Bryocamptus rhaeticus is not found in Svalbard Archipelago and in Southern Norway, elsewhere it has a scattered distribution.
Bryocamptus rhaeticus is a morphologically variable species having a rather slender body. The exopod in the first four legs has three segments, while the endopod is 2-segmented. In the first leg, the endopod has the same length as the exopod, but for the legs 2–4, the endopod is considerably shorter than the exopod. Its rostrum is small, while the operculum has 5–10 long, sharp spines. The caudal ramus is longer than wide, the inner margin with a group of long spines. The antennule consists of eight segments. The egg sac has two eggs.
Female: Length 0.47 mm
Male: Length 0.27–0.38 mm
Ecology and distribution
Bryocamptus rhaeticus, which has a Palearctic distribution, lives in the littoral zone of small and middle sized waterbodies, in wells, springs, brooks, mosses and groundwater. It is recently found in Norway, and so far 63 % of the records are from lakes, while 23 % are from ponds. Bryocamptus rhaeticus, which is a cold stenotherm species, is widespread in Europe. It is known as a character species for mountain areas of Central Europe, though it is not found on the highest peaks. However, it may also be found in shallow, warm pools.