1. - Annelid Worms - Insects
Notes: Invertebrates
- Annelid Worms
- Insects

2. Invertebrates Animals that lack a backbone
We are going to focus on the Annelids and Insects (a class of Arthropods)

3. Annelids
Segmented Worms – each segment is a septa, have head & body segments
Closed Circulatory System: Blood moves through vessels
Consists of Earthworms (oligochaeta), Leeches (hirudinea) and marine worms (polychaeta)

4. Annelids

5. Annelid Transport
Annelids have a closed circulatory system – blood moves through vessels.
Blood is pumped to head & body transporting oxygen and carbon dioxide
Have “hearts” that pump blood, really enlarged, muscular blood vessels

7. Annelid Excretion
Annelids have a complete digestive system (contains both a mouth and anus)
Food is absorbed in the intestine.
Nearly every segment in Annelids has 2 nephridia that collect waste and transports it out of the body

8. Annelid Regulation
Annelids have a nervous system that consists of nerve fibers in each segment connected by ventral nerve cords to a simple brain near the mouth
Nervous system is used to sense the environment.
Some Annelids have eyes.

10. Annelid Respiration & Nutrition
Respiration – Annelids exchange gases through their skin. This is why their skin is moist and they live in moist environments
Nutrition – Variety of feeding methods. (predators, filter feeders, decomposers) Food passes through digestive system where nutrients are absorbed.

11. Annelid Reproduction and Growth
Earthworms & Leeches are hermaphrodites (don’t self fertilize)
When 2 mate they exchange sperm. Each forms a capsule for sperm & egg which they leave behind.
Marine Annelids have separate sexes and release sperm & egg into water for fertilization