Male sexual harassment of females is common across sexually reproducing species and can result in fitness costs to females. We hypothesized that females can reduce unwanted male attention by constructing a social niche where their female associates are more sexually attractive than themselves, thus influencing the decision-making of males to their advantage. We tested this hypothesis in the Tri...

Amber M. Makowicz,a Jessie C. Tanner,a,b Eric Dumas,a Cameron D. Siler,a,c and Ingo Schluppa aDepartment of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA, bCollege of Biological Sciences, University of Minnesota, 123 Snyder Hall, 1475 Gortner Ave, Saint Paul, MN 55108, USA and cSam Noble Oklahoma Museum of Natural History, University of Oklahoma, 2401 Chautauqua, No...

Populations experiencing consistent differences in predation risk and resource availability are expected to follow divergent evolutionary trajectories. For example, live-history theory makes specific predictions for how predation should drive life-history evolution, and according to the Trexler-DeAngelis model for the evolution of matrotrophy, postfertilization maternal provisioning is most lik...

Fluctuating asymmetry is defined as random deviation from perfect bilateral symmetry in otherwise symmetrical morphological traits and originates from developmental errors during ontogeny. It is thought to reflect the inability of a genotype to buffer itself effectively against environmental perturbations, thus providing an honest phenotypic indicator of genetic quality. It has been proposed th...

Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine preda...

Cavefishes have long been used as model organisms showcasing adaptive diversification, but does adaptation to caves also facilitate the evolution of reproductive isolation from surface ancestors? We raised offspring of wild-caught surface- and cave-dwelling ecotypes of the neotropical fish Poecilia mexicana to sexual maturity in a 12-month common garden experiment. Fish were raised under one of...

In a microchromosome-carrying laboratory stock of the normally all-female Amazon molly Poecilia formosa triploid individuals were obtained, all of which spontaneously developed into males. A comparison of morphology of the external and internal insemination apparatus and the gonads, sperm ploidy and behaviour, to laboratory-bred F(1) hybrids revealed that the triploid P. formosa males, though p...

Despite the advantage of avoiding the costs of sexual reproduction, asexual vertebrates are very rare and often considered evolutionarily disadvantaged when compared to sexual species. Asexual species, however, may have advantages when colonizing (new) habitats or competing with sexual counterparts. They are also evolutionary older than expected, leaving the question whether asexual vertebrates...

The reproductive response on the fecundity of ornamental fish guppy (Poecilia reticulata) indicates that the 0.01% concentration of natrum muriaticum 30 c potency is more significant than other concentrations. It was suggested that 0.01% concentration enhance the fecundity and increase the production of guppy.

We investigated the ability to recognize the color of surfaces in fish (Poecilia reticulata), bred from birth in conditions of artificial light with constant spectral content. The capacity for color constancy significantly deteriorated when compared that to the control group. Further alteration of lighting conditions and transfer into natural daylight conditions restored the suppressed function...