Fish: Hearing, Lateral Lines (Mechanisms, Role in Behavior, Adaptations to Life Underwater)

The marine environment is filled with a wide range of sounds, some resulting from natural sources such as waves, wind, and rain, some from biological sources such as invertebrates, marine mammals, and fishes. These sounds are used for communication and are involved in a wide range of behaviors. While there is no external fish ear, all fishes have an inner ear that closely resembles that of other vertebrates, including mammals. Fishes are therefore able to detect a wide range of sounds, and they are able to glean a great deal of information about their environment by listening to natural and biological sounds. Many species of fishes use sounds to communicate for finding mates, defending territories, and warning of danger. Even species that do not use sound for communication are able to detect sounds. Most fishes can detect sounds from below 50 Hz to over 800 Hz, whereas there are many fishes that have specializations in their auditory systems that extend the range of frequencies that these species can detect and improve their sensitivity. Since sound is so important to fishes, there is growing concern that human-generated sounds may interfere with the ability of fish to detect biologically relevant sounds