Fluctuating asymmetries and reproductive success in the peacock blenny

Abstract

In an investigation of the relationship between reproductive success and fluctuating asymmetry (FA) in the peacock blenny Salaria pavo, FA was measured in four bilaterally paired characters in successful and unsuccessful males during the breeding season. Reproductive success among successful males was assessed by calculating the number of eggs the males were defending. Absolute FA values relative to trait size were high for all characters and it is suggested that this could be a consequence of sub-optimal environmental conditions. Two of the traits presented higher absolute FA values suggesting a lower canalization during ontogeny. No difference in FA between successful and unsuccessful males was found and no relationship between FA and number of eggs among the successful males occurred for any of the measured traits. A composite index of FA, that should better reflect overall developmental competence, was also unrelated to reproductive success. These results indicate that FA is not associated with reproductive success among males of S. pavo. Successful males were larger than unsuccessful males and a strong positive correlation was detected between the body length of the parental males and the number of eggs they had in the nest, even when controlling for the internal nest area. Body size may give males a reproductive advantage by being preferred by females and by having an advantage in male-male competition for nests of higher quality.

The role of male visual and chemical cues on the activation of female courtship behaviour in the sex-role reversed peacock blenny

“…Interestingly, previous field studies have failed to find any relation between the development of the crest and male reproductive success (Oliveira et al, 1999;Gonçalves et al, 2002), although larger males have been shown to be more successful in nature (Oliveira et al, 1999;Gonçalves et al, 2002). The present results suggest that one of the traits assessed by females during sexual interactions is the head crest.…”

“…The present results suggest that one of the traits assessed by females during sexual interactions is the head crest. In nature, males spent the majority of time with their head protruding from the nest while most of their body was inside (Oliveira et al, 1999;Gonçalves et al, 2002). Thus, the traits visually available for females to assess males should be located on the head.…”

Intersexual copying by sneaker males of the peacock blenny

“…On the other hand, the choices of males may rely on independent mechanisms, as in nature larger bourgeois males receive more eggs (Oliveira et al 1999;Gonçalves et al 2002). Associating with larger males should increase the probability of a sneaker participating in spawning events.…”

Time spent close to a sexual partner as a measure of female mate preference in a sex-role-reversed population of the blenny Salaria pavo (Risso) (Pisces: Blenniidae)

“…Corroborating these results, in our experiment females preferred to associate and directed more courtship displays towards the male that had the larger crest. In the field, however, no relation between the development of the crest and the male's reproductive success has been demonstrated to date (Oliveira et al 1999;Gonçalves et al 2002a). These results suggest a female preference towards males with more developed crests, although in the field male choosiness and male-male competition for nest sites, with larger males having a higher reproductive success (Oliveira et al 1999;Gonçalves et al 2002a), probably dilutes the effect of this preference.…”