Abstract In many species females prefer to mate with socially dominant males, often because it elevates their fecundity by providing greater access material resources or lowers offspring mortality due superior male defence. Far fewer studies have tested whether males females. Intriguingly, an earlier study showed that when the sexes freely interact, mosquitofish ( Gambusia holbrooki ) preferent...

Male genitalia often show remarkable differences among related species in size, shape and complexity. Across poeciliid fishes, the elongated fin (gonopodium) that males use to inseminate females ranges from 18 to 53% of body length. Relative genital size therefore varies greatly among species. In contrast, there is often tight within-species allometric scaling, which suggests strong selection a...

While studies of sexual selection focus primarily on female choice and male-male competition, males should also exert mate choice in order to maximize their reproductive success. We examined male mate choice in mosquitofish, Gambusia holbrooki, with respect to female size and female dominance. We found that the number of mating attempts made by a male was predicted by the dominance rank of fema...

The perchlorate anion--an oxidizer found in rockets, missiles, some ammunition, flares, airbags, and fireworks--occurs as a contaminant in ground and surface water in many parts of the United States. Its toxic effects include inhibition of thyroid hormone synthesis. To investigate its chronic toxicity, mosquitofish (Gambusia holbrooki) adults and fry were exposed to aqueous sodium perchlorate a...

A poor start in life owing to a restricted diet can have readily detectable detrimental consequences for many adult life-history traits. However, some costs such as smaller adult body size are potentially eliminated when individuals modify their development. For example, male mosquitofish (Gambusia holbrooki) that have reduced early food intake undergo compensatory growth and delay maturation s...

Haplorchis  taichui is parasitic heterophyidae(trematoda) which lives in the intestinal mucosa of its main host and producing heterophyidosis,which is a zonootic diseases.subsequent to the authors, provious  studies which were made on parasit,s lift  cycle in nature in Khuzestan province,Iran,this experimental study was performed with the aim of establishing the parasite,s lift cycle in laborat...