Winghead Shark

Threat Level: low

WINGHEAD SHARK

Scientific name............Eusphyra Blochii

Family name............Sphyrnidae

GENERAL DESCRIPTION

The winghead shark is one of the smaller hammerhead sharks. They are easily identified by its emmense wing-shaped head with narrow blades, the ultimate example of the cephalofoil, measuring about half the shark's total body length. The eyes are set far apart on the extremely broad head, this may have the effect of improving the shark's stereoscopic vision. The nares are located near the middle of the head, but the nasal grooves extend along almost its full width. These wide nasal grooves can sample a very large section of the water, which may enhance the shark's ability to detect and locate odor sources. The electroreceptive ampullae of Lorenzini and mechanoreceptive lateral line on the wings have an extended distribution across the head. First dorsal fin over pectoral fin bases, further forward than other hammerheads. Upper precaudal pit longitudinal, not crescent-shaped.

SIZE

The winghead shark can grow to a maximum size of 5 to 6 feet, but commonly reaching 3 1/2 feet. Born at 13 to 18 inches ( 32-45cm ).

FEEDING HABITS

They feed on crabs shrimp, cephalopods, and small fishes, buried in the sediment.

BEHAVIOUR

Apparently pregnant females reportedly fight each other.

HABITAT

This poorly studied species is widespread along the coast of southern Asia in the Indian Ocean, and around islands of the western Pacific. It is also common in shallow tropical waters on continental and island shelves.

REPRODUCTION

Winghead sharks are live bearing (viviparous) with yolk sac placenta. They mate in spring and give birth to 6 to 20 pups, about 13 to 18" (32-45cm ) long, after 8-11month pregnancy.

SHARK ATTACKS

Not aggressive, not known to bite people, unlike the larger species.

POPULATION REPORT

They are exploited commercially in Southeast Asia, but because the winghead population has a high natural mercury content, it is not generally marketed elsewhere. Although hammerhead fins are valuable and they can die very quickly when hooked or entangled, thus live release of bycatch is unusual.