Moina brachiata tolerates high loads of nitrogen. Since G.O. Sars found it first time in Oslo in 1860, it has only been recorded from two constructed wetland ponds in Trøgstad, east of Oslo.

Key characteristics

The head in Moina brachiata is comparatively large constituting about one fourth of its body. The eye is large and situated in the dorsal part of the head in front of the antenna which is long and quite robust. Its carapace has a square look being about as long as it is wide. The postabdomen, which is broad at the base but tapers strongly towards the end, is almost hidden by the carapace. At the base of the abdominal claw there are 5–8 strong teeth. It is almost hyaline with a tinge of violet.

Female: Length 1.0–1.6 mm

Male: Length 0.8–1.1 mm

Ecology and distribution

G. O. Sars found M. brachiata in high numbers in a pond in Oslo in the summer of 1860. According to Sars, the water was very dirty. The next year when he should retrieve some more specimens for closer inspection, he was not able to find a single specimen and the pond was densely populated by D. pulex. The next time the species was found was in two newly constructed wetland ponds east of Oslo in 2000, where it also occurred in quite high numbers. It was still found the following year. This pond was characterized by high loads of nitrogen.


Moina macrocopa