Simocephalus exspinosus

Simocephalus expinosus seems to feel comfortable in small nutrient rich ditches and ponds. This is due to less competition from other species, which are more sensible to these conditions.
The carapace of Simocephalus expinosus has a shape which is very similar to that of S. vetulus, even the head which is comparatively small, and noticeably delimited from the carapace by a depression on the dorsal side. In contrast to S. vetulus the eyespot is not elongated but more or less circular. The abdominal claw in S. expinosus is easily distinguished from the two other Simocephalus species having a varying number of teeth (12–22) at the base. S. expinosus is less transparent than S. vetulus and has a yellowish brownish-oliveaceus colour.

Female: Length 1.3–4.2 mm
Male: Length 1.0–1.5 mm
Water bodies containing S. expinosus are generally small, pH is about neutral and conductivity is high ( more than 7 mS/m). All records are from localities situated below 500 m a.s.l.