Sperm competition selects for increased testes mass in Australian frogs

摘要: Game theory predicts that investment in spermatogenesis will increase with the risk and intensity of sperm competition. Widespread support for this prediction has come from comparative studies internal fertilizing species reporting positive associations between testes mass probability females mate more than one male. Data external fertilizers have generated conflicting results. We investigated how competition affects size two families Australian frogs: Myobatrachidae Hylidae. also examined effects clutch size, egg oviposition location as alternative factors might influence production. Species were ranked according to group spawning, hence Controlling body phylogenetic relationships, we demonstrated within Myobatrachidae, explained a significant amount variation mass. Oviposition had weak influence, ovipositing into foam having smaller testes. No or detected. In hylids, relationship was but not significant, again no predictable related number. These data provide an important test externally taxa.