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Any of more than 300 species of predatory cartilaginous fish (order Selachii).
An ancient animal, it has changed little in 100 million years. The skin typically is dull gray and tough and has toothlike scales. Most sharks have a muscular, asymmetrical, upturned tail; pointed fins; a pointed snout; and sharp triangular teeth. Sharks have no swim bladder and must swim perpetually to keep from sinking. Most species bear living young. Several species can be dangerous to humans (e.g., great white shark , hammerhead shark , sand shark , tiger shark ); smaller ones, called topes, hounds, and basking shark , mackerel shark , mako shark , thresher shark , whale shark .
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[c mediumvioletred] (as used in expressions)
basking shark
great white shark
white shark
{{link=hammerhead shark">hammerhead shark
mackerel shark
mako shark
nurse shark
sand shark
thresher shark
tiger shark
whale shark