25 26 The functional response describes the relationship between feeding rate and prey density, and 27 is important ecologically as it describes how the foraging behaviour of an animal changes in 28 response to food availability. The effects of habitat complexity and food item size was 29 experimentally tested here on the foraging parameters and the functional responses of the 30 freshwater fis...

formalin is a common disinfectant and therapeutic agent in fisheries-related activities. considering large variation in susceptibility of different species to formalin toxicity, it is necessary to determine its toxicity and safety margins in different species, separately. therefore, to investigate formalin acute toxicity and safety margins on caspian roach, an experiment was conducted in 1g cas...

In this study, quantitive characteristics and chemical composition of in roach (Rutilus rutilus caspicus) sperm were investigated. Sperm traits included sperm movement duration, percentage of motile spermatozoa, sperm density, spermatocrit and sperm volume. Some seminal plasma characteristics (sodium, potassium, calcium, magnesium and chloride) were investigated. In addition, some metabolites o...

Since the 1980s, Swedish lakes have in general become less acidified. Assessment of biological recovery is, however, hampered by poor pre-acidification data, confounding effects of climate change, and few lakes with annual sampling of fish and other organisms. Only three critically acidified, but non-limed, lakes had two decades of fish monitoring. The lakes had not yet recovered to pre-industr...

According to the 'good genes' hypothesis, sexual ornaments provide an indication of the 'quality' of the bearer. In roach, Rutilus rutilus, breeding tubercles (BTs) may signal resistance against the digenean parasite, Rhipidocotyle campanula. Life history theory predicts that there should be a trade-off between parasite resistance and other life history traits. In roach, this could imply a trad...