and fairly small, 1.1 to 2% of total length; anterior nasal flaps relatively low and inconspicuous; upper labial furrows usually long and conspicuous, directed obliquely anterolaterally;hyomandibular line of pores just behind mouth corners not conspicuously enlarged; gill slits long, third 3.7 to 5.5% of total length; usually 16/15 rows of anteroposterior teeth in each jaw half but varying from 15 to 18/14 to 17; upper teeth with narrow, finely serrated, erect to slightly oblique, long cusps, and crown feet with fine serrations but no cusplets (serrations often irregular in young); lower teeth with erect, usually smooth-edged narrow cusps and transverse roots. No interdorsal ridge. First dorsal fin small and semifalcate, with pointed or narrowly rounded apex and posterior margin curving ventrally from apex; origin of first dorsal fin usually over or slightly posterior to pectoral free rear tip; inner margin of first dorsal short, a third of dorsal base or slightly less; second dorsal fin moderately large, its height 1.8 to 2.6% of total length, its inner margin short and 1.4 to 1.9 times its height; origin of second dorsal over or usually slightly behind anal fin origin; pectoral fins falcate, with narrow, pointed or narrowly rounded tips; relatively small, about 14 to 16% of total length in specimens above 100 cm and slightly smaller in young; 155 to 185 total vertebral centra, 84 to 96 precaudal centra. young plainfinned but large juveniles to adults with black tips usually present on pectorals, second dorsal, anal and ventral caudal lobe, and sometimes on pelvics, first dorsal and dorsal caudal lobe. A white band on flanks, but often this is not conspicuous.
Western Atlantic: Northern Carolina to Florida, Bahamas, Cuba, northern Gulf of Mexico, British Guiana, southern Brazil. Eastern Atlantic: Mediterranean, Cape Verde Islands, Senegal, Guinea and Sierra Leone, Togo and Nigeria, Angola. Indo-West Pacific: South Africa, Madagascar, Mauritius, Scychelles, Mozambique, Red Sea, Gulf of Aden, Oman, India, Singapore, Indonesia, (Java, Sumatra), Viet Nam, Japan, New Guinea, Australia (Queensland, New South Wales, Western Australia), possibly the Philippines.
Habitat and Biology:
A common coastal-pelagic, warm-temperate and tropical shark of the continental and insular shelves, ranoing close inshore and offshore; common in shallow waters at a depth less than 30 m, but ranging down to at least 75 m depth, from the surface to the bottom. The spinner shark is a schooling, active species like C. limbatus, but more commonly leaps spinning out of the water. Off Florida and Louisiana in the Gulf of Mexico, USA these sharks are highly migratory, moving inshore in spring and summer for reproduction and feeding, but possibly moving southward and into deeper water during the autumn and winter.
Viviparous, with a yolk-sac placenta; number of young 3 to 15, with larger females carrying more young. Off South Africa young are usually born in the autumn although some may be born in winter, after a gestation period of 12 to 15 months. Off Senegal young are born in summer while in the Gulf of Mexico off Florida and Louisiana young are born in spring to early summer. In the Gulf of Mexico adult sharks remain in shallow water during the summer but retreat possibly southward or into deeper water in the autumn. The Natal coast serves as a nursery ground for one population of this shark; adultfemales occur there throughout the year while males seasonally occur during the summer. Tagging studies in South African waters suggest that young sharks prefer slightly lower temperatures than adults, and tend to move south and Capeward from Natal when temperatures Increase.
Primarily a fish-eater, the diet including ten-pounders (Elops), sardines and herring, anchovies, sea catfish, lizardfish, mullets, bluefish, tunas, bonito, croakers, jacks, mojarras, grunts, tongue-soles, stingrays, cuttlefish, squid and octopi. It frequently uses an unusual method of feeding on schools of small bony fishes that gives this shark its common name; it swims rapidly upward through the schools with open mouth, spinning along its long axis and snapping in all directions, and then shoots out of the water after its feeding run. Off Madagascar this species is associated with and probably feeds on migrating schools of scombrids and jacks. As with C. limbatus, this species will congregate to eat trash fish dumped off shrimp trawlers, and no doubt participates in feeding frenzies like its smaller relative.
In at least one instance this shark apparently attacked a bather; however, like its relative C. limbatus, it is probably not highly dangerous, but could be troublesome to divers when they are spearfishing. It has small, narrow-cusped teeth (smaller than in C. limbatus) that are clearly not adapted for feeding on large prey, and probably greatly prefers whole small fishes to mammalian prey.
Maximum reported 278 cm, males maturing at 159 to 203 cm and reaching at least 233 cm, females maturing at 170 to 200 cm and reaching 278 cm; size at birth about 60 to 75 cm.
Interest to Fisheries:
Apparently regularly caught in fisheries where found, with pelagic longlines, fixed bottom nets, and on hook-and-line; meat utilized fresh and dried salted for human consumption; also valuable for hides and fins, and for liver oil (vitamins).
This common and wide-ranging shark has often been confused with its somewhat smaller relative, C. limbatus, in the past, but in addition various growth stages of this shark in different areas has often been considered separate species. The coloration and tooth serrations of this shark change markedly with growth, and these changes have resulted in much confusion in the literature (see Garrick, 1982, for a discussion of the taxonomy and nomenclature of this species).
Bass, D'Aubrey and Kistnasamy (1973) and Garrick (1982) separated this species from C. limbatus by its smooth-edged lower teeth, longer, slenderer body, shorter smaller fins, more posterior first dorsal origin, and black-tipped anal fin (in sharks over 130 cm long, smaller with plain anal fins like C. limbatus at all sizes). Branstetter (1982) analysed the characters used to separate the two species and noted overlap in lower tooth serrations, first dorsal origin position, and eye size, but noted the species could be separated by the following characters: a lower first dorsal fin (height equal to preorbital space, versus much greater in C. limbatus; or height greater than 2.2 times in interdorsal space, versus about equal to or less than 2.2 times in interdorsal space), with a more rounded apex and vertical posterior margin (more pointed and falcate in C. limbatus) and its origin more posterior in adults (and probably large juveniles; over or behind the pectoral rear tips, versus about opposite the pectoral insertions in C. limbatus); a longer snout, with prenarial space 1.1 to 1.4 times distance from front of nostrils to mouth (0.7 to 1 in C. limbatus); higher tooth row counts with some overlap (usually 16 rows of upper anteroposterior teeth in C. brevipinna, usually 15 in C. limbatus,with the two respectively varying from 15 to 18 and 14 to 16 rows of these teeth); Meckel's cartilage without a posterior notch just below the mandibular joint (present in C. limbatus); and anal fin black-tipped (even in sharks a few months old in the Gulf of Mexico, but possibly not attained until a greater age and size in the western Indian Ocean). In sorting out piles of small sharks in the field in India, the writer found that the long diagonal upper labial furrows of this species were very useful in separating spinner sharks from other species, including C. limbatus, as was its slender body, long gill slits, long narrow snout, small fins and small teeth.
Holotype: Rijksmuseum van Natuurlijke Historie, RHN 2525, 785 mm mounted skin. Type Locality: Java.