One-spotted Waterlouse

One-spotted Waterlouse - Proasellus meridianus

Alternative names
Asellus meridianus
One-spotted Water-slater
Description

This species can usually by distinguished from Asellus aquaticus by the continuous pale band along the posterior margin of the head.  However, care is needed since the two species are frequently confused. The shape of the male first pereopod is diagnostic.

Similar Species

Asellus aquaticus is very similar but this species has two pale spots on its head, rather than the single bar of Proasellus meridianus.

Identification difficulty
ID checklist (your specimen should have all of these features)
  • single pale bar on the top of the head
Recording advice

Attach an image showing the pale bar on the head or add a comment describing how you identified the 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

Widespread and fairly frequent in Britain.

VC55 Status

Status in Leicestershire and Rutland not known.

Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2025+ | 2020-2024 | pre-2020

UK Map

Additional images

No additional images available for this species.

All NatureSpot records