Invertebrates

Eight Major Phyla

Phylum PoriferaPoriferans/Sponges Contains many pores Grows back together if cut or

chopped up

Phylum PoriferaPoriferans/Sponges Sexual and asexual

reproduction Made of spicules

Phylum CnidariaCnidarians Hollow, central body

cavity with only one opening (cup shaped) “tube within a tube”

Nematocysts – special stinging structures around the mouth

Phylum CnidariaCnidarians Sexual and

asexual reproduction

radial symmetry

Phylum PlatyhelminthesFlatworms Flat bodies Regeneration –

grows part back digestive tract is

tube

Phylum PlatyhelminthesFlatworms

Live in ponds and streams, bottom of plants or rocks

Some live in animal or human host, others are freeliving

Phylum NematodaRoundworms

Resemble strands of spaghetti

Live on land or in water

Can be parasites

                                                                             

Phylum NematodaRoundworms

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

Phylum AnnelidaSegmented worms Ringed Body is divided into several rings

or segments – at least 100

Phylum AnnelidaSegmented 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 MolluscaMollusks 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 EchinodermataEchinoderms

Name means “Spiny-skinned”

Regenerate lost/broken body parts

Phylum EchinodermataEchinoderms 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!