Sounds: Fish produce sounds through their swim bladders, fins, pectoral muscles, and some even vocal cords. Different sounds may convey different messages such as danger, mating calls, or territorial claims.
Body language: Fish use body movements and postures to communicate with each other. For instance, raising fins, flaring gills, and aggressive body postures may indicate a threat or warning. Tail-wagging in some species can signal contentment or a sign of submission.
Color changes: Some fish have the remarkable ability to rapidly change their body colors and patterns. These changes can indicate aggression, courtship, warning signals, or camouflage.
Scent: Fish have a developed sense of smell and may communicate through chemical signals released into the water. These chemical cues can be important in territorial behaviors, mating, and food detection.
Electrical signals: Certain species of fish (like the electric eel) generate electrical fields and use them as a means of communication and sensing their surroundings.
Vibrations: Fish can sense and respond to vibrations created in the water. These vibrations may be generated by moving predators or prey and are an essential part of their underwater communication.