Maraenobiotus vejdovskyi is morphologically highly variable, and is a cold-stenotherm species which is rare in Norway.
Both the exopod and endopod in the first leg of Maraenobiotus vejdovskyi are 2-segmented, while the legs 2–3 has a 3-segmented exopod and a 2-segmented endopod. Its rostrum is very reduced. The operculum has 8–12 spines, while the caudal ramus is almost as long as wide. The antennule consists of eight segments.
Female: Length 0.45–0.70 mm
Male: Length 0.46–0.50 mm
Ecology and distribution
There are so far only two records from Norway, respectively one from East- and West-Norway. The species has a Palearctic distribution. It is found in mosses near springs or swamps, in small freshwater habitats, in shore vegetation, in leaf litter and in caves. It is a typical species for streams and mossy swamps in mountainous regions.