Marine Science 2016 Edition

Marine Invertebrates (1) Page 275 Exercise 11.2 Using a key A im To use a simple key to identify the major marine phyla. M ethod • Use the key below to identify the creatures to the right. • Note: This is not intended to be a key to all marine animals, but will enable the identification of most of the more common members of this kingdom. You may be able to find more complete keys and you will need to use these if you are to identify some rarer marine animals. M aterials • Photographs of marine animals or range of preserved specimens. • Key to marine life (see below). M ethod 1. Use the key to marine life below to classify the animals into Phyla. 2. When classified write down the structural characteristics particular to the animals. Key to marine life 1a. Body with no organs or mouth. Many small openings, fewer large openings. Spicules. Sponges (Phylum Porifera) 1b. Not as above ... Go to 2. 2a. Radially symmetrical. Tentacles with nematocysts Jellyfish, Corals, Anemones (Phylum Cnidaria) 2b. Not as above ... Go to 3. 3a. “Wormlike” shape, body divided into segments, bilaterally symmetrical. Segmented worms (Phylum Annelida) 3b. Not a “wormlike” shape ... Go to 4. 4a. Hard exoskeleton, jointed legs. Crabs, Prawns, Barnacles etc (Phylum Arthropoda) 4b. No exoskeleton (May be a shell) ... Go to 5. 5a. Radially symmetrical, tough spiny outer skin may be present. Sea Stars, Sea Urchins, Sea Cucumbers (Phylum Echinodermata) 5b. Bilaterally symmetrical ... Go to 6. 6a. Soft mucus covered body, possibly in a shell. Shellfish, Snails, Slugs, Squids etc (Phylum Mollusca) 6b. Backbone present, made of bone or cartilage. Fish, Reptiles, Birds, Mammals (Phylum Chordata)