title: Differential allocation by female zebrafish (Danio rerio) to different-sized males--an example in a fish species lacking parental care.
abstract: Organisms allocate resources to reproduction in response to the costs and benefits of current and future reproductive opportunities. According to the differential allocation hypothesis, females allocate more resources to high-quality males. We tested whether a fish species lacking parental care (zebrafish, Danio rerio) expresses male size-dependent differential allocation in monogamous spawning trials. In addition, we tested whether reproductive allocation by females is affected by previous experience of different-quality males, potentially indicating plasticity in mate choice. To that end, females were conditioned to large, small or random-sized males (controls) for 14 days to manipulate females' expectations of the future mate quality. Females showed a clear preference for large males in terms of spawning probability and clutch size independent of the conditioning treatment. However, when females experienced variation in male size (random-sized conditioning treatment) they discriminated less against small males compared to females conditioned to large and small males. This might suggest that differential allocation and size-dependent sexual selection is of less relevance in nature than revealed in the present laboratory study.
authors.affiliation: Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany. silva.uusi-heikkila@utu.fi
authors.forename: Silva
authors.initials: S
authors.lastname: Uusi-Heikkilä
authors.forename: Linda
authors.initials: L
authors.lastname: Böckenhoff
authors.forename: Christian
authors.initials: C
authors.lastname: Wolter
authors.forename: Robert
authors.initials: R
authors.lastname: Arlinghaus
mesh_terms: D000818:Animals; D049628:Body Size / Q000502:physiology; D005260:Female; D008297:Male; D012098:Reproduction / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology; D015027:Zebrafish