Alona karelica has either a bright grey colour, or may be hyaline. The first record in Norway was made in 1978, but later it has been found many times. It is associated with neutral, electrolyte rich lakes. 

Key characteristics

This species can be confused with Alona costata but the carapace is not striated. However, A. karelica is also characterized by the blunt tip of the rostrum, and it has no lateral head pores. Denticles are increasing in size proximately with a few long and thin spinules at the edge. The basal spine of the abdominal claw is very small. It either has a bright grey colour, or may be hyaline. 

Female: Length 0.3–0.5 mm

Male: Length 0.3–0.5 mm

Ecology and distribution

The first record of A. karelica in Norway (1978) is from the central parts of south-Norway. Today it is found in 2 % of the investigated localities from all parts of the country situated between 17 and 979 m a.s.l. So far there are no records from small ditches or from the largest lakes. Otherwise, this littoral chydorid is found in water bodies of all sizes and with pH ranging from 5.7 to 8.2. The majority of records are from electrolyte rich lakes. 


Alona costata