No male mate choice for female boldness in a bi-parental West African cichlid, the rainbow krib (Pelvicachromis pulcher)

Abstract

Background In many species, males have a lower reproductive investment than females and are therefore assumed to increase their fitness with a high number of matings rather than by being choosy. However, in bi-parental species, also males heavily invest into reproduction. Here, reproductive success largely depends on costly parental care; with style and amount of parental effort in several cases being associated with personality differences (i.e., consistent between-individual differences in behaviour). Nonetheless, very little is known about the effect of personality differences on (male) mate choice in bi-parental species. Methods In the present study, we tested male mate choice for the level and consistency of female boldness in the rainbow krib, Pelviachromis pulcher, a bi-parental and territorial West African cichlid. Individual boldness was assumed to indicate parental quality because it affects parental defence behaviour. For all males and females, boldness was assessed twice as the activity under simulated predation risk. Mate choice trials were conducted in two steps. First, we let a male observe two females expressing their boldness. Then, the male could choose between these two females in a standard mate choice test. Results We tested for a male preference for behavioural (dis-)similarity vs. a directional preference for boldness but our data support the absence of effects of male and/or female boldness (level and consistency) on male mating preference. Discussion Our results suggest female personality differences in boldness may not be selected for via male mate choice.