Jellyfish:
External respiration:
The exchange of gases between the environment and an animal occurs by diffusion through a wet surface on the animal which is permeable to oxygen and carbon dioxide. Diffusion is the random movement of molecules and causes a net movement of molecules from a region of high concentration to a region of low concentration. Thus, oxygen moves into an organism because its concentration is lower inside than in the environment (air or water); carbon dioxide moves out of an organism because its concentration is higher inside than in the environment
Direct Diffusion:
Oxygen diffuses from the environment through cells on the animal’s surface and then diffuses to individual cells inside.
In the Jellyfish, oxygen enters through the epidermis, the thin outer layer of skin, and into the mesoglea. In the mesoglea, oxygen is abosorbed by cells and is taken in to the metabolic area of the jellyfish. The mesoglea also acts as an oxygen store for when they encounter an environement with low levels of oxygen.
