Animals: Mollusks, Annelids, Echinoderms & Arthropods
The Mollusks 23% of marine animals Characteristics: Radula Rough tongue used to scrape food off surfaces Muscular Foot Internal Organs Live on land, marine and fresh water
Bilateral Symmetry Mollusks have bilateral symmetry Have left and right sides Left and right sides are a mirror image of each other Have Dorsal (top) and Ventral (bottom) sides
Gastropods Name means “Stomach Foot” Snails and Slugs Many have a shell Move using a large, muscular foot Largest (land)-Giant African Snail
Bivalves Name means “Two Shells” Clams-dig down into the sand Scallops-lie on surface and move around by shooting water Oysters-cement their shells to rocks
Cephalopods Name means “Head Foot” Octopus & Squid Have tentacles with suction cups Use a beak to tear at food Use ink to escape predators
Echinoderms Name means “Spiny Skin” Characteristics: Radial Symmetry Several arms Have 5 body segments Each has duplicate sets of organs Move using tube feet
The Annelids Characteristics: Worms with clear body segments Bilateral Symmetry Closed circulatory system One-way digestive system Nervous system Live on land, fresh & marine water
Annelid Anatomy
Arthropods Make up 90% of the Animal Kingdom Characteristics: Exoskeleton Body divided into sections Jointed legs Bilateral Symmetry
Crustaceans Characteristics: 2 Body Segments 2 sets of antennae 5 or more leg pairs Mostly aquatic
Centipedes Characteristics: Well defined head One pair of antennae One pair of legs per body segment Flattened body
Millipedes Characteristics: Well-defined head One pair of antennae 2 pairs of legs per body segment Cylindrical Body
Arachnids Characteristics: 2 body regions 8 legs No antennae Moving mouth parts
Insects Characteristics: 3 body regions 6 legs attached to middle body segment 2 antennae Large compound eyes Some have wings attached to middle body segment