High prevalences of gonadal intersex have been observed in wild fish populations in areas affected by domestic and industrial effluents. For this study, fish were collected in 1998 from the Cootes Paradise region of Hamilton Harbour in western Lake Ontario, Canada, to determine whether gonadal abnormalities, including intersex, were present in young of the year (YOY) fish. No gonadal abnormalit...

White Perch Morone americana have been introduced into many inland systems throughout the United States. To determine factors affecting White Perch abundance and size structure, we compared White Perch growth, timing of maturity, and trophic level; the abundance of a predator (Largemouth Bass Micropterus salmoides); the abundance of an ecologically significant mid-level omnivore (Gizzard Shad D...

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),...

Eleven wader species are included in the first version of the Red Data Book of the Moscow region. One of these species Jack Snipe Lymnocryptes minimus ceased breeding at the end of the 19th or beginning of the 20th century; three species, i.e. Oystercatcher Haematopus ostralegus, Wood Sandpiper Tringa glareola nd Greenshank T. nebularia breed in the Moscow region irregularl)5 as the region lies...

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 ...

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...