English: Water mites (Hydracarina) are a very species-rich group of small arachnids, divided into more than 50 genera. There are over 6,000 species in the world, over 100 in Estonia. In Estonia, water mites mostly live in shallow stagnant waters. In other parts of the world, they are also often found in streams, springs, groundwater and the sea. They all come from land-dwelling ancestors. The life cycle consists of a parasitic larva, two pupal-like resting stages (proto- and tritonymph), a predatory deutonymph and a predatory adult. There are four pairs of true legs, the body is spherical or disk-shaped. Larvae parasitize insects, whose larvae they can easily spread to other bodies of water. This specimen was found in a city pond in the city of Rakvere in Estonia