Life cycles and distribution of the aquatic gastropod molluscs Bithynia tentaculata (L.), Gyraulus albus (Muller), Planorbis planorbis (L.) and Lymnaea peregra (Muller) in relation to water chemistry

Abstract

The ecology of the aquatic gastropods Bithynia tentaculata, Gyraulus albus, Planorbis planorbis and Lymnaea peregra in North West England was investigated over 13 months at sites chosen for their wide range of water chemistry . Multiple regression analysis was used to determine the significance to the mollusc distributions of a variety of physico-chemical factors . Biotic factors were not considered . The species had similar life cycles, with little difference between populations within a species . B. tentaculata could live for over a year, and the major water chemistry variable was potassium (+), where the sign is that of the regression coefficient . G. albus could also survive into a second year and the major variable was mud substratum type (+). Rock substratum type (-) was the most important factor for P. planorbis. There was a slight difference in the life cycles of L. peregra in hard and medium compared with soft waters and the major water chemistry variable was magnesium (-) .

Benthic macroinvertebrates in Italian rice fields

“…Five families and 6 species of Gastropoda were detected. Among them, the species Bithynia tentaculata (Linnaeus, 1758), Gyraulus albus (Müller, 1774) and Planorbis planorbis (Linnaeus, 1758), considered good indicators of water quality (Dussart, 1979), were very common and widespread. Valvata piscinalis (Müller, 1774) is a relatively tolerant organism, and generally lives in slow or steady waters, mildly polluted (Kalyoncu et al, 2008).…”

Life cycle of Lymnaea peregra (Gastropoda: Pulmonata) in the Leicester canal, U.K., with an estimate of annual production

“…The mean water temperatures recorded at these sites were 14.89, 15.15 and 15.90 "C respectively, suggesting that at warmer sites there is a greater chance of a second brood being produced. The effect of water hardness on growth patterns and distribution has been reported (Dussart, 1979) where hard and medium hard waters (> 30 mg 1-' CaC03 alkalinity) held L. peregra populations showing overlap of generations with eggs laid in early spring and summer. In soft waters the snails were much smaller with little overlap of generations.…”

Mollusc communities of lowland rivers and oxbow lakes in agricultural areas with anthropogenically elevated nutrient concentration

“…He recorded a late summer peak, especially in August, in the density and the number of mollusc species, followed by a decrease in autumn. Dussart (1979), ØKLand (1983, BendeLL & mcnIcoL (1993), Hornbach & DeneKa (1996) also carried out surveys on molluscs in relation to environmental factors in summer (June-September).…”