The swim bladder is located in the body cavity and is derived from an outpocketing of the digestive tube. It contains gas (usually oxygen) and functions as a hydrostatic, or ballast, organ, enabling the fish to maintain its depth without floating upward or sinking.
Ribosomes are small particles of RNA and protein which are found throughout the cytoplasm in all cells; they produce proteins by following coded instructions from DNA. They produce proteins through coded instructions that come from the nucleus of a cell.