Page 203 - Dive the Seas and More-2

Coral Reef Teacher’s Guide

EXAMPLES OF PROTECTIVE STRATEGIES: symbiotic relationships: coral - zooxanthellae, sea

Blue Dash Butterflyfish: The blue dash but- anemone - clownfish, or cleaner wrasse - fish being
terflyfish is shaped like a thin pancake so that cleaned, and discuss the energetic, ecological, and
it can hide easily among the coral and be safe survival benefits for each of the organisms involved.
from predators. It is bright yellow with a blue Have the class break up into small groups and
streak on its body and a “fake eye” on its tail pre- pare a short poem, role playing presentation,
to confuse any predators that try to attack. or artistic representation about the importance of
The predator thinks that it is aiming for the sym- biosis on the coral reef. As an extension have
head when in reality it is aiming for the tail, each student prepare a research essay describing
enabling the butterflyfish to dart forward and a sym- biotic relationship and its evolutionary and
escape. ecologi- cal importance to the organisms involved.
Clown Triggerfish: The clown triggerfish is
marked with large white polka dots which EXAMPLES OF SYMBIOSIS:
help to break up its outline and camouflage Corals and zooxanthallae: Within the tissue of
it against the reef. It is also very poisonous the coral polyp live many microscopic algae called
so predators do not try to eat it. The clown zooxanthallae. These algal cells provide the coral
triggerfish attacks small reef animals, such as with food through the process of photosynthesis in
fish that hide in the sand and sea urchins, which zooxanthallae cells use sunlight to convert
by blowing streams of water out its mouth to the carbon dioxide and water in the polyp tissue
uncover or overturn its prey. into oxygen and carbohydrates. The oxygen is used
Hard Coral: Hard corals build reefs by secret- by the polyp for respiration and the carbohydrates
ing a hard external limestone skeleton. During are used for energy to build its limestone skeleton.
the daytime, the coral polyp retracts into its In return, the polyp provides the zooxanthallae with
limestone base for protection from hungry fish nutrients, protection, a place to live, and carbon di-
but at night it comes out to feed on floating oxide, a by-product of respiration which is vital for
plankton. photosynthesis.
Nudibranch: The nudibranch feeds on the Sea anemone and clownfish: The clownfish has
tentacles of sea anemones but does not trig- a sym- biotic relationship with its partner, the sea
ger their stinging cells (called nematocysts). anemone. The clownfish hides among the anem-
Instead, the stinging cells migrate to the nu- one’s poison- ous tentacles, safely protected from
dibranch’s exposed gill where they serve as a predators. It is believed that the mucus coating on
defense against predators. Nudibranchs come the clownfish protects it from the stinging cells in
in a wide variety of shapes and bright colors. the sea anemone’s tentacles. In return, the clown-
Their bright colors warn predators of their fish, be- ing extremely territorial, drives off any fish
deadly poison. that try to prey on the anemone. The clownfish also

Pufferfish: Pufferfish protect themselves by drops bits of food among the tentacles which the
drawing water into their abdomen to inflate anemone can eat.
themselves to more than twice their normal Cleaner wrasse and fish being cleaned: The clean-
size thereby making it difficult for predators to er wrasse cleans debris and parasites off of larger
swallow them. They also have large protrud- fish which keeps the larger fish healthy and gives
ing eyes that can see in all directions enabling the cleaner wrasse nourishment and protection.
them to spot predators quickly. Pufferfish pro- The fish being cleaned will allow it to move freely
duce a powerful poison called tetraodontox- about its gills and mouth without trying to eat it.
in which discourages predators from eating In some places fish actually line up for this service,
them. forming cleaning station.
Stonefish: The stonefish uses more than one method for
protection: camouflage to blend in with its en- viron-
ment, and lethal poison in its dorsal spine to avoid being
eaten. It is reported to be the most deadly venomous fish
in the Indo-Pacific region.

H‐15