Vegetation and predators mediate color pattern frequencies in Poecilia sphenops Valenciennes
Journal Title: Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society - Year 2008, Vol 1, Issue 1
Abstract
The purpose of the present study was to investigate the body color evolution in Poecilia sphenops under different environmental conditions (aquaria vs. Peţea Lake and Băile Felix spring) and to explain what is the destiny of a non-natural color pattern when the domesticated population is moved in the wild. We concluded color patterns evolve step by step from the ornamental full-black to the ancestral phenotype, in aquaria. Although the black phenotype is one generally limited to some domesticated strains, we found it highly and natural conserved in the wild. Our observations revealed a lot of vegetation in both Peţea Lake and Băile Felix spring, where floating leaves created a darkness underwater. The darker is the water in the lakes, the higher is the chance of a black fish to escape from predators. According to ”natural selection theory”, the black phenotypes of Poecilia sphenops could be conserved in the population, or even natural produced there. When predators preferentially prey on the less pigmented individuals, the black ones (both males and females) have an increased fitness. Consequently, according to ”sexual selection theory” darker females with a preference for darker males will have a higher fitness than darker females which have no such a preference. Black males have an advantage to inseminate more females and produce more black progeny. In this way, the cumulative effect of natural and sexual selection maintain the mutant and fancy black phenotypes in the feral molly populations.
Authors and Affiliations
Valentin Petrescu-Mag, Radu Lozinsky, László Csép, Ruxandra Petrescu-Mag
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