Male eastern mosquitofish (Gambusia holbrooki) do not court females. Instead they display coercive mating in which females are harassed and forcibly fertilised using a colourful external male organ called the gonopodium. Buechel et al (Proc. R. Soc. B (2016) 283: 20161796) artificially selected strains of fish with extremely long (L) or short (S) gonopodia and found that female, but not male, brain size increased in the type (L) strain. How might selection pressures on males differ between coercive and non-coercive mating systems? In their natural habitat male mosquitofish with slightly longer gonopodia show higher fitness than those with shorter gonopodia. But, when reintroduced into the wild (L) males showed lower fitness than the native males. Hypothesise why this might be and describe how this could be tested. Brain development is a costly trait. Formulate a hypothesis for the difference in brain development between type (L) male and female mosquitofish.In the wild, large brained mosquitofish live longer than those with small brains but Kotrschal et al (Biol.Lett. (2019) 15: 20190137) measured survival under protected conditions and found that both male and female fish with large-brains are much shorter lived than their small-brained counterparts. Why might this be?
NEED A PERFECT PAPER? PLACE YOUR FIRST ORDER AND SAVE 15% USING COUPON:
