Sem 2 Week 6 Compare and Contrast of 3 Invertebrates

Sea cucumber
Kingdom: Animalia
Phylum: Echinodermata
Class: Holothuroidea



Sea cucumber, picture: http://library.thinkquest.org/J001418/media/seacuc.JPG



Cuttlefish
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda



Cuttlefish, picture: http://a-z-animals.com/media/animals/images/470x370/cuttlefish3.jpg



Crayfish
Kingdom: Animalia
Phylum: Arthropoda
Class: Crustacea



crayfish, picture: http://www.biol.andrews.edu/everglades/organisms/invertebrates/arthropods/pond_crayfish/pond_crayfish_main.jpg


Similarities:
- All three invertebrates live in an aquatic environment.
-All three invertebrates have some form of defense mechanism against predators.
- All three invertebrates are able to move around, not attached to the ocean floor or rock like a polyp.

Differences:
- The crayfish is hard shell (has an exoskeleton).
- The sea cucumber has a layer of spiny skin, used for protection.
- The cuttlefish has tentacles for locomotion and feeding.