1. Stage 6: Internal Segmentation
Phylum: Annelida

2. A. The Segmented Worms 1. These organisms… a
A. The Segmented Worms 1. These organisms… a. have a body plan based on repeated segments. b. Have external segmentation the allows for greater internal organization and specialization. 2. Taxonomic Classes a. Polychaetes (1) sandworms, clamworms and featherdusters. (2) Live in burrows or parchment tubes they create out of mucus, protein and or CaCO2. b. Echiurans and Pogonophorans

5. B. Structure and Function
1. Designed for movement.
2. Repeated Segments
Divided by internal
partitions.
b. Each segment has its
own function.
c. Some occur only once
some are repeated.
3. Specialized Segments
Anterior modification for
cephalization.
b. Sensory structures include
cerebral gangalion and eyes.

6. 3. Connections a. Many systems need to be connected throughout the body. b. Connections are made by many systems including the nervous, circulatory and digestive.

7. C. Niche
1. Nonselective Deposit Feeders a. Ingest anything in their path. b. Digest organic material and defecate fecal casts or castings. 2. Selective Deposit Feeders a. Separate organic and inorganic mater before ingestion. b. Requires specialized feeding structures. filter feed with fans and mucus. eversible probiscus with jaws and teeth.

8. D. Showcased System: Respiratory
1. Organs specialized for exchange of gasses (O2 and CO2) include gills, lateral flaps (of skin) and the skin itself. 2. The Skin a. Mucus coat keeps the skin moist and allows for gasses to diffuse directly into the muscles. b. This works both above and below water.

9. E. Strange But True! Meet Barry the Giant Sea Worm…
“It really does look like something out of a horror movie. It's over four feet long with these bizarre-looking jaws. “