Relictogammarus stoerensis ( Reid, 1938 )

Vader, Wim & Tandberg, Anne Helene Solberg, 2019, Gammarid amphipods (Crustacea) in Norway, with a key to the species, Fauna norvegica 39, pp. 12-25 : 21-22

17. Relictogammarus stoerensis ( Reid, 1938)

Synonyms: Gammarus stoerensis Reid, 1938 ; Marinogammarus stoerensis auct.; Chaetogammarus stoerensis auct.; Echinogammarus stoerensis auct.

Description and illustrations: Stephensen 1935 -42, p.

346. fig. 49 ( Marinogammarus st.); Sexton & Spooner 1940, p. 662, fig. 8 ( Marinogammarus st.); Lincoln 1979, p. 271, fig. 125 ( Chaetogammarus st.).

Ecology and habitat: Intertidal, under stones and in gravel, coarse mud-intermixed sand or other mixed fine substrate, at places where lesser amounts of freshwater flow out. The vertical distribution covers almost the entire intertidal, down from MHWN; higher up it is often replaced by Gammarus duebenii . R. stoerensis tolerates much brackish water; in the Sognefjord the first author ( Vader 1977a) found them at Dale in the Lusterfjord, where the fjord is ice-covered several months each winter. In the inner fjords R. stoerensis may be almost dominant some places (cf Skadsheim 1983) and it is there, where the salinity is very variable during the year, much less confined to freshwater trickles.

Distribution in Norway: Probably common along the entire Norwegian coast, but absent from Svalbard. There are as yet few records from N. Finnmark ( Vader 1971), but the species also occurs in the Murmansk region ( Segerstråle 1948).