Zu den Ursachen der unterschiedlichen pH‐Empfindlichkeit von Gammarus pulex L., G. fossarum KOCH (Amphipoda) und Aselus aquaticus L. (Isopoda)

Abstract

By means of ion chromatography the extensive and significantly higher loss of ions of C . pulex and C. fossarum in acid water (pH 3.0) as compared to neutral water is proved. While cations are being accumulated in the water, some ions (Na+, C1-) leave the hemolymph in important percentage, others increase highly after being set free from the cells (K+ and Ca2+). The loss of cations with Asellus aquaticus in acid water (pH 3) is clearly lower than with Gammarus, and it is not significantly higher than when the animals are put into neutral water.

Haemolymph [Na+] and [Cl-] loss in Gammarus fossarum exposed in situ to a wide range of acidic streams

“…Na + and Cl -) has been recognised to be the major response of fish to acid stress (McDonald et al 1989, Potts & McWilliams 1989, Wood 1989, Gonzales et al 1997. Similar results have been reported in crayfish (Appelberg 1985, Fjeld et al 1988, McMahon & Stuart 1989, Jensen & Malte 1990, gammarids (Rupprecht 1992) and molluscs (Pynnönen 1991). Surprisingly, and despite the numerous papers reporting detrimental effects of acidification on invertebrate communities, few studies have been performed on the ecophysiology of smaller acid-sensitive macroinvertebrate species.…”

Forest drainage: a threat to benthic biodiversity of boreal headwater streams?

“…Also, the detritivorous isopod, Asellus aquaticus, which is highly tolerant of acidification (Rupprecht, 1992), was abundant in most streams. However, according to the CCA analyses, it was not the acidity, but rather a combination of metals (aluminium and iron), moss cover and drainage intensity that contributed to the variation in species distribution and abundance.…”

Combined effects of acidification and competition on the feeding preference of a freshwater macroinvertebrate, Asellus aquaticus (Crustacea:Isopoda): a laboratory experiment

“…It has been demonstrated that crayfish among crustaceans can mobilise Ca 2+ from their exoskeleton to buffer acid effects (Wood and Rogano 1986). In acid water, cation loss was found to be significantly higher than in neutral water also in two species of the genus Gammarus, but the differences were not significant in Asellus aquaticus (Rupprecht 1992).…”