To determine how long a fish can be kept out of the water, hold your breath when you take your fish out of the tank. When you need to breathe, then so does your fish. Sight and sound Many fish have an excellent sense of sight and fish see colors. They also have ears, however, they don't have external openings. The ears pick up vibrations and help the fish hear and navigate.
Fish also have a unique navigational aid unlike anything found on mammals.
The structure is called the lateral line and runs along the side of the fish. The lateral line contains small sensory hairs that can detect even tiny vibrations. This extra organ allows fish to navigate and hunt prey even in low light or cloudy water conditions. Summary Fish have many unique adaptations that help them to flourish in their watery world. By better understanding their basic differences in anatomy and physiology we can better appreciate and care for these unique creatures.