Invertebrates

Invertebrates

Invertebrates

Make up about 97 % of all animal species

Phylum Porifera

Sponges Simplest animals Do not have tissues or organs Asymmetrical Have pores through which they filter

food andabsorb oxygen

Reproduces sexually through gametes orasexually through budding/fragmenting

Are usually hermaphrodites

Phylum Porifera

Filter feeders Sessile as adults, meaning they don’t

moveand are stuck to a surface

Phylum Porifera

Phylum Cnidarian

Includes jellyfish, corals, hydras All live in water Reproduce sexually for the

most part, but can reproduceasexually through budding

radial symmetry sting

Phylum Cnidarian

Nematocysts, coiled and uncoiled

Phylum Platyhelminthes

Flatworms Flat, thin bodies bilateral symmetry (simplest animal

withthis)

Usually hermaphrodites Reproduce sexually or

asexually through regeneration

Phylum Platyhelminthes

Ex: planarians, flukes, and tapeworms.

Most are parasites

Phylum Platyhelminthes

Phylum Nematoda

Roundworms Examples: ascaris, pinworms,

heartwormsand hookworms

Hookworms

Phylum Nematoda

Phylum Nematoda

bilateral symmetry live in wet soil or watery habitats Sexual reproduction

Phylum Annelid

segmented worms Live in moist soil, saltwater, and

freshwater Bilateral symmetry Closed circulation True digestive system reproduce sexually Examples: earthworms

and leeches

Phylum Annelid

Phylum Mollusca

Examples: snails, slugs, oysters, clams, squids, and

octopuses Most live in saltwater and freshwater but some

do live onland

bilateral symmetry have a head, body and muscular “foot” Have gills (water) or a primitive lung (land) Open circulation Sexual reproduction soft bodies that contain organs A hard outside shell protects most mollusks

Phylum Mollusca

Phylum Arthropoda

•Largest group of invertebrates•segmented bodies with jointed legs, which add flexibility•exoskeleton contains chitin, the same sugar found in fungi cell walls (and nowhere else)•must Molt which is when they shed the old exoskeleton, after the new one has grown beneath it.

Molting…

Phylum Arthropoda

Three main groups: Crustaceans Arachnids Insects More groups are out there, but….

Crustaceans

Examples: Lobsters, crabs, crayfish, rolypolys(pillbugs) Must live in water or moist areas

Most have 5 pairs of legs, but often the first pair is modified into claws

Two OR three body segments, depending onspecies

Crustaceans

Arachnids

spiders, mites, ticks, scorpions,granddaddy long legs (harvestmen)

Six pairs of jointed appendages, 4 pairs ofwhich are legs.

2 body segments—cephalothorax andabdomen

Arachnids

Insects

Live almost everywhere, except in the deep ocean

Ex.: mosquitoes, flies, ants, and beetles 6 legs 3 body segments Since insects can fly, they can escape

predators—why they are successful! (only invertebrate that canfly!) Find food Find new habitats

Insects

Metamorphosis: a series of chemicallycontrolled changes in body structure from juvenile to adult

Insects

Complete metamorphosis: the changesin the animal’s form in which earlier stagesdo not look like the adult

Four stages: egg, larva, pupa, adult Ex.: butterfly

Insects

Incomplete metamorphosis: the younginsects resemble the adults

3 stages: egg, nymph, adult A nymph hatches from the egg with the

same general appearance as the adult,only smaller

Ex.: grasshoppers, cockroaches

Insects

Many insects are pests Fleas, ticks, and mosquitoes carry

microorganisms that cause disease Grasshoppers and caterpillars

destroycrops

Insects

Many insects are the food source for otherorganisms

Other insects are useful. Ex.: make honey, wax, silk

Insects pollinate flowers that produce fruits

Phylum Echinodermata

Sea urchins, sand dollars, sea cucumbers, and seastars

Live in marine environments Name means spiny skin No body segments Radial symmetry have spines Have mouth, stomach, intestines, but no

head/brain Reproduce sexually or asexually through

regeneration

Phylum Echinodermata

Phylum Echinodermata

Phylum Echinodermata

Have an endoskeleton Have tube feet to attach firmly to

surfaces and also to move Tube feet are like suction cups