Sea cucumbers
There’s a sea animal that looks like a vegetable, gets its food by
\”licking its fingers,” and shoots out part of its insides if it is
attacked!
Because this animal looks like the vegetable called a cucumber, it
became known as a sea cucumber. At one end of its body is a mouth
surrounded by a ring of tentacles. The tentacles may look like bunches
of leaves or flowers.
There are about five hundred different kinds of sea cucumbers. They
don’t all look alike or get their food in quite the same way. One kind,
called the \”shaggy dog,” looks somewhat like a long cactus plant with
stubby spikes all over it. Another resembles a many-colored vase with a
bunch of small blue and white flowers in it.
One kind of sea cucumber has a flat body with rows of long, pointed
\”horns” on its sides and back. Another looks much like an octopus. And
some look like worms. Sea cucumbers come in all sizes. They range from
about three inches (7.5 centimeters) to nearly seven feet (2.1 meters)
in length.
Most sea cucumbers search for food by creeping along the sea bottom on
rows of little tube-shaped feet. They catch their food with their
tentacles. The tentacles are sticky, and tiny plants and animals stick
to them. Then the sea cucumber pokes each tentacle into its mouth and
sort of licks the plants and animals off—just as you might lick jam
off your fingers.
Other kinds creep through the mud, just as earthworms dig their way
through soil. Like earthworms, these creatures eat the mud to get bits
of dead plants and animals that are in it. Some sea cucumbers bury
themselves in mud, with only their tentacles sticking out to catch food
in the water.
Sea cucumbers are slow and helpless. But they do have an amazing way of
defending themselves. They turn themselves partly inside out and spit
some of their insides at their enemy! While the enemy stops to feed on
this mass, the sea cucumber has time to crawl away. In about six weeks
it will grow new insides!
One of these sea cucumbers is stretched out to its full length. The
other, at the bottom of the picture, is curled into a ball.
The scaly skinned creatures we call snakes, lizards, turtles,
crocodiles, and alligators are all reptiles [(rehp]{.smallcaps} tuhls).
Hundreds of millions of years ago, reptiles ruled the earth. They
started out as land animals, and most are still land animals.
Long ago, however, a number of reptiles became sea dwellers. There are
now snakes and turtles that spend their whole lives at sea. They
wouldn’t be able to exist on the land. Yet, because their ancestors were
land dwellers, these sea-going reptiles are still tied to the land in
several ways.
For one thing, unlike fish and most other ocean animals that can breathe
in water, reptiles are air breathers. Even though the sea is their home,
they can drown in it!
For another thing, most reptiles lay eggs with shells. But an egg with a
shell is designed to be laid on land. It would sink in water. So the
sea-going reptiles that lay eggs must come onto the land to lay their
eggs.
But in all other ways, the sea reptiles are creatures of the water. They
are as much at home in the water as a fish.
