Chapter 4

Invertebrate Animal

Invertebrate animals are animals that do not have a backbone (or any bone tissue)

Invertebrate Animal

Invertebrates live just about anywhere- frozen tundra- tropical rain forest- desert- water

Invertebrate Animal

The fact that invertebrates do not have a backbone seems to limit their size

Ocean dwelling invertebrates can be quite large

Sponges

• Poriferans – having many pores1) Sessile – do not move2) Made up of a collection of cells3) Feed continuously on plankton

and tiny organismsReproduces:

asexually – buds break offsexually – fertilized eggs become larva

Cnidarians

• Central body cavity1) Have tentacles2) Have nematocysts (stinging cells with a barbed

filament)3) Food enters and waste exits through same

openingReproduces: sexually – larvae

asexually -buds

Worms• 3 types of tube shaped organisms– Take in oxygen through their skin1) Flatworms – simple body structures2) Roundworms – have body systems; decomposers3) Annelids – segmented, simple organ systemsReproduce sexually and asexually; have male and female parts

Mollusks

• Soft bodied1) Many have shells2) Have a muscular foot3) Have a mantle (layer of folded skin for

protection)

Echinoderms

• Spiny skinned1) Exoskeleton2) Have skeleton-like plates3) Have tube feet

Star fish

Sand DollarSea Urchin Shell

Arthropods

• Jointed legs1) Exoskeleton that molt2) Generally has head, thorax, abdomen3) Has open circulatory system (no blood vessels)

Class: Insects

1) Have 3 pairs of legs2) Reproduce sexually3) Undergo metamorphosis

(larva pupa adult)

Video

Class: Crustaceans

1) 3 pair of legs, 2 pair of sensory antennae2) Open circulatory system3) Reproduce sexually

Class: Arachnids

1) Exoskeleton2) 4 pair of legs, no antennae3) 2 body segments

Millipedes, Centipedes

1) Long segmented bodies2) Millipedes have 2 pairs of legs per segment3) Centipedes have 1 pair of legs per segment

Body plans

• Radial symmetry– organized around a central point– mouth-like opening leads to a gut

• Bilateral symmetry– Identical left and right side– Mouth at front, waste opening at end