Invertebrates

Invertebrate animals have not internal skeleton. Many invertebrates have an exoskeleton. Invertebrates are the biggest group of animals on Earth. Invertebrates can be classified into six groups. Most of them are oviparous animals (they are born from eggs).

Sponges

They are the simplest invertebrates. They live in the sea. They can not move around. Their bodies look like a sack.

Echinoderms

They all live in the sea. They have their body coveredby hard plates and spines.

Cnidarians (Jellyfish, anemones & corals)

They all have soft bodies and tentacles.

Corals live in groups and they look like plants.

Annelids (worms)

They have a long and soft body.

Molluscs

They have a soft body. Nearly all of them have shells to protect their body.

Most of them live in the water.

Arthropods

They have their body covered by an articulated shell, called exoskeleton. They bresthe through tracheas if they live on land, and they breathe through gillls if they live in the water.

Science 5th-6th

INVERTEBRATES

Invertebrate animals have not internal skeleton. Many invertebrates have an exoskeleton. Invertebrates are the biggest group of animals on Earth. Invertebrates can be classified into six groups. Most of them are oviparous animals (they are born from eggs).