Fish, with more than 35,000 described species, are the most diverse group of vertebrates and have inhabited the Earth’s waters for more than 500 million years. They are exceptionally adapted to life in water: most breathe through gills, use their fins to move and steer, and have streamlined bodies. From the depths of the oceans to clear mountain streams, fish have colonised almost every aquatic habitat and evolved an astonishing variety of shapes, colours and survival strategies, ranging from species only a few millimetres long to the enormous whale shark.
…that fish can perceive movements in the water without seeing it? Many fish use their lateral line system to sense even the slightest water movements and changes in pressure. This allows them to detect obstacles, prey and predators, as well as the movements of other fish – an important ability that, for example, enables perfectly coordinated swimming in schools.
