Page 40 - Fish and Amphibians (Britannica Illustrated Science Library)
P. 40

36 LIFE IN THE WATER                                                                                                                                                                                   FISH AND AMPHIBIANS 37




          The Best Disguise                                                                                                                                        Sharp Enough to Cut


                                                                                                                                                                   The sharp blades of the yellow tang's caudal
                o face their enemies, fish have developed a number of                                                                                              appendage look like scalpels. This fish can
                                                                                                                                                                   retract and extend its blades at will to hurt
                strategies to enable them to survive. Some of these                                                                                                potential attackers. The fish eats only algae;
          T are escaping, hiding in the ocean bed, or stirring up                                                                                                  it measures some 20 inches (50 cm) long.
          sand to avoid being seen. Other species have poison, and
          some can inflate and raise barbs or spines to discourage
          predators. In the oceans' depths are fish that have
          luminous organs that blind the enemy.




          Spot-Fin Porcupine Fish

          Like its relative the globefish, this fish  predator. This fish has another
          swallows water when it feels  defense mechanism: its modified
          threatened, swelling up to three times  scales act as barbs. When the fish's
                                                                                                                                                                                                   YELLOW TANG   This fish frequently
          its normal size. This makes it very  size increases, the scales extend                                                                                                                                 swims in schools
          difficult to fit inside the mouth of a  perpendicularly from the skin.                                                                                                                   Zebrasoma     with fish of other
                                                                                                                                                                                                   flavescens    species.
                       Spinal column
                                                     The spine
                                                     curves.

                Water   Stomach

          HOW IT INFLATES
          The water enters through the fish's                                                                                                                                                         Strange Garden
          mouth. The stomach stores water                                                                                                                                                             Garden eels can bury much of their body
          and begins to increase in size. The                                                                                                                                                         in the sandy seafloor and become stiff. A
          spinal column and the skeleton are                                                                                                                                                          group of buried garden eels looks like a
          flexible and adapt. If the fish is        The stomach                                                                                                                                       colony of algae or coral, even though their tiny
                                                    fills with
          taken out of the water, it can                                                                                                                                                              eyes are on the lookout for the small species
                                                    water.
          inflate in a similar way by                                                                                                                                                                 they eat. At the slightest sign of danger, they
          swallowing air.                                                                                                                                                                             go into their burrows.

                                                                                                                                                                                                                    The eel hardens its
                                                                                                                                                                                                                    muscled body and
                                                                                                                                                                                                Eels in a           buries its tail, leaving
                                                                                                                                                                                                group               its head in the open.
                                                                                                                                                                                                                    Walls covered with
                                                                                                                                                                                                                    mucus secreted by
                                                                                                                                                                                                                    the skin of the
                                                                                                                                                                                                                    animal's tail






                                                                                                                                                                                                             GARDEN EEL
                                                                                                                                                                                                             Taenioconger hassi
           At Rest                                                              Self-Defense                                                          STIFF SPINES
           The scales of the porcupine fish lie flat against                    Inflated porcupine fish can reach a diameter of up to 35              Modified scales, hard and resistant,
           its body, and its appearance is no different from                    inches (90 cm). This makes swallowing them impossible   SPOT-FIN      are found all over its body, except for
                                                                                                                                                      the tail. When these scales are
           that of any other bony fish. When it deflates                        for medium-size predators, which are frightened simply  PORCUPINE FISH  extended, it is almost impossible for a
           after an attack, it returns to its original state.                   by the porcupine fish's appearance.                     Diodon hystrix  predator to bite or swallow this fish.
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