title: Size does matter: An assessment of reproductive potential in seahorses.
abstract: In most animals, the mother plays the key role in reproduction, but male pregnancy in seahorses raises the question of whether the female still is the only determinant of offspring size or if she shares some responsibility with the male. This study evaluates the effects of both male and female size on the reproductive output of the long-snouted seahorse, Hippocampus guttulatus. Results demonstrated that, with regard to reproductive potential, the bigger the better. Seahorses preferred similar-sized or larger mates. Larger females produced bigger eggs with larger yolk reserves. Larger males had larger brood pouches, but did not produced larger broods. Male size was negatively correlated with embryo density and positively correlated with juvenile size. Both parents proved to play a decisive role in the reproductive output of this species. Newborn juveniles from the same parents were 15% bigger and 30% heavier when incubated in smaller and lower-density broods. This trade-off between the number and size of embryos inside the brood pouch clearly indicates a limited carrying capacity of the male, and demonstrates that the size of newborn seahorses can be, in part, paternally determined.
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Laboratório Marítimo da Guia, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal. Electronic address: filipafaleiro@gmail.com.
authors.forename: Filipa
authors.initials: F
authors.lastname: Faleiro
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Laboratório Marítimo da Guia, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal; Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.
authors.forename: Armando J
authors.initials: AJ
authors.lastname: Almeida
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Laboratório Marítimo da Guia, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal; Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Ré
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Laboratório Marítimo da Guia, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal; Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Narciso
mesh_terms: D000818:Animals; D049628:Body Size / Q000502:physiology*; D047108:Embryonic Development; D005260:Female; D008297:Male; D012098:Reproduction / Q000502:physiology*; D023701:Smegmamorpha / Q000033:anatomy & histology* / Q000502:physiology*
keywords: Embryo density; Hippocampus guttulatus; Juvenile size; Oocyte size; Reproductive potential; Seahorse