INVERTEBRATES

Listen to the song and find out the characteristics of invertebrate animals:

INVERTEBRATES

They do not have a backbone.

We can classify invertebrates into six groups.

1-   ARTHROPODS

Arthropods have an external skeleton called exoskeleton.

 

                                                                                                                 1.4-insects- FLY

1.1-crustaceans-CRAB                         1.3-aracnid-SPIDER             They have three body parts:

They have two body                                             They have two body                                                  head, thorax and abdomen.

parts: cephalothorax and abdomen.                             parts: cephalothorax and abdomen                                   They have two antennae and three

Their exoskeleton is very hard.                                           They have four pairs of legs                                       Most have one or two pairs of wings.                    They have five pairs of legs                                                        and up to eight eyes.                                                                                                  

and four antennae.           

                                        1.2-myriapods-CENTIPEDE     

                                        They have long , thing, segmented bodies.

                                         They have many pairs of legs and two antennae.

  

2- MOLLUSCS

These are a big group of invertebrates. There are three subgroups.

 

     2.1 gastropod- SNAIL                                                 2.3 cephalopod-SQUID

                                        2.2. bivalves- MUSSELS

 

3-EQUINODERMS- STARFISH

           

                                              They live at the bottom of the sea.                                                          

  They are covered by  a hard, spiny skin     

 

4-SPONGES

                                                         

They live in water.

         They are very simple animals, they have no muscles,

          nervous system or circulatory system.

  

5-ANNELIDS-WORM

                

They have long, soft bodies with moist skin.                                         

Many annelids are parasites and live inside other animals.                    

They can live in water and on land.                   

    

6- CNIDARIANS JELLYFISH

Cnidarians live in the sea.

                  They have a soft, jelly-like body with one opening. This  opening is surrounded by venomous tentacles.