Abstracts (first author)
Innate sex recognition and learned species recognition in an invasive fish
Sex and species recognition are both fundamental to sexual reproduction. Speciation imposes modification of species recognition traits but not necessarily those for sex recognition. However, most studies either focus on sex recognition characteristics in a single species or assume sex recognition a priori and focus solely on species recognition traits. Invasive species represent an ideal opportunity to explore the relationship between these two recognition systems. I investigated interactions between the highly invasive mosquitofish, Gambusia holbrooki and the native Iberian toothcarp, Aphanius iberus. I found that male Gambusia consistently differentiated between male and female heterospecifics but initially failed to distinguish heterospecific females from those of their own species. However, they began to learn to recognise species differences within 24 hours. Given the lack of costly mating displays and nuptial gifts in the mosquitofish mating system, sex recognition and misdirected mating attempts may be less costly than species recognition. This and their rapid learning ability may be a factor explaining the invasive success of G. holbrooki.