title: Sex-biased movement in the guppy (Poecilia reticulata).
abstract: The movement strategies of birds and mammals are often closely linked to their mating system, but few studies have examined the relationship between mating systems and movement in fishes. We examined the movement patterns of the guppy ( Poecilia reticulata) in the Arima river of Trinidad and predicted that sexual asymmetry in reproductive investment would result in male-biased movement. Since male guppies maximize their reproductive success by mating with as many different females as possible, there should be strong selection for males to move in search of mates. In agreement with our prediction, the percentage of fish that emigrated from release pools was higher for males than females (27.3% vs. 6.9%, respectively). Sex ratio was highly variable among pools and may influence a male's decision to emigrate or continue moving. We also detected a positive relationship between body length and the probability of emigration for males and a significant bias for upstream movement by males. Among the few females that did emigrate, a positive correlation was observed between body length and distance moved. Sex-biased movement appears to be related to mating systems in fishes, but the evidence is very limited. Given the implications for ecology, evolution, and conservation, future studies should explicitly address the influence of sex and mating systems on movement patterns.
authors.affiliation: School of Biology University of Leeds, Leeds, LS2 9JT, UK. darren_croft@hotmail.com
authors.forename: Darren P
authors.initials: DP
authors.lastname: Croft
authors.forename: Brett
authors.initials: B
authors.lastname: Albanese
authors.forename: Bethany J
authors.initials: BJ
authors.lastname: Arrowsmith
authors.forename: Marc
authors.initials: M
authors.lastname: Botham
authors.forename: Michael
authors.initials: M
authors.lastname: Webster
authors.forename: Jens
authors.initials: J
authors.lastname: Krause
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D011036:Poecilia / Q000502:physiology*; D012098:Reproduction; D012727:Sex Characteristics; D012726:Sexual Behavior, Animal / Q000502:physiology*; D014300:Trinidad and Tobago