Unionid bivalves
 of the pilica river catchment area

Abstract

The 1995-1998 studies on the unionid fauna of the Pilica catchment area (C Poland) included 103 localities in the river, tributaries, floodplain water bodies and the dam reservoir on the river. As a result of qualitative and quantitative sampling six unionid species (one represented by two forms) were recorded: Unio crassus Philipsson, U. tumidus Philipsson, U. pictorum (Linnaeus), Anodonta cygnea f. cygnea (Linnaeus), A. cygnea f. cellensis (Schröter), A. anatina (Linnaeus) and Pseudanodonta complanata (Rossmässler). Three of them: U. crassus, A. cygnea f. cygnea and P. complanata were found to be rare. Dominance structure and density of unionids are discussed. Spatial distribution and abundance are analysed on the background of such ecological factors as character of bottom sediments, bottom configuration, vegetation, distance from shore, seston content as well as physico-chemical, hydrobiological and bacteriological water pollution. Ecological preferences of each species are described. Selected populations are characterised with respect to their age structure. Species which were abundantly represented are characterised with respect to their metric characters and sexual dimorphism, as well as effect of zebra mussel on their growth and condition.

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

“…The species nomenclature follows GLöer & MeIer-BrooK (1998) and GLöer (2002). The age of U. crassus was estimated according to PIechocKI & DyduchFaLnIowsKa (1993) and AbraszewsKa-KowaLczyK (2002). Empty shells were excluded from the analyses.…”

“…the type of bottom and the sediment grain size, in addition to the physical and chemical parameters of the water, which affect the occurrence of unionid species in rivers, including U. crassus. According to ABraszewska-KowaLczyK (2002), U. crassus occurs both near the shores in the shallows and on a sloping bottom as well as in the current. The thick-shelled river mussel avoids organic-rich muddy substratum and is more abundant in sandy tributaries.…”

“…Moreover, individuals up to six years old with the maximum shell length of 66.9 mm were also observed there. The maximum shell length and age of specimens varied among rivers and amounted to 47.8 mm (10 years old) in the Płociczna River (Poland, Ecoregion 14), 68.0 mm (18 years old) in the Szeszupa River (Poland, Ecoregion 16), 79.1 mm (6 years old) in the Pilica River and its tributaries (Poland, Ecoregion 14), 85.0 mm (25 years old) in the Höjea River (Sweden) as well as 94.0 mm (32 years old) in the Suså River (Denmark) (ZettLer 2000, AbraszewsKa-KowaLczyK 2002.…”

“…Some authors pointed out that the main environmental factors that acccounted for most of the variability in the mollusc community structure in floodplain water bodies including oxbow lakes were the physical and chemical parameters of the water, i.e. concentration of dissolved oxygen, chlorides, nutrients, permanence of the water body, its size and depth, types of bottom sediments, insolation and hydrological connectivity or even complexity of woody debris (aBraszewska-kowaLczyk 2002, schneIder & wInemILLer 2008, Jurkiewicz-karnkowska 2009, oboLewsKI 2011a, funK et al 2013). suren et al (2008 found that gastropods and bivalves (only Sphaeriidae) were restricted to wetlands (including ponds) with a higher pH and conductivity combined with a lower nitrite-nitrogen concentration (mean concentration of up to 3.50 µg N-NO 3 dm -3 in the water).…”

Bivalves of the family Unionidae in ox-bow lakes of the Bug River

“…Widuto & Kompowski 1968, Lewandowski & Stańczykowska 1975, Kasprzak 1985, Lewandowski 1991), rivers (Piechocki 1969, Lewandowski 1990, 1996, Abraszewska-Kowalczyk 2002and others) and dam reservoirs (e.g. Krzyżanek 1976, Jurkiewicz-Karnkowska 1989, Dusoge et al 1999 are the biggest freshwater invertebrates in Poland.…”