1. By Erin Corcoran and Callie Kopp

2. Three germ layers (Triploblastics) Those layers are ectoderm, mesoderm, and endoderm Most multicellular organisms have three layers

3. Bilateral

4. Coelomates Body cavity with complete lining, filled with fluid and maintains juxtaposition in order to procet organs

5. Complete digestive tract Has a mouth, esophagus, intestinal tube running through body, and an anus Leeches have a sucker around their mouths

6. Evident in annelids Concentration of sensory organs and nervous tissue by the head Helps them detect danger, locate food, and find mates

7. Segmented throughout body Segmented for movement and protection http://www.youtube.com/watch?v=dHkDdLQ 32ys

8. Hydrostatic skeleton Are found in organisms that are mainly composed of muscles and body fluids. Pressure allows the organism to change shapes and helps to produce motion. This allows them to burrow or swim. No appendages

9. Closed circulatory system Blood is pumped from the heart and stays within the blood vessels. The blood never fills up body cavities.

10. Annelids have no true respiratory organs. Gas and oxygen exchange happens through their skin Contains blood pigment hemoglobin Aquatic species have gills

11. Male/Female Reproduction Hermaphrodites Annelids have both male and female organs and can produce asexually, but it is more common for them to reproduce sexually.

12. Annelids can live in most environments. A majority live in aquatic areas They can also survive in terrestrial areas