Carcharhinus longimanus
FAMILY
Carcharhinidae
TAXONOMY
Squalus longimanus Poey, 1861, Cuba.
OTHER COMMON NAMES
French: Requin océanique; Spanish: Tiburón oceánico.
PHYSICAL CHARACTERISTICS
Short and blunt snout. First dorsal fin is characteristically large, with a unique, broadly rounded apex; pectoral fins are long and also unique, with broadly rounded apex. Small second dorsal fin and large caudal fin. Broad upper teeth that are triangular with lateral serrations; lower teeth have straight, slender cusp. Gray dorsal and lateral color, with uniquely white extremities of pectoral and first dorsal fins, sometimes with darker blotches. Second dorsal, pelvic, anal, and caudal fins have dark tips; caudal extremities sometimes also white. Reaches 13 ft (4 m) in length.
DISTRIBUTION
Worldwide in tropical and temperate inshore and oceanic waters.
HABITAT
Typically occurs close to the surface, in offshore oceanic waters but may venture close to shore occasionally in waters as shallow as 121 ft (37 m). More abundant in the tropics.
BEHAVIOR
May segregate by sex and size, but little is known of its population structure. Slow moving but capable of quick bursts of energy. Oceanic whitetips appear to cruise with their pectoral fins widely spread out. Inquisitive, the oceanic whitetip will investigate potential prey items by circling them repeatedly.
FEEDING ECOLOGY AND DIET
Feeds on oceanic bony fishes of numerous families as well as on sharks and pelagic stingrays and invertebrates, such as oceanic cephalopods. Has been noted to feed voraciously on schools of fish. Also may feed on marine mammal carrion, seabirds, and turtles.
REPRODUCTIVE BIOLOGY
Viviparous, with a yolk sac placenta and litters ranging from one to 15 young. Gestation periods of about one year have been reported, but little is known about the reproductive biology. Reproductive seasons may not strictly exist, at least in the central Pacific, where gravid females have been found year-round. Lengths at sexual maturity are between 71 and 78.7 in (180–200 cm) for females and 69 and 78 in (175 to 198 cm) for males; lengths at birth vary from 23.6 to 25.6 in (60–65 cm).
CONSERVATION STATUS
Listed as Lower Risk/Near Threatened by the IUCN, because it is captured frequently as by-catch in pelagic tuna fisheries and owing to its presumably low reproductive capacity.
SIGNIFICANCE TO HUMANS
A few verified attacks on people have occurred, and the oceanic whitetip has been regarded as somewhat aggressive when approaching divers or boats. Regularly captured by pelagic longlines. The flesh is consumed fresh, dried/salted, and smoked, and the fins are coveted by the shark fin soup industry. Can be seen in the waters off Hawaii, the Red Sea, and Australia.
