Eucyclops macruroides has a furca which is about 8–10 times as long as wide and where the outer margins of each branch have a row of strong teeth. It is considered as very acid sensitive and is mainly distributed in the southeastern part of Norway.

Key characteristics

Eucyclops macruroides has a body which is quite slender and with a long furca which is about 8–10 times as long as wide. The outer margins of each branch of the furca have a row of strong teeth. The proximal parts of the last segments of the first antennae have more than 20 small teeth. E. macruroides has a light yellowish grey colour.

Female: Length 1.2–1.5 mm

Male: Length 0.7–0.9 mm

Ecology and distribution

Among the Eucyclops species, E. macruroides is quite rare, occurring in less than 4 % of the localities. It is mainly distributed in three areas; the southwestern lowland, the southeastern and the northernmost parts of Norway. The species is most common in water bodies situated below 300 m a.s.l., though it is recorded at 900 m a.s.l. E. macruroides inhabits the vegetation both in small pools and in the littoral zone of larger lakes. Except for two records, it is only found in water bodies with pH>6.0. E. macruroides occurs in waters with conductivity ranging from 1.9 to 53 mS/m.

Look alikes

Eucyclops denticulatus