1. The Invertebrates 

2. What is an Animal? Characteristics of animals:
Eukaryotic
Multicellular
Heterotrophic
Lack cell walls
Motile at some point during life
Two big groups: Invertebrates and vertebrates

3. Body Systems found in Animals
Digestive system – breaks down the food eaten
Respiratory system – gas exchange
Circulatory system – move gas and nutrients
Excretory system – filter blood, liquid waste
Nervous system – respond to environment
Reproductive system – make offspring

4. What is an Invertebrate???
An animal that does not have a backbone
8 major phyla and multiple smaller phyla
Includes 95% of all animals
The other 5% are vertebrates (backbone) and include the fishes, amphibians, reptiles, birds, mammals (We will come back to these later!)

5. Phylum Porifera Aka – Sponges Filter feeders
Water flows through the bodies and food particles are captured by specialized cells
Do not have a respiratory, circulation, or excretory system
Rely on diffusion for these processes
No nervous system
Rely on toxins for protection

6. Phylum Porifera Reproduction
Sexual – sperm and egg unite creating a larva that will swim to a suitable location and attach itself
Asexual
Fission – splitting in two
Budding – part of the animal breaks off and grows into a new individual

7. Phylum Cnidaria Includes anemones, jellies, and coral
Contain nematocysts
Stinging cells used for protection and paralyzing prey
Two body plans
Polyp – sessile – anemones and coral
Medusa – motile – jellies

8. Phylum Cnidaria Digestion is both extracellular and intracellular
No respiratory, circulatory, or excretory systems
Rely on diffusion
Response – nerve net that allows for the detection of stimuli
Reproduction
Sexual – sperm and egg

9. Phylum Platyhelminthes
Aka Flatworms
Can be carnivores, scavengers, or parasitic
Rely on diffusion for respiration, circulation and excretion
Response:
Head encloses ganglia (group of nerve cells)
Eyespot to detect light
Reproduction:
Most are hermaphrodites that reproduce sexually
Few are asexual and reproduce by fission

10. Phylum Nematoda Aka roundworms
Many are free-living and predatory, while others are herbivores or detritivores
Respiration, circulation, and excretion use diffusion
Response: Simple nervous system with ganglia and a few nerve cords
Reproduction: sexual, separate sexes

11. Phylum Annelida Aka Segmented worms
Feeding ranges from filter feeders to predators
Have a closed circulatory system
Blood is contained within vessels
Respiration:
Aquatic annelids have gills
Terrestrial annelids breathe through their moist skin

12. Phylum Annelida Excretion
Digestive waste exits through the anus
Nitrogenous waste is eliminated by nephridia
Response: Most have a well-developed nervous system with brain and nerve cords
Reproduction – most are sexual with separate sexes

13. Phylum Mollusca Gastropods, Bivalves, Cephalopods
Clams, oysters, mussels, octopus, squid, cuttlefish, snails, slugs
Feeding: herbivores, carnivores, filter feeders, detritivores, or parasites
Respiration:
Aquatic mollusks have gills
Terrestrial mollusks breathe through their skin

14. Phylum Mollusca Circulation
Slow moving mollusks have an open circ. system
Fast moving mollusks have a closed circ. system
Excretion: nitrogenous wastes are removed using nephridia
Response: nervous systems vary between groups from simple to complex
Reproduction: sexual be either spawning or internal fertilization

15. Phylum Arthropoda Includes crustaceans, insects, spiders
Feeding: herbivores, carnivores, or omnivores
Respiration:
Terrestrial species – tracheal tubes or book lungs
Aquatic species – gills
Circulation: open circulatory system with a well developed heart
Excretion: get rid of nitrogenous waste using Malpighian tubes or through diffusion

16. Phylum Arthropoda
Response: most have a well developed nervous system with a brain, a central nerve cord, and smaller branching nerves
Reproduction:
Terrestrial species use internal fertilization
Aquatic species use internal fertilization or spawning

17. Phylum Echinodermata
Includes sea stars, brittle stars, sea urchins, sand dollars, sea cucumbers
Water vascular system carries out essential body functions including respiration, circulation, and movement
Covered in tube feet to aid in movement and respiration

18. Phylum Echinodermata Feeding: carnivores, herbivores, filter feeders
Excretion: digestive wastes are released through the anus, while nitrogenous waste leaves by diffusion
Response: poorly developed nervous system
Nerve ring surrounding mouth and radial nerves
Reproduction: external fertilization by spawning