Inbreeding avoidance in a poeciliid fish (Heterandria formosa)

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Ala-Honkola O, Tuominen L, Lindström K
Publisher: SPRINGER
Publication year: 2010
Journal: Behavioral Ecology and Sociobiology
Journal acronym: BEHAV ECOL SOCIOBIOL
Volume number: 64
Issue number: 9
Start page: 1403
End page: 1414
Number of pages: 12
ISSN: 0340-5443
eISSN: 1432-0762


Abstract

Polyandry is hypothesized to give females an opportunity to avoid inbreeding through postcopulatory selection mechanisms if precopulatory inbreeding avoidance is not possible, for example, because of forced matings. Here, we report a postcopulatory, prefertilization, inbreeding avoidance mechanism in the least killifish, Heterandria formosa, a species in which males can force matings. Females had 50% less sperm in their oviducts and ovarian cavities after mating with a sibling compared to a mating with a nonsibling male. Neither sex showed inbreeding avoidance in a dichotomous precopulatory mate choice test or during mating trials. Females in this species invest substantially in each offspring after fertilization (matrotrophy), whereas males invest little more than sperm. Based on theory, females should therefore be more likely than males to avoid inbreeding in this species. We suggest that females do this by reducing the amount of sibling sperm in their reproductive system. However, the possibility that males invested more sperm to nonsiblings could not be ruled out. In a fertilization success experiment, the first male to mate with a female sired all the offspring in most cases, even if it was a sibling. However, large females were more likely to carry offspring of multiple males. Possibly female sperm storage sites were filled by the first male, and only large females had space for the second male's sperm.


Keywords

Heterandria formosa, Inbreeding avoidance, Poeciliidae, Polyandry, Postcopulatory sexual selection, Precopulatory sexual selection

Last updated on 2020-24-02 at 02:57