Shark, bonnethead Sphyrna tiburo

Linnaeus, 1758

SPHYRNIDAE FAMILY
Also called shovelhead, cação-chapéu, cação-martelo, cação-pata, cornudo de corona.

This abundant species occurs in the western Atlantic form North Carolina, USA (occasionally to Rhode Island) to southern Brazil, including Cuba and the Bahamas, the Caribbean and the Gulf of Mexico. In the Eastern Pacific, it is found from southern California to Ecuador. It occurs chiefly in shallow water, often in bays, estuaries and channels where it feeds largely on crabs, shrimps and small fish.

The bonnethead differs from all other hammerheads in having a shovel or bonnet (not hammer) shaped head. Maturity is reached at about 30 in (75 cm) and it can grow to about 5 feet (150 cm). Pups are born in late summer and early fall with eight to twelve pups in each litter.

Bonnetheads can be taken on flies and are hard to beat as light tackle sportfish

Shark, whaler Carcharhinidae family

Includes 50 species; also known as requiem sharks, requins, cazones picudos, tiburones, tintorereas; some individual species … gray reef , narrowtooth, spinner, silky, Galapagos, bull, blacktip, oceanic whitetip, blacktip reef, dusky, Caribbean reef, sandbar, tiger, lemon, blue, whitetip reef, milk, sicklefin lemon

SPHYRNIDAE FAMILY


Whalers, or requiem sharks, all members of the genus Carcharhinus, are a group of closely- related sharks, which present identification difficulties. There are 12 genera and at least 50 species in this family, many with worldwide distribution and targeted by sportfishermen. Most are pelagic in tropical and warm temperate areas, a few are oceanic while at least one can penetrate far into fresh water. The most important identifying features are tooth shape and number, position of the dorsal fins, color and the presence or absence of an interdorsal ridge. Whales are typically viviparous, with a yolk-sac placenta (tiger sharks are an exception, being ovoviviparous). The Carcarhinidae family contains three of the four shark species most dangerous to humans.

Whalers are small to large sharks with fusiform bodies, round eyes, internal nictitating eyelids, ventrally placed mouths extending past the eyes, no nasoral grooves or barbles, usually no spiracles, moderately long labial furrows, small to large, more or less blade-like teeth in both jaws, often broader in the upper jaw, five gill openings, the fifth behind origin of pectoral fin. Two dorsal fins and an anal fin, the first dorsal fin moderate-sized to large and with its base well ahead of pelvic bases, the second dorsal fin usually much smaller than the first, precaudal pits present, caudal fin with a strong ventral lobe and lateral undulations on its dorsal margin. The intestine with a scroll-type valve and usually no color pattern.

All tackle records will be given to those positively identified to species level. Anglers submitting record applications should supply good lateral photographs of the shark, and photographs of the underside of the head and interdorsal area, the space between the first and second dorsal fins. At least six adjacent teeth taken from the center of the upper jaw would also aid in positive identification.

Shark, great hammerhead Sphyrna mokarran

SPHYRNIDAE FAMILY
Also called smooth or common hammerhead, scalloped hammerhead

The hammerheads occur worldwide, but some species have more restricted ranges. The most widely distributed species is probably the smooth, or common, hammerhead, Sphyrna zygaena. They inhabit shallow waters along the coasts, bays and harbors where the water is calm and the bottom sandy.

The eyes are located at the ends of two thin protrusions, resembling a hammer. The caudal peduncle lacks keels. Of the nine species of hammerhead sharks, the largest is the great hammerhead, S. mokarran, which may reach a length of 20 ft (6 m). Its head is T shaped, being almost straight along the front edge and notched in the center. Another large species, the smooth hammerhead, S. zygaena, grows to 14 ft (4 m). The front edge of its head is rounded and unnotched in the center. The scalloped hammerhead, S. lewini, grows to 10 ft (3 m). The front edge of its head is rounded and notched. Of the lesser known hammerheads, there is S. couardi, a large West African species that resembles S. lewini, and the strange looking S. blochii, whose head lobes often measure 50 percent of the body length and are swept back like the wings of an airplane. The remainder of the species, S. tiburo, S. media, S. corona and S. tudes, known as the bonnetheads, are only 3 6 ft (1 2 m) long and have very short lobed, shovel shaped heads.

It swings its broad, flat head back and forth over the bottom in a scanning pattern, in the same way as one uses a metal detector. Tiny organs called the ampullae of Lorenzini, located in the head, function as electro-

-receptors that enable the shark to detect food buried beneath the sand. Stingray are a favorite food. According to scientist Perry Gilbert one large hammerhead was found to have 96 stingray barbs imbedded in its jaw, mouth and head.

Hammerheads fight hard making long surface and midwater runs and thrashing about causing a great deal of commotion. Fishing methods include slow trolling, drifting or still fishing with chum and baits that are oily or bloody. Mackerel, jack, squid and other baits, as well as artificial lures, may also work on occasion.

They are viviparous and giving birth to as many as 30 or 40 young at a time. Some are known to be man eaters. In fact, the first fatal shark attack recorded in American waters was by a hammerhead off Long Island, New York in 1815. The meat of the hammerhead is of good quality if fresh and properly prepared. The fins are used in soup in some areas.