Two-spotted Water Hog-louse - Asellus aquaticus

    Alt Name
    Two-spotted Water-slater
    Description

    This crustacean is closely related to woodlice but lives entirely in water. It is one of four waterlouse species in Britain, two of which are known to be found in Leicestershire and Rutland. Asellus aquaticus is the commonest and can be recognised by the two pale spots on the head.

    Similar Species

    Proasellus meridianus is very similar but can be differentiated by having a single bar-like spot on the back of its head.

    Identification difficulty
    ID guidance
    • two spots on the back of the head
    Recording advice

    Attach an image showing the head spots or add a comment describing how you identified this species.

    Habitat

    Often found in stagnant water as they can tolerate low oxygen levels. They do not swim well but tend to crawl around weed and mud.

    When to see it

    All year round.

    Life History

    They are detritus feeders, eating decaying organic matter. The species breeds throughout the vegetation period, most frequently in spring. Females carry eggs in brood pouches underneath their body.

    UK Status

    It is common and widespread in Britain.

    VC55 Status

    Common in Leicestershire and Rutland.

    Leicestershire & Rutland Map

    UK Map