Invertebrate AnimalsInvertebrate AnimalsI. The Multicellular Condition A. Adaptations to the Multicellular Condition 1. Cell specialization and division of labor

B. Tissue Layers 1. Ectoderm 2. Endoderm 3. Mesoderm

C. Body Types 1. Acoelomate 2. Pseudocoelom 3. Coelom

D. Body Symmetry 1. Asymmetrical

2. Spherical

3. Radial

4. Bilateral

D. Cephalization 1. Mass of nerve tissue located in the anterior region 2. Accompanies bilateralism

E. Cell Specialization and Division of Labor

II. Porifera A. Phylum Examples 1. Salt water sponge 2. Fresh water sponges

B. Porifera Characteristics 1. No true tissue layers 2. Asymmetry and radial symmetry 3. No body systems 4. No true tissue 5. Filter feeders 6. Sessile

7. Spicules

Spicule types Spongin

8. Reproduction in sponges -budding -gemmule formation

III. Cnidaria A. Phylum Examples 1. Hydra 2. Jellyfish 3. Portuguese man-of-war 4. Sea anemone 5. Coral

B. Body forms: 1. Polyp is sessile 2. Medusa is free living

C. Hydra 1. Tentacles 2. Gastrodermis 3. Mesoglea

4. Specialized sting cells- Cnidoblast cells with nematocyst

Cnidoblast cells containing nematocysts Nerve net of hydra

5. Nerve net

D. Jellyfish

1. Aurelia Life Cycle

Damage caused by jellyfish sting

E. Portuguese Man-of-War

Portuguese man-of-war

F. Sea Anemone

G. Coral

Great Barrier Reef

Coral Atoll

IV. Platyhelminthes A. Phylum Examples 1. Planaria 2. Fluke 3. tapeworm

B. Phylum Characteristics 1. Flatworms 2. Ectoderm, endoderm, and mesoderm 3. Bilateral symmetry 4. Cephalization 5. Acoelomate body design 6. Free living and parasitic

C. Planaria

D. Flukes

Fasciola hepatica- sheep liver fluke

Fasciola hepatica- sheep liver fluke

Taenia saginata

V. Nematoda V. Nematoda A. Characteristics 1. Ectoderm, endoderm, and mesoderm 2. Bilateral symmetry 3. Free living and parasitic 4. “Tube within a tube“ body design 5. Pseudocoelom

B. Phylum Examples 1. Ascaris

2. Trichinella

3. Hookworms

4. Pinworms

VI. Annelida A. Phylum Examples 1. Earthworm 2. Leech B. Characteristics of Annelida 1. Segmented body 2. Numerous body systems C. Earthworm

D. Leech

VII. Mollusca A. Examples 1. Mussels, clams, oysters, scallops, snails, slugs, octopi, squid

B. Clams

Clam anatomy

Slug and Snail

Squid and Octopus

VIII. Arthropoda A. Centipede B. Millipede C. Arachnida D. Crustacea F. Insecta

B. Diplopoda- Centipede

C. Chilopoda- Millipede

D. Arachnida- Spider, tick, scorpion

E. Crustacea- Crab and lobster

F. Insecta

IX. Echinodermata A. Echinoderm Examples 1. Sea star, sand dollar

Sea Urchin

Sand dollar

Sea Cucumber