Most fish have nearly 360 degree vision. Their eyes can work independently of one another, allowing them to see what is happening in front of them as well as behind them. The snout's location on a fish's head is comparable to the nose on a human's face. Behind the nares is a chamber lined with sensors that can detect the slightest odor.
Some fish have a sense of smell more then one million times as sensitive as a human's.
Fish sense sound waves from the water with their skin and muscles. Sound waves travel through the body hitting nerves in the ears which tell the brain when there is noise. Scientists can tell how old fish are from the otoliths, which are part of the inner ear. Gill covers protec the fragile and vital fish gills. They are composed of a few pieces of bone which very in shape and size depending on the species of fish.