Geeopsis longicornis Olofsson 1917

Geeopsis longicornis (Olofsson, 1917) References and records from Norway

Tachidius longicornis n. sp. – Olofsson (1917): 34 – 35, type locality – Svalbard archipelago, several record areas given (from fresh water – Advent Bay, Esmark Glacier, Crednermorenen (moraine) and from brackish water – at Green Harbour, Billen Bay).

Tachidius longicornis Olofsson (1917) – Olofsson (1918): 183 – 646.

Olofsson (1917) considered T. longicornis to be very close to G. incisipes (Klie, 1913) – two species distinguished by their size and the morphology of the antenna. Later T. longicornis was considered to be a synonym of G. incisipes (Gurney 1932; Lang 1948). However, the species was reinstated as a valid species and placed in the genus Geeopsis by Huys (2009) as G. longicornis (Olofsson 1917) comb. nov. Olofsson (1918) found it from a brackish lagoon near Nordenskiold Glacier. The latter habitat consists of a shallow inner part with slowly running fresh water from the lowlands. Samples were taken from this part. In the lagoon ’ s outer part, water mixes with the salty water of the fjord and the proprotion of salt and fresh water changes with the tides. Another sampling locality, Lake Reliktsee (today, Vallunden), located in Crednermorenen (moraine), is connected to the sea by a channel. The tide flows in and out through the channel and therefore the water is salty (Kristensen et al. 2008). Still, Olofsson (1918) clearly indicated that he found Tachidius species in pure fresh water and suggested that this is a relict species that probably had been passively spread from northern Europe to Svalbard in later post-glacial time.