The New Childrens Encyclopedia

Invertebrates

There are thought to be 5 million species

of invertebrate roaming the planet—

that’s 95 percent of all animal life on

Earth. They are the world’s most

successful animals and can be found

on land, in the sea, in the air, and even

inside your body!

LIVING WORLD

WHAT IS AN INVERTEBRATE?

Animals without backbones are called

invertebrates. They have no internal skeleton;

instead, some have an exoskeleton (a hard outer

cover, like a crab or a beetle), some live inside a

shell (such as snails and clams), and some are

divided into soft segments (such as worms).

New clothes, please!

Exoskeletons don’t

grow even when the

body inside them

does. So as an

invertebrate gets

bigger, it needs to

shed its shell

and make a

new one.

There is a huge variety of invertebrate.

The differences lie not just in the way they look, but

also in their behavior and even the way they move.

 SPONGES

are invertebrates

of the simplest

kind: they don’t

even have a

head or a

brain...

... Yet octopuses are very

intelligent. A female in

captivity learned to

open jars by copying

her keeper.

 ANTS are social

animals that work

together for

survival...

... But tarantulas

live and hunt

alone.

 CORAL looks

like a plant

and barely

moves,

rooted to the

seabed...

... But

monarch

butterflies

can fly

2,500

miles

(4,000

km) on

migration

every

year.

TAKE A LOOK

In addition to no

backbones, invertebrates

also have no true jaws.

Garden

snail

Earthworm

Tenebrionid beetle

110

Crab with

pincers raised