Fish

Fish live in oceans, seas and freshwater, ranging in size from less than centimeters to several meters for adults. Fish breathe oxygen dissolved in the water through gills. The main engine of the majority of fish is the caudal fin that moves the fish forward, while the dorsal fin helps maintaining balance, and the remaining fins are used to guide the fish.

There are three groups of fish, the first having circular mouth and the second having cartilage and the third having bones. The circular mouthed fish differ from the other two groups that they lack jaws. The group of cartilaginous fish has a cartilage structure rather than a skeleton such as shark and elk. The third group (bone fish) is characterized by a dense cohesive internal structure (support) of bones and usually the skin is covered by overlapping crusts that are very small or modified sheets or solid rings. The below-listed examples are found in the museum.