Arctodiaptomus bacillifer was descibed from individuals sampled in the Pannonian lowland. G.O. Sars described this species from a small pond in the northeast of Norway and since then there have been two more records.

Key characteristics

Arctodiaptomus bacilllifer is a moderately robust calanoid. The lateral expansions of the last thorax segment are somewhat resembling those of Acanthodiaptomus denticornis, but are less distinctly biangular. Its antennae, reaching to the middle of the genital segment, are longer compared to those of Arctodiaptomus laticeps, where they reach the base of the first abdominal segment. The colour of the female is yellowish orange, while the male is dark red. 

Female: Length 1.3–2.3 mm

Male: Length 1.2–2.1 mm

Ecology and distribution

G.O. Sars described this species from a small pond in the northeast of Norway (not shown in the map because the exact position is not known). Since then there have been two records from two lakes situated respectively 175 and 480 m a.s.l. in Nordland county. Both lakes can be characterised as relatively electrolyte poor, and with pH just below 7.0.

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