Invertebrates Eight Major Phyla

Phylum Porifera Poriferans/Sponges Contains many pores Grows back together if cut or chopped up

Phylum Porifera Poriferans/Sponges Sexual and asexual reproduction Made of spicules

Phylum Cnidaria Cnidarians Hollow, central body cavity with only one opening (cup shaped) “tube within a tube” Nematocysts – special stinging structures around the mouth

Phylum Cnidaria Cnidarians Sexual and asexual reproduction radial symmetry

Phylum Platyhelminthes Flatworms Flat bodies Regeneration – grows part back digestive tract is tube

Phylum Platyhelminthes Flatworms Live in ponds and streams, bottom of plants or rocks Some live in animal or human host, others are freeliving

Phylum Nematoda Roundworms                                                                               Resemble strands of spaghetti Live on land or in water Can be parasites

Phylum Nematoda Roundworms Have both a head end and a tail end with a digestive tube for food entrance and exits

Phylum Annelida Segmented worms Ringed Body is divided into several rings or segments – at least 100

Phylum Annelida Segmented worms Setae – bristles that help the worm to move Earthworms’ wastes enrich soil

Phylum Arthropoda Largest phyla of all animals All have jointed legs, exoskeleton, segmented body

Crustaceans Shed their exoskeleton (molting) Live in water and have gills Can regenerate some parts

Centipedes and Millipedes Centipedes have one pair of legs in a segment and are carnivores Millipedes have two sets of legs in a segment and are herbivores

Arachnids Bodies are divided into two main sections: A head-chest section and an abdominal section All have 8 legs Only arthropod w/o antennae

Insects Body is divided into three main sections: head, thorax (chest), and abdomen Has three pairs of legs, antennae, and most have wings

Insects Open circulatory system Shed their exoskeleton as they grow

Insects Metamorphosis stage changes (egg to larva to pupa to adult) Pheromones – powerful chemicals released to attract a mate

Phylum Mollusca Mollusks All have soft bodies All have a mantle to produce shell

Univalves/Gastropods (one-shelled) Live in ocean, freshwater, or on land (need moisture) Radula files off bits of plants

Univalves/Gastropods (one-shelled) Some inject poison, dangerous to people Moves along mucus

Bivalves (two-shelled) Move by clapping the two shells together

Bivalves (two-shelled) Bivalves are often called filter feeders because they spend most of their time straining water for food

Tentacled/Cephlopods Have some part of a shell within their body (except nautilus)

Tentacled/Cephalopods Number of tentacles for capturing food varies Water jet propulsion for movement

Phylum Echinodermata Echinoderms Name means “Spiny-skinned” Regenerate lost/broken body parts

Phylum Echinodermata Echinoderms Water vascular system five-part radial symmetry

You are done with the notes. Now you have everything you NEED to be ready for next week’s test. There is no excuse to do poorly - you have a week to prepare and memorize these facts!