Sea Monsters (5 page)

Some octopuses can unscrew caps from bottles. An octopus named
Frida lived in
a German zoo. By watching her keepers, Frida learned to open a can of shrimp. She even put on a “can opening” show for visitors.

Some octopuses seem to play in the bubbles coming from air tubes in their tanks. One octopus spread her mantle and “surfed” on the tide of bubbles!

Octopuses live in dens under rocks or in cracks on the ocean floor. For protection, they pile rocks outside the openings.

One scientist watched an octopus catch some fish. Before eating, the octopus shoved rocks up in front of itself to make a fort. Then it settled down to eat.

Octopuses lay eggs in their dens and tend them for up to six months until they
hatch. The
giant Pacific octopus lays over 57,000 eggs! Each egg is the size of a grain of rice. Out of all these eggs, only a few will survive.

Octopuses trick their enemies by quickly changing their skin color. They turn the same color as the background. When an animal’s skin matches its background, we say it is using
camouflage
(KAA-muh-flahj).

When octopuses are in danger, they shoot a stream of black ink into the water. The ink clouds up the water. It stings predators’ eyes and confuses their sense of smell. The octopus turns white and slips away. The predator thinks it is still hiding in the cloud of ink.

Octopuses are
nocturnal
(nok-TUR-null) hunters. This means they mainly hunt at night.

Octopuses eat fish, lobsters, clams, snails, crabs, turtles, shrimp, and scallops. If an animal has a hard shell, the octopus bites it with its beak to try and open it. Sometimes it will bite right through the
shell. Then the octopus shoots out a poison that stuns its prey. Soon the muscle that holds the shell together dissolves, and the octopus can tear it apart.

At the
Seattle Aquarium,
sand
sharks lived in a large tank with other animals. There was one problem. Their keepers kept finding the sharks’ dead bodies at the bottom of the tank. No one could figure out why. To solve the mystery, they put a video camera in the tank.

The camera showed a shark swimming around. Suddenly a
giant Pacific octopus attacked from behind a rock. The octopus wrapped its arms around the shark and held it in a deadly grip. Even though the shark struggled, it was no use. The next day, there was another dead shark in the tank.

The female
blanket octopus grows to over six feet long. Recently divers off the coast of Australia captured a live male blanket octopus. Male blanket octopuses are almost never seen. That’s because they are just under an inch long! That’s as big as a walnut.

This tiny male defends himself with weapons! He grabs two
tentacles from a
passing
jellyfish. When predators approach, he waves the stinging tentacles in their faces! Whoaaa! Back off, buddy!

Imagine diving around a coral reef. Suddenly a huge creature appears overhead. The monster has two large black wings that flap as it moves. It also has horns and a big, long mouth.

This animal is not really a monster. It is a manta ray, or devilfish. Manta rays can
reach sixteen feet in length and weigh over two tons. As they swim, their wings gently flap up and down. The wings are actually fins.

Manta rays’ bodies are shaped like diamonds. Their shape helps them glide easily through the water. Manta rays swim with their mouths open to catch any
plankton
floating by. Their horns push the plankton toward their mouths.

Even though manta rays look scary, they are not poisonous. They are called “devilfish” only because of their horns.

Stingrays are close relatives of manta rays. Stingrays are only about two feet long. They have poisonous, sharp barbs on their tails. Because stingrays are flat, they can hide easily beneath the sand.