Gammarus duebenii Liljeborg, 1852

12. Gammarus duebenii Liljeborg, 1852

Synonyms: Rivulogammarus duebenii auct. (NB. The specific epithet is often written duebeni , and the author’s name Lilljeborg; both are incorrect.).

Description and illustrations: Sars 1890 -95, p. 507, pl. 177-1; Kinne 1954, p. 419, figs 1-4pp; Lincoln 1979, pp 243, 245, figs 111e, 112.

Ecology and habitat: Gammarus duebenii is a very euryoecious species, and generally one can say that it occurs everywhere where other Gammarus and Marinogammarus species do not thrive (see e.g. Forsman 1951, Kinne 1953, den Hartog 1964). In Norway the main biotope is supralittoral rockpools, the mouth of small and medium large streamlets (here they can ascend quite a bit upstream and live at least temporarily in pure freshwater), and intertidally, under stones and among algae in meso- and oligohaline brackish waters, as in the inner part of fjords ( Brattegard 1966, Vader 1977a).

Gammarus duebenii has also several times been found in ‘freshwater’ lakes and pools in Norway (see Økland 1970, Kjaerstad et al. 2016). As ‘marflo’ samples are often transported by fishermen between lakes and even from the shore to lakes, some of these occurrences may be not quite natural.

Distribution. Common along the whole coast of Norway, but absent from Svalbard waters. A few freshwater occurrences.