Increase in demand of fish from Lake Victoria region has created gaps in local fish supplies and this raises concern since there are reports of limited animal-source food consumption plus protein and micronutrients deficiencies in this region. To fill the gap, less-preferred pelagic fish species such as Mukene (Rastreneobola argentea) and by-products from filleting Nile perch (Lates niloticus),...

This study focused on variation in fish mercury (Hg) concentrations in 185 Nile perch (Lates niloticus) samples collected across four different habitat types in Lake Nabugabo, Uganda, a tropical lake located proximate to Lake Victoria. We quantified the stomach contents of Nile perch using the % index of relative importance, as well as, nitrogen and carbon isotopic concentrations to assess the ...

Food consumption by Eurasian perch (Perca fluviatilis L.) and ruffe (Gymnocephalus cernuus [L.]) was studied in single and mixedspecies treatments in the laboratory, where alternative food resources, chironomids and zooplankton, were offered simultaneously. The effects of structural complexity, which was represented by substrate grain size, and of feeding level on food consumption were analysed...

The monogenean gill parasites of the genus Ancyrocephalus (Creplin 1839; Ancyrocephalidae, Dactylogyridae) are monoxenous parasites of freshwater fish (Ergens 1966; Simkov a et al. 2003; Simkov a, Matejusov a & Cunningham 2006). Adult trematodes locate mainly on the gills of the host, where they produce eggs that are released into the aquatic environment. The eggs hatch into free-living, ciliat...

With rising public concern for animal welfare, many major food chains and restaurants are changing their policies, strictly buying their eggs from non-cage producers. However, with the additional space in these cage-free systems to perform natural behaviours and movements comes the risk of injury. We evaluated the ability to maintain balance in adult laying hens with health problems (footpad de...

Detection of density dependence in animal populations is a primary goal of population ecology, and the processes causing density dependence play a major role in population regulation. Predation can strongly regulate populations by populational and behavioral responses of predators to their prey. Here I evaluate the existence and strength of density-dependent mortality in local populations of a ...

Two Daphnia species exhibited similar dynamic patterns in western Lake Erie. Populations peaked in early summer, declined to minimum abundance in mid-July, and then disappeared after August. To determine relative importance of food limitation and young-of-year (YOY) fish predation in regulating Daphnia dynamics, we examined relationships (I) between edible phytoplankton abundances and Daphnia f...

Two selection methods, 1-stage selection (OSS) and 2-stage selection (TSS), for improving efficiency and profitability of selective breeding of yellow perch were evaluated, through examining the genetic and phenotypic parameters for BW of F(1) fish using microsatellite parentage assignment in this study. Approximately 94% of the sampled yellow perch progeny were assigned to single parental pair...

Several hypotheses concerning the dominance of percids under mesotrophic lake conditions were tested in five lakes of intermediate trophic state, situated in northeastern Germany. In contrast to prediction, the fish communities in four lakes were dominated by cyprinids (roach, Rutilus rutilus and bream, Abramis brama), while percids (Eurasian perch, Percafluviatilis) dominated in one lake only....

this study was conducted in order to investigate genetic diversity and population structure of pike-perch in the northern part of iran. for this purpose, 207 adult pike-perches from four regions of the caspian sea watershed (talesh coasts, anzali wetland, chaboksar coasts and aras dam) were collected. dna was extracted and by using 15 pairs of microsatellite primers, polymerase chain reaction (...