Foods and Feeding 137
them were attacked at the same rate as fishermen without masks. It’s sort of
like seatbelts and bike helmets: having one doesn’t help much if you don’t
use it properly. (In case you’re wondering, no one has tried painting faces
on the backs of sea turtles as a test.)
Some sharks specialize on, or at least prefer, certain food types. Carcha-
rhinid Tiger, Bull, and Galapagos sharks are well known for eating other
sharks but are by no means the only ones that do so. Sevengill Sharks have
been seen attacking a number of other, smaller sharks, including Leop-
ard Sharks in California and School Sharks in Africa. Sevengills are also
cannibalistic. Again, surprising their prey appears to be a tactic of choice
for Sevengills. A seemingly sluggish animal, a Sevengill moving slowly and
showing no obvious interest in several Leopard Sharks will put on a sudden
burst of speed and quickly grab a Leopard Shark, bypassing other, closer
Leopard Sharks.
Large hammerheads, such as Great Hammerheads, feed heavily on
stingrays. Bull sharks also favor stingrays. Bonnetheads, the smallest ham-
merhead species, prefer swimming crabs. Sleeper and Cookiecutter sharks
take chunks out of marine mammals such as seals and dolphins, although
Sleeper Sharks also feed on the ocean’s largest invertebrates, the giant
and colossal squids. Leopard Sharks, Nurse Sharks, and Green Lantern-
sharks (Etmopterus virens), as well as most skates and rays, feed mostly on
invertebrates. Horn Sharks feed preferentially on mollusks such as clams
and have the dentition needed to crush hard-bodied prey. Stingrays as a
group also possess crushing dentition and often feed on animals with shells.
Tiger Sharks are well known for
their extremely diverse diets, which
include live prey, dead animals, and
discarded human trash of all kinds.
Photo by Austin Gallagher, http://austin
gallagher.com; used with permission