154 Sharks: The Animal Answer Guideacute sense of smell, would find it, not to mention a host of scavenging
crabs, bristle stars, snails, and other fishes.Must a shark turn on its back to feed?
No. Although some sharks will turn on their sides or even their backs
to feed, they don’t have to. Sharks approach food at the surface and under-
water head-on, swim over it, and then bite. Because their snout is slightly
hinged and their upper jaw can be protruded (stuck out), sharks lift their
snout to bite at things directly in front of them. We can’t do that; we can
only drop our lower jaw when we bite something.Do sharks cooperate with one another to feed?
Cooperative feeding requires both intelligence and sociality. In killer
whales, humpback whales, lions, and wolves, individuals do coordinate their
movements, with different individuals playing different roles. Additionally,
individuals must show restraint during the initial stages of attack. Other-
wise, prey recognize the intent of the predators and invariably escape.
Cooperative feeding in bony fishes is rare, limited to Sailfish, Bluefin
Tuna, pompanos, and lionfish. Getting into the water to watch sailfish feed
actively is exciting and a little scary. Exposing oneself to actively feeding
sharks is downright dangerous and observations are few.
At least three species of sharks have been observed feeding coopera-
tively. The best known of these, for which repeated observations exist, is
the Broadnose Sevengill Shark. Sevengills are solitary predators on smaller
prey such as fishes and other sharks. But when attacking large prey capable
of defending themselves, such as Cape fur seals (Arctocephalus pusillus pusil-
lus), which can weigh 350 kg (770 lb), they attack in groups. In a typical
attack sequence, a dozen or so Sevengills approach a fur seal at the surface,Nurse Sharks feed on a variety of
hard-bodied prey and have teeth
specially adapted for crushing rather
than biting. Each tooth is flattened
and has a rounded tip, which means
that when the jaws are brought to-
gether, the teeth grasp and crush
at the same time. Photo courtesy of Phil
Motta
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