The eight or nine species of hammerhead sharks (family Sphyrnidae) are easily recognized as a group by the mallet-shaped lateral expansions of the head. Hammerheads are closely related to the requiem sharks (family Carcharhinidae). All but one hammerhead species are placed in the genus Sphyrna; the Winghead Shark (Eusphyra blochii) is usually placed by itself in a distinct genus, Eusphyra.
The rather small and almost T-shaped Winghead Shark has narrow, unusually long wing-like head extensions that make the head nearly half as wide as the body is long. Total body length (TL) is ~100 to 150 cm, with males apparently maturing at ~108 cm TL and females maturing by ~120 cm (males are reportedly immature at 79 cm and mature at 132 cm; pregnant females are reported from 104 to 144 cm). Young are ~32 to 50 cm TL at birth.
These poorly known sharks of the tropical Indo-west Pacific are benthopelagic (i.e., occurring near the bottom or in mid-waters) and coastal. They are found in shallow waters of the continental and insular shelves. Winghead Sharks are viviparous (live-bearing) with a yolk-sac placenta. Compagno (1984) reported brood size as 6 to 11 young (most commonly 6); Castro et al. (1999) reported brood size as 6 to 25 (mean=12). Compagno et al. (1984) inferred from circumstantial evidence that the gestation period is probably around eight months, but noted the need for confirmation; Castro et al. (1999) reported the gestation period as probably around 10 or 11 months, with an annual reproductive cycle. According to Compagno (1984), the diet of the Winghead Shark is not reported, but probably consists of small fishes, cephalopods, and crustaceans. This species is not known to attack people.
Winghead Sharks are found from the Persian Gulf to Pakistan, India, Sri Lanka, Bangladesh, Burma, Malaysia, Thailand, Vietnam, China, Taiwan, the Philippines, and Indonesia to northern Australia (Queensland and Northern Territory). They are common in the fisheries of India, Pakistan, Malaysia, and Thailand (Compagno 1984).
(Compagno 1984, 1998; Castro et al. 1999; Musick and McMillan 2002; Carrier et al. 2004; Nelson 2006)
- Carrier, J.C., Musick, J.A., and M.R. Heithaus. 2004. Biology of Sharks and their Relatives. CRC Press, Boca Raton, Florida.
- Castro, J.I., Brudek, R.L., and C.M. Woodley. 1999. A preliminary evaluation of the status of shark species. FAO Fisheries Technical Paper No. 380. FAO, Rome.
- Compagno, L.J.V. 1984. FAO Species Catalogue. Volume 4. Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Part 2. Carcharhiniformes. FAO Fisheries Synopsis No. 125, Vol. 4, Part. 2: 251-655.
- Compagno, L.J.V. 1998. Sphyrnidae: hammerhead and bonnethead sharks. Pp. 1361-1366 in FAO species identification guide for fishery purposes.The living marine resourcesof the Western Central Pacific. Volume 2. Cephalopods, crustaceans, holothurians and sharks (K.E. Carpenter and K.E. Niem, V.H., eds.). FAO, Rome. Online">http://www.fao.org/docrep/009/w7192e/w7192e00.htm">Online version
- Musick, J.A. and B. McMillan. 2002. The Shark Chronicles: A Scientist Tracks the Consummate Predator. Henry Holt and Company, New York.
- Nelson, J. 2006. Fishes of the World. John Wiley and Sons, Hoboken, New Jersey.
- Stevens, J.D. and J.M. Lyle. 1989. Biology of three hammerhead sharks (Eusphyra blochii, Sphyrna mokarran, and S. lewini) from northern Australia. Australian Journal of Marine and Freshwater Research 40:129-146.
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