ANnelida
- Phylum consisting mostly of segmented worms
- Consists of 12,000 species
- Very diverse in their head and locomotory appendages
- The three species are: earthworm, european medical leech, and the clam worm
EArthworm
Earthworms lack any kind of special respiratory organs. They breathe through a gas exchange through their skin. This occurs using areas of the body cavity known as cappilary beds. Gas exchange occurs between the capillary beds of the body surface and the environment. Oxygen is carried by the respiratory pigment hemoglobin, which is dissolved in the fluid portion of the blood.
European Medical Leech
Leeches do not have any definite respiratory organs. Therefore, they do not have a specific respiratory system, but they recieve oxygen and expel carbon dioxide in a very similar way to earthworms. It is a gas exchange through the epidermis. The capillary beds exchange gases directly through the epidermis and into the blood. Once in the bloodstream oxygen is carried throughout the body cavity by the pigment hemoglobin, which is specifically made for respiration. The hemoglobin is then transported by the blood throughout the leech.
clam worm
Clam worms have no respiratory organs. They do not have a respiratory system, however they recieve oxygen like leeches and earthworms do. The gas exchange occurs by the use of capillaries. The gas exhange occurs directly through the skin. Clam worms are unique in their placement of the capillaries though. Because they live in water and there is a current, the capillaries are located in fin-like extensions from the head of the clam worm to catch the oxygen in the current.