Fish Dissection Practice Quiz The quiz you will be having will have the same information that is on this PowerPoint. The only difference will be the order of the slides. Filters oxygen from the water. A defense that detects pressure changes in the water. Cleans out toxic chemicals in body and secretes bile. This affects the buoyancy of the fish. Allows it to stay at the bottom or the top. Stores Bile This is where food is absorbed into the body. Propels the fish forward The fin on top of the fish used for protection and to guide it through the water.