Answer: Adaptation
Step-by-step explanation:
Adaptation of fishes to the aquatic (water) habitat requires that they have the following:
- Scales, the hardened pigment that covers the skin of fishes and some other animals.
- Gills, the organ used by most fishes to breathe under water.
Other include tail, fin (dorsal, pelvic) etc. All these help the fish to adapt to the water environment.