Experimental manipulation of male eggspots demonstrates female preference for one large spot in Pseudotropheus lombardoi

Abstract

Females of the Lake Malawi cichlid Pseudotropheus lombardoi preferred males with one eggspot, the natural number, on their anal fin compared to males with two eggspots which had been artificially manipulated in number. Furthermore by manipulating the size of the eggspot, it was found that females preferred males with one large eggspot to males with one small eggspot. These results indicate that female preferences are responsible for the single eggspot in P. lombardoi and that this may be linked to species recognition as females of closely related species appear to exhibit different preferences for male eggspots. 2002 The Fisheries Society of the British Isles

Heritability and adaptive significance of the number of egg-dummies in the cichlid fish Astatotilapia burtoni

“…Specifically, the large range of egg-spot number in A. burtoni, and some other species [14], means that there is likely to be considerable overlap in the number of egg-spots among many species, albeit males of some species always have a lower and more consistent egg-spot number [5,7,12]. Our results may therefore call for re-evaluation of eggspots as a species recognition cue, although we also note that it is still possible that the arrangement or appearance (such as size) of egg-spots is more species-specific than their number [5,7,8].…”

“…However, neither hypothesis has been rigorously tested in cichlid fishes. Moreover, females do not necessarily prefer egg-spots that are of the same size as the ova they produce [8,12].…”

Colour variation in cichlid fish: Developmental mechanisms, selective pressures and evolutionary consequences

“…In some species, eggspot characteristics may be subject to sexual selection by female choice (e.g. A. elegans [175]; Pseudotropheus aurora [177]; P. lombardi [178]), but in other species this is not the case ( A. burtoni [176,179]). Interestingly, female Pseudocrenilabrus multicolor prefer males with spots, even though their own males don’t have them, possibly indicating an ancestral sensory bias [180].…”

Photopigment spectral absorbance of Lake Malaŵi cichlids

“…Two of the more notable theories generated to explain this astounding radiation are ecological speciation related to feeding mode and sexual selection through female choice (Danley & Kocher, 2001). Given the reliance of these theories on visually guided behaviours and that the cichlids of Lake Malaŵi exhibit both visually guided foraging and mate selection behaviour (Hert, 1991; McKaye et al , 1993; Kellogg, 1997; Couldridge, 2002; Jordan et al , 2003, 2004), a comparative understanding of visual physiology is necessary.…”