Search results
Results from the WOW.Com Content Network
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 556 described and 23 undescribed species in eight orders. The families and genera within the orders are listed in ...
The use of sight probably varies with species and water conditions. The shark's field of vision can swap between monocular and stereoscopic at any time. [60] A micro-spectrophotometry study of 17 species of sharks found 10 had only rod photoreceptors and no cone cells in their retinas giving them good night vision while making them colorblind.
The shark's eyes are placed one on each end of this T-shaped structure, with their small mouths directly centered and underneath. Most hammerhead species are placed in the genus Sphyrna, while the winghead shark is placed in its own genus, Eusphyra. Many different—but not necessarily mutually exclusive—functions have been postulated for the ...
There are various types of sharks There are more than 400 shark species. And although most people are familiar with a few specific species, such as the great whites, there are all different types ...
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
Bodies of water in which sharks can be found include: Seas: all; Freshwater – some species of shark can live both in seawater and freshwater, and include: Bull shark; River shark; Sandbar shark; Depths: from the surface down to depths of 2,000 metres (6,600 ft). A whale shark in the Georgia Aquarium
These species of bigger, more-lengthy sharks can include great whites, bull sharks, big tiger sharks, great hammerheads, scalloped hammerheads, lemon sharks, spinner sharks, sandbar sharks and ...
Video above: Tail end of shark week celebrated at Shark Con. TAMPA, Fla. (WFLA) — Researchers have confirmed the existence of a new species of shark in South America.