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Shark migration patterns may be even more complex than in birds, with many sharks covering entire ocean basins. Sharks can be highly social, remaining in large schools. Sometimes more than 100 scalloped hammerheads congregate around seamounts and islands, e.g., in the Gulf of California. [39] Cross-species social hierarchies exist.
The first shark-like chondrichthyans appeared in the oceans 400 million years ago, [1] developing into the crown group of sharks by the Early Jurassic. [2] Listed below are extant species of shark. Sharks are spread across 512 described and 23 undescribed species in eight orders. The families and genera within the orders are listed in ...
Ben Cropp – Australian former shark hunter, who stopped in 1962 to produce some 150 wildlife documentaries; Richard Ellis – American marine biologist, author, and illustrator. Rodney Fox – Australian film maker, conservationist, survivor of great white shark attack and one of the world's foremost authorities on them
Ferreira describes the four encounters with the giant shark he participated in with great detail in his book Great White Sharks On Their Best Behavior. [79] One contender in maximum size among the predatory sharks is the tiger shark (Galeocerdo cuvier). While tiger sharks, which are typically both a few feet smaller and have a leaner, less ...
Welcome to the shark portal! Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha (or Selachii) and are the sister group to the Batoidea (rays and kin).
Sharks are split into eight orders: Carcharhiniformes: ground sharks, the largest order of sharks, including requiem sharks, catsharks, swellsharks, houndsharks, weasel sharks and hammerheads; Heterodontiformes: bullhead sharks; Hexanchiformes: cow sharks and frilled sharks; Lamniformes: mackerel sharks, including thresher sharks
The whale shark (Rhincodon typus) is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of 18.8 m (61.7 ft). [8] The whale shark holds many records for size in the animal kingdom, most notably being by far the most massive living non-cetacean animal.
The river sharks (of the genus Glyphis) can live in both saltwater and freshwater as well, while one of their members, the Ganges shark (Glyphis gangeticus), lives exclusively in freshwater. Some prehistoric sharks (in a broad sense), including hybodonts and xenacanths , are also thought to have inhabited freshwater environments.