DO THE COLORS OF PARENTS, COMPANIONS AND SELF INFLUENCE ASSORTATIVE MATING IN THE POLYCHROMATIC MIDAS CICHLID

Most of the polychromatic Midas cichlids, Cichlasoma citrinellum, in Nicaragua are normally coloured (normal) but about 8% lack melanophores and are thus gold coloured (gold). Previous work in the field and laboratory has shown that when fish are free to interact they mate assortatively by colour; how this is achieved is unknown. Female choice of mate by colour when only visual information is available could result from previous experience with colour of parents, companions or self. Alternatively, choice could reflect an inherent bias: females might select normal males because they bear the 'primitive' colour pattern, or females that have genes for a particular colour morph might choose males of that colour. The females fell into nine different groups according to colour of their parents, companions (siblings, after parental care had ceased) and their own colour. Females visited males of either colour morph, normal or gold, viewing them through one-way mirrors. Females responded significantly more to normal males than to gold ones, but not consistently so; we argue that this bias was due to the 'primitive' colour effect. Colour of parents and of companions had weaker but neverthless significant effects on female responses whereas the female's own colour did not. Assortative matings may result from an indirect effect of gold on aggressiveness. © 1990 The Association for the Study of Animal Behaviour.