Monospilus dispar is characterised by its carapace, which has several layers of concentric valves because the old carapace remains attached to the new one formed. It is moderate acid sensitive.

Key characteristics

Monospilus dispar seen from the side, has a more or less square form with a relatively short rostrum. The carapace has several layers of concentric valves because the old carapace remains attached to the new one formed. The post abdomen is short and thick, and evenly rounded towards the end. The abdominal claw is especially strong with a long spicule at its basis. M. dispar has only an eyespot (ocellus) and no proper eye. The carapace is slightly transparent with a strong yellow colour.

Female: Length 0.3–0.6 mm

Male: Length 0.3–0.5 mm

Ecology and distribution

M. dispar is a littoral species recorded from about 2 % of the water bodies. It has a scattered distribution and occurs from 5 to 663 m a.s.l. M. dispar is only found in localities with a surface area >1 ha and occurs with a frequency of 15 % in lakes larger than 1000 ha. It is found both in vegetation as well as on stony bottom. M. dispar is not found in the most acid localities (pH<4.5), while conductivity is varying between 1.5 mS/m and 53 mS/m.