- Although the flesh of the almaco jack is considered quality table fare, the species has been associated with ciguatera poisoning, a seldom fatal stomach irritation.
- The almaco jack is susceptible to tapeworm parasites in the caudal peduncle area, but the meat can be eaten safely if affected portions are cut away.
Scalloped hammerhead shark (Sphyrna)
The most unique physical characteristic of the scalloped hammerhead shark is the oddly shaped head for which they are named. Scalloped hammerhead sharks have the two long lobes extending from the head that are common with all hammerheads but they also have a large indentation in the center of the head from which they get the moniker “scalloped.” Coloration is brownish gray or olive-gray on the back and side, shading to grayish white on the belly. The pectoral fin may be tipped with gray. They are fast and agile swimmers, feats aided by elongated bodies and head shape. The dorsal fin is tall, though not as tall as that of the giant hammerhead, and the top lobe of the tail fin is 3 to 4 times longer than the bottom lobe. The mouth is relatively small.
Scalloped hammerhead sharks occupy warm coastal waters and tropical seas and inhabit both sides of the Atlantic and Pacific Oceans, as well as in the Indian Ocean. In the Western Hemisphere they are present from New Jersey to Brazil in the western Atlantic, including the Gulf of Mexico, and from southern California to Ecuador in the eastern Pacific.
Scalloped hammerhead sharks are both an inshore and offshore species. When inshore they often gather in large groups around seamounts and reefs. They will also be found in bays, the surf of beaches and tidal shallows. Offshore they are found over the continental shelf and the adjacent deep water up to 900 feet deep. Preferring warm water, scalloped hammerhead sharks are rare in waters at temperatures below 72 F. Although known to form large schools that migrate with the seasons, permanent resident populations also exist.
� At one time the U.S. Navy listed the hammerhead sharks as the third most dangerous shark after great whites and tiger sharks. Now the list reads great white, bull, then tiger shark. Experts believe any hammerhead shark attacks on humans are defensive in nature.
� Female scalloped hammerhead sharks have a unique ritual for establishing dominance amongst themselves: an individual performs a “corkscrew” spin, then flips over, exposing their white underside. Biologists speculate that the glare from light reflecting off the skin causes other females to cower.