Name _____________________________________

Invertebrate Worksheet

1. Approximately what percentage of animals are invertebrates?

2. What are invertebrates?

3. Name the phyla of invertebrates and members of each phyla.

Sponges

4. _____________ are in the phylum Porifera. There are _____ different

classes & most of these are ____________ organisms found in oceans &

seas. A few sponges are found in ___________ ____________, but

these are small and not brightly colored.

5. Sponges are _____________ ________________that trap

__________ from water as it flows through them. But some are

_______________, meaning that they can catch and eat live organisms.

6. Sponges have no basic body arrangement and are said to be ________________.

7. Sponges live attached to one spot as adults so they are ____________;

but the ____________ are ciliated, free-swimming creatures.

8. The skeleton of sponges is made of a flexible protein called

___________ and hard fibers called __________ which are composed of

calcium carbonate or silica.

9. Sponges are full of holes called __________ through which water flows

into their __________ bodies.

10. Sponges are the simplest animals and have neither a _______________,

________________, nor ________________ system. Nor do they have

________________ or even well-defined _________________. However,

sponges do have specialized _________ in their bodies.

11. Special cells called choanocytes (_____________ ___________ ) line

the inside of the sponge’s body and have _____________ and small

tentacles that spin to pull in water.

12. __________cells form the outer layer of the sponge’s body and capture

plankton from the water.

13. _______________ are special cells that digest or store this food.

14. Wastes are removed from the cells through the simple process of

______________ and excess water leaves a sponge through a large opening

at the top called the __________.

15. Sponges can reproduce sexually, or if a mate is not available, they can

reproduce asexually by __________ OR by _______________, whenever a

piece of a sponge breaks off. This last method helps sponges form

_____________.

16. When producing sexually, sponges can make both types of gametes (eggs

and sperm). Because of this, sponges are said to be ________________.