Ceriodaphnia pulchella is common both in the zooplankton and in the littoral zone. For identification, its postabdomen is characterised by having a group of 3–5 long and thin spines in addition to the abdominal denticles. It is characterized as moderate acid sensitive.

Key characteristics

Ceriodaphnia pulchella has been mixed up with C. quadrangula. However, the shape of the postabdomen, which is smaller in C. pulchella than in C. quadrangula, can be used for identification of these species. The postabdomen in C. pulchella, which is always hidden by the carapace, has a group of 3–5 long and thin spines in addition to the abdominal denticles. The species is very transparent and almost colourless with a weak tint of yellow or green.

Female: Length 0.4–0.9 mm

Male: Length 0.4–0.7 mm

Ecology and distribution

C. pulchella is found in 8 % of the localities, and among Ceriodaphnia species, C. quadrangula is the only species that is more common. It is found both in the zooplankton and in the littoral zone. C. pulchella is mainly found in the south-eastern part of Norway. Though it is most common between 100 and 300 m a.s.l., it is also found in the alpine zone (1258 m a.s.l.). C. pulchella occurs with high frequency in ponds as well as in large lakes. Except for a few, all records are from lakes with pH>6.0. It occasionally occurs in electrolyte poor water. Highest frequency is found in lakes which have conductivity above 5.0 mS/m.

Look-alikes

Ceriodaphnia quadrangula