Hammerhead - Smooth

Up to 16 ft (6 m), but generally under 10 feet. 500 to 1,000 lbs (230 to 450 kg)

Family	Sphyrnidae
Description	Hammerhead, bonnethead, or scoophead sharks
Environment	Brackish & Marine
Etymology	Greek, sphyra = hammer
Genus	2
No. of Species	10
Order	Carcharhiniformes
Class	Elasmobranchii
Reproductive Guild	Bearers
Distribution	Marine, coastal; occasionally in brackish water. Distribution: global (chiefly warm waters). Head laterally expanded, with eyes and nasal openings much wider set than in other sharks. The blades presumably server to increase the sharks' sensory capabilities. No spiracle. A maximum length of 4.5 m was reported for Sphyrna tudes. They feed on a wide variety of bony fish, elasmobranchs, cephalopods, crustaceans, and other prey. Young born fully developed. Potentially dangerous.

Common Hammerhead

In Hawaii, juveniles have been caught at depths of about 110-225 ft. Occurs inshore and well offshore (Ref. 5578), over continental and insular shelves. Coastal, pelagic, and semi-oceanic, but often bottom associated at 1-139 m. Migrates northward in summer; young often in large aggregations of hundreds of individuals. Prefers to feed on small sharks, skates and stingrays, but also preys on bony fishes, shrimps, crabs, barnacles and cephalopods. Viviparous. Regarded as being dangerous to people, though only few can be tentatively attributed to this species due to its occurrence in temperate waters. Reported to cause poisoning . Caught occasionally by shark and tuna longline fisheries. Meat utilized fresh, dried-salted, and possibly smoked for human consumption; liver oil for vitamins, fins for soup, hide for leather, and carcasses for fishmeal. Used in Chinese medicine. Become sexually mature when 250 to 300 cm long.

Hammerhead sharks are consummate predators that use their oddly shaped heads to improve their ability to find prey. Their wide-set eyes give them a better visual range than most other sharks. And by spreading their highly specialized sensory organs over their wide, mallet-shaped head, they can more thoroughly scan the ocean for food. One group of sensory organs is the ampullae of Lorenzini, which allows sharks to detect, among other things, the electrical fields created by prey animals. The hammerhead's increased ampullae sensitivity allows it to find its favorite meal, stingrays, which usually bury themselves under the sand. The great hammerhead is the largest of the nine identified species of this shark. It can grow up to 20 feet (6 meters) in length and weigh up to 1,000 pounds (450 kg), although smaller sizes are more common. Found in temperate and tropical waters worldwide, far offshore and near shorelines, hammerheads are often seen in mass summer migrations seeking cooler water. They are gray-brown to olive-green on top with off-white undersides, and they have heavily serrated, triangular teeth. Their extra-tall, pointed dorsal fins are easily identifiable. Most hammerhead species are fairly small and are considered harmless to humans. However, the great hammerhead's enormous size and fierceness make it potentially dangerous, though few attacks have been recorded. The squat-headed hammerhead (Sphyrna mokarran) and the scalloped hammerhead (Sphyrna lewini) are listed as endangered and the smalleye hammerhead (Sphyrna tudes) and thesmooth hammerhead (Sphyrna zygaena)are listed as vulnerable on the IUCN Red List of Threatened Species™. Hammerheads use their wide heads to attack stingrays, pinning the winged fish against the sea floor. Dorsal spines (total): 0; Dorsal soft rays (total): 0; Anal spines: 0; Anal soft rays: 0. A large hammerhead with a notch at the center of head; 1st dorsal fin moderately high, 2nd dorsal and pelvic fins low. Olive-grey or dark grey above, white below (Ref. 5578). Fins nearly plain, dusky or blackish tipped.

Viviparous, placental, with 20 to 50 young per litter after a gestation period of 10-11 months. Size at birth between 50-60 cm TL. The female gives birth to 30 - 40 young

Summary of Distribution: Widespread in temperate and tropical seas. Western Atlantic: Canada to the Virgin Islands; Brazil to Argentina. Eastern Atlantic: British Isles to Côte d'Ivoire, including the Mediterranean. Indo-Pacific: South Africa to Sri Lanka; southern Siberia to Viet Nam; southern Australia, New Zealand, and Hawaii. Eastern Pacific: northern California, USA to Chile.
Note: Distribution range colors indicate degree of suitability of habitat which can be interpreted as probabilities of occurrence (fishbase.org)

Like the Scalloped Hammerhead, it is a good candidate for lighter tackle, and takes the same baits.