Differences in male coloration are predicted by divergent sexual selection between populations of a cichlid fish

Abstract

Female mating preferences can influence both intraspecific sexual selection and interspecific reproductive isolation, and have therefore been proposed to play a central role in speciation. Here, we investigate experimentally in the African cichlid fish Pundamilia nyererei if differences in male coloration between three para-allopatric populations (i.e. island populations with gene flow) of P. nyererei are predicted by differences in sexual selection by female mate choice between populations. Second, we investigate if female mating preferences are based on the same components of male coloration and go in the same direction when females choose among males of their own population, their own and other conspecific populations and a closely related para-allopatric sister-species, P. igneopinnis. Mate-choice experiments revealed that females of the three populations mated species-assortatively, that populations varied in their extent of population-assortative mating and that females chose among males of their own population based on different male colours. Females of different populations exerted directional intrapopulation sexual selection on different male colours, and these differences corresponded in two of the populations to the observed differences in male coloration between the populations. Our results suggest that differences in male coloration between populations of P. nyererei can be explained by divergent sexual selection and that population-assortative mating may directly result from intrapopulation sexual selection.

Demographic modelling with whole‐genome data reveals parallel origin of similarPundamiliacichlid species after hybridization

“…; Seehausen ; Selz et al . ) that they represent distinct species in sympatry at each island that largely mate assortatively. Some of the individuals from Python and Kissenda Islands that are phenotypically intermediate are also genetically intermediate, but others are genetically indistinguishable from P. nyererei or from P. pundamilia individuals.…”

“…; Selz et al . ). In contrast, the more shallow breeding P. pundamilia has blue male nuptial coloration (Seehausen ), visual sensitivity that is more shifted towards blue light (Maan et al .…”

Does eutrophication-driven evolution change aquatic ecosystems?

“…Male coloration is an important component of intraspecific sexual selection (i.e. female mate choice) [31,32], as well as interspecific reproductive isolation among Lake Victoria cichlids [9,32,33], and the altered light environment impeded species-assortative mate choice [9,33]. Eutrophication-induced turbidity, therefore, reduced the intensity of sexual selection within species and removed the mechanism of reproductive isolation among species [9,34].…”

Multiple strong postmating and intrinsic postzygotic reproductive barriers isolate florally diverse species of Jaltomata (Solanaceae)

“…Numerous traits and underlying mechanisms can contribute to reproductive barriers (Coyne and Orr 2004; Baack et al 2015). However, studies often focus on phenotypic traits that differ markedly between closely related taxa, and that could contribute to premating reproductive barriers between these lineages (Maan and Seehausen 2011), including aspects of mating and courtship displays (Masta and Maddison 2002; Shaw et al 2007; Selz et al 2016), and floral traits relating to pollinator discrimination between plant species (Kay and Sargent 2009). These traits also often mediate reproductive success within species (Higashi et al 1999; Coyne and Orr 2004; Ritchie 2007; Yukilevich et al 2016), and can be subject to divergent natural or sexual selection that accelerates their differentiation between lineages.…”

“…Species differences in elaborated mating traits have frequently been associated with premating reproductive barriers (Coyne and Orr 2004; Lowry et al 2008; Baack et al 2015), including behavioral isolation in diverse animal groups such as birds (Seddon et al 2013), fish (Mendelson 2003; Selz et al 2016), and especially insects (Mullen and Shaw 2014; Merrill et al 2015), as well as pollinator isolation in plants (specifically angiosperms). Divergent floral traits can produce strong pollinator isolation via differential attraction or efficiency, and available data support a key direct role for pollinators in reducing gene flow between lineages via premating effects (e.g.…”