Page 132 - Dive the Seas and More-2

Coral Reef Teacher’s Guide Life on the Coral Reef
CORAL REEF LIFE CARDS (453kg). Humans have destroyed populations

of these clams in the Pacific, harvesting them
FACT SHEET for their meat and shells. Projects are now un-
derway to farm giant clams and return them
to the reefs.
FOR USE BY THE TEACHER. Gray Reef Shark - The gray reef shark hunts
for food along the coral reef during the night
Blue Dash Butterflyfish - The butterflyfish is and rests in caves during the day. Sharks are
shaped like a thin pancake so that it can hide powerful carni- vores, hunting large and small
easily among the coral and be safe from pred- marine animals including fish, crustaceans,
ators. The blue dash butterflyfish is bright yel- and mollusks. Some of the larger species even
low with a blue streak on its body and a “fake hunt marine mammals, sea birds, sea turtles,
eye” on its tail to confuse any predators that and other sharks. Sharks have very sharp
try to attack. The predator thinks that it is teeth, keen vision, and a highly-devel- oped
aiming for the head when in reality it is aiming sense of smell. Although they are at the top of
for the tail, enabling the butterflyfish to swim the food chain, most sharks are not dangerous
forward quickly and escape.
to humans unless provoked.
Clown Triggerfish - The clown triggerfish is Hard Coral - Hard coral builds reefs by secret-
marked with large white polka dots which ing a hard external limestone skeleton. There
help to break up its outline and camouflage are three types of hard (stony) corals: branch-
it against the reef. It is also very poisonous ing, massive and plate. Most hard coral polyps
so predators do not try to eat it. The clown have tentacles in multiples of six and can be
triggerfish attacks small reef animals, such as found individually or in colonies. During the
fish that hide in the sand and sea urchins, by daytime, the hard coral polyp retracts into its
blowing streams of water out of its mouth to limestone base for protection but at night it
uncover or overturn its prey.
comes out to feed on floating plankton.
Clownfish and Sea Anemone - The clown- Hawksbill Turtle - The hawksbill turtle is a
fish, a small orange damselfish often marked species of sea turtle with its nose shaped like
with one or two white stripes, has a symbiotic the sharp beak of a hawk. Most sea turtles are
relationship with its partner, the sea anem- herbivores (vegetarians) feeding on seagrass.
one. The clownfish lives among the stinging Many lay their eggs in nests on the beach. Sea
tentacles of the anemone. The fish protects turtles are endan- gered because many of them
the anemone from being eaten by predators are caught and drowned in fishing nets each
and drops bits of food into its mouth, and the year, their eggs and flesh hunted for food, and
anemone protects the clownfish with its poi- their shells and skin used for ornament.
son- ous tentacles.
Lionfish - The lionfish has spectacular orange
Damselfish - Damselfish come in many colors, and white markings which help to camouflage
from dull brown and gray to brilliant yellow it from predators, however the spines on its
and blue. They are found abundantly on the fins are highly poisonous. Lionfish are most-
reef and are very territorial. Some species are ly stationary during the daytime but active at
“farmers”, actively guarding and growing small night, feeding primarily on crustaceans and
patches of algae on an area of coral to serve as small fish. Because of its beauty and unique-
a food source.
ness, it is often photographed by divers.
Giant Clam - The giant clam has a symbiotic Mollusk - The mollusk is an animal with anun-
relationship with its zooxanthellae, enabling it segmented muscular “foot” that is protected by
to grow its own food in the tissue of its man- a shell. This is a giant triton, the natural pred-
tle. It can reach more than 40 inches (1m) in ator of the crown-of-thorns sea star which eats
length and weigh more than 1,000 pounds
coral polyps. The triton has been overharvest-

E - 20