This order of three families and more than 80 species features sharks with
cylindrical bodies bearing two dorsal fins (some with spines), no anal fin, and
long snouts. Both jaws in many species have strong cutting teeth in short
mouths. Dogfish sharks live in all oceans, reaching depths of almost 20,000
feet. All species hatch young from eggs within the body.
Appearance: Large sharks with stocky, cylindrical bodies and widely arched
mouths. Their first dorsal fin lies over the pelvic fins.
Size: The bramble shark reaches a length of over 10 ft, and the prickly shark
grows to about 13.2 ft.
Habitat: Both species mainly dwell in deepwater slopes. They range down to
almost 3,000 ft but occur on the shelves in water as shallow as 36 ft.
Distribution: The bramble shark ranges widely in temperate and tropical seas.
Currently, the prickly shark is known only as a Pacific Ocean dweller.
Diet: Bony fishes, other smaller sharks, octopuses, squid, crabs and eggcases
of sharks and chimaeras.
Shark bite: Prickly sharks have been observed suspending themselves
almost motionlessly just off the sea bottom. The reason for this hovering
behavior is unknown.
Appearance: A diverse group which ranges from very small to gigantic. They have
stout to slender bodies, variably sized spiracles, and mouths ranging from
broadly arched to transverse. The first dorsal fin is in front of the pelvic
Size: Some dogfish sharks reach six to eight inches and are among the smallest
of living sharks; many reach between 12 and 36 in; the giants of the family,
the Greenland and Pacific sleeper sharks, many reach 23 ft in length.
Habitat: Most dogfish sharks are found on or near the bottom on temperate to
tropical continental and insular slopes. Some occur on the continental shelves;
a small number of species are oceanic.
Distribution: Probably a greater range than any other shark family. Different
species are found in all seas from the Arctic to the sub-Antarctic.
Diet: Bony fishes, other sharks, cephalopods, crustacea, and other
invertebrates. Larger members of the family also eat marine mammals.
Shark bite: The piked dogfish shark weighs in water only 2.7 percent of what it
weighs in air.
Appearance: Small, strange-looking sharks with highly compressed bodies, rough
skin, small to large spiracles, transverse mouths with lip papillae, strong
dorsal fin spines, and a first dorsal well in front of the pelvic fins.
Size: Most grow to less than 3.3 ft, though one species sometimes reaches
almost 5 ft.
Habitat: Upper continental and insular slopes and outer shelves at depths of
between 13 and 2,375 ft.
Distribution: Temperate and tropical seas.
Diet: Bottom invertebrates and small fishes.
Shark bite: Roughsharks rely on their expanded body cavities and large oily
livers to attain neutral buoyancy, so they can hover and swim without needing
forward motion for lift.
Cocos Island |
World of Sharks |
Site Map |
Editor's Picks |
Previous Sites |
Join Us/E-mail |
TV/Web Schedule |
Watch NOVAs online |
Site Map |
PBS Online |
NOVA Online |
© | Updated June 2002