Fish are aquatic vertebrate animals whose body is made up of the head, trunk and tail.
The characteristics of the fish are what have allowed them to dominate the aquatic environment:
- Its hydrodynamic shape, with a spindle-shaped body, allows it to move easily in the water.
- They have a lateral line, an organ that allows them to pick up the vibrations of the water.
- They are usually covered by scales.
- The fins allow them to make a continuous movement in the water, and can be of two types:
- Paired fins: pectoral and ventral.
- Unpaired fins: dorsal and caudal (the only one that drives it).
- The skeleton of fish can be of two types: