Food resource partitioning between juvenile and mature weatherfish .

This study represents a description of the diet composition of one of the largest European cobitids, the weatherfish . Specimens were collected in a drainage canal, representing a typical habitat for weatherfish, and with gut content analysis conducted with regard to individual total length and maturity stage. Overall, the weatherfish diet mainly consisted of Copepoda, Cladocera, Ostracoda, Oligochaeta, s, Chironomidae and Coleoptera larvae, Gastropoda, and detritus.

The role of detritivory as a feeding tactic in a harsh environment - a case study of weatherfish (Misgurnus fossilis).

The weatherfish (Misgurnus fossilis) is a species that is tolerant of unfavourable environmental conditions and can survive low dissolved oxygen concentrations and high water temperatures. Although this species occurs across almost the whole of Europe, and is protected in many countries, relatively little is known regarding its ecology. To determine the diet of weatherfish, 120 individuals from an artificial drainage canal in central Poland were collected in two seasons (spring and late summer) with contrasting abiotic condition (oxygen concentration, water temperature and transparency).

Environmental Variables Influencing Chironomid Assemblages (Diptera: Chironomidae) in Lowland Rivers of Central Poland.

Chironomids (Diptera: Chironomidae) are a family of dipterans with a global distribution. Owing to their great functional diversity and ability to adapt to a wide range of environmental conditions, they often dominate in freshwater macroinvertebrate communities, playing a key role in the cycling of organic matter and the flow of energy in aquatic ecosystems. Our aim was to analyze the structure of chironomid assemblages and identify the environmental factors, including current velocity, river width, water depth, water temperature, dissolved oxygen, percentage of substrate covered by vascular plants, inorganic bottom substrate, and quantity of benthic (BPOM) and transported (TPOM) particulate organic matter, that underpin variation in species richness across a set of lowland rivers in central Poland, differing by stream order and abiotic parameters.

Ephemera danica (Ephemeroptera: Ephemeridae) As a Resource for Two Commensals: Ciliated Protozoans (Sessilida) and Chironomids (Diptera).

The distribution and coexistence of two unrelated commensals, the chironomid Epoicocladius ephemerae (Kieffer 1924) and ciliate Carchesium polypinum L. 1758, on one host species, Ephemera danica Muller 1764, sampled in two small lowland rivers in 2009, 2010 and 2011, were investigated. We analyzed 288 mayfly specimens from the Bzura River and 101 from the Mroga River.

Coexistence of fish species in a large lowland river: food niche partitioning between small-sized percids, cyprinids and sticklebacks in submersed macrophytes.

In the spring and summer of each year, large patches of submersed aquatic macrophytes overgrow the bottom of the alluvial Warta River downstream of a large dam reservoir owing to water management practices. Environmental variables, macroinvertebrates (zoobenthos and epiphytic fauna, zooplankton) and fish abundance and biomass were assessed at this biologically productive habitat to learn intraseasonal dynamics of food types, and their occurrence in the gut contents of small-sized roach, dace, perch, ruffe and three-spined stickleback. Gut fullness coefficient, niche breadth and niche overlap indicated how the fishes coexist in the macrophytes.

Bioaccumulation of phenol, guaiacol and some chlorophenols by selected freshwater species of leeches.

In the recent study, the bioaccumulation ability of phenolic substances was determined with field-collected specimens of three leech species, i.e., Erpobdella octoculata (Linnaeus), Theromyzon tessulatum (O.

Microhabitat preferences of spined loach, Cobitis sp. in the Grabia River--multivariation approach.

The pattern of microhabitat preferences of spined loach was examined in a natural, unpolluted lowland river. This fish co-occurred with 9 other species but non-random association was noted only with Ukrainian Lamprey, the most abundant species in the studied fish community. Spined loach was distributed only in areas adjacent to river banks.