AASHARKS.COM
( All About Sharks )
|
Choose a Category Below
|
Sand Tiger SharkThreat Level: low/medium
Scientific name...........Carcharias Taurus Family name..............Odontaspididae Other Common names..........Gray nurse shark and Ragged tooth shark
Depending on where you are in the world, the sandtiger shark may be known as the spotted ragged tooth or gray nurse shark. It is one of four species belonging to the sand tiger family, a group of large, fearsome looking sharks that swim slowly with their mouths open. Their bodies are stout, with two large dorsal fins. The elongated tails have a long upper lobe; there is a precaudal pit but no caudal keels. The sand tiger shark has a short, flattened snout. Its dorsal fins are about equal in size, with the first located closer to the pelvic fins than to the pectoral fins. Long gill openings in front of pectoral fins.
Pups are born measuring 3.1 to 3.8 feet long, males mature at 7.2 feet and females at 7.2 to 9.4 feet. Sand tiger sharks can grow to a maximum length of 10 to 12 feet.
There are three rows of large slender pointed teeth on each side of the midline of the upper jaw.
It is bronzy above, gradually becoming paler below. Juveniles have reddish or brownish spots scattered on the tail and rear of the body, which tend to fade with age.
Their diet consists of many species of large and small bony fishes, small sharks, rays, crustaceans, and squid. Most of its prey are swallowed whole, rather than bitten into pieces, not surprising considering the grasping, rather than cutting teeth of this shark.
They are a slow but strong swimmer, more active at night. Air swallowed at the surface and held in stomach provides neutral buoyancy, enabling the shark to hover in the water. Complex social, courtship and mating behaviour studied in captivity and the wild. May aggregate in schools of 20-80 for feeding ( observed to herd prey fishes ), courtship, mating and birth. Some are highly migratory, moving to cooler water in summer.
Sand tiger sharks are found in Western Atlantic, eastern Atlantic, western Indian Ocean and western Pacific. Occur in shallow bays, sandy coastal water, and rocky or tropical reefs from shallow waters down to about 655 feet. Divers often find large numbers in aggregations around rocky outcroppings in offshore waters.
These sharks are oviphagous, In each of the two uterine chambers, the first embryo to hatch, at about 6 inches, kills and devours the other developing siblings. The two embryos continue to feed on the other eggs inside the separate uterine chambers. After the gestation period of eight to nine months, the two live young are born, about 3 to 3.8 feet long.
Essentially gentle sharks, they usually become aggressive only if provoked.
|
copyright . AA Sharks is owned and operated by 'C26 Web Marketing'