Habitat selection an male mating success in a colonial fish

Colonial breeding is prevalent in the animal kingdom yet the phenomenon is not well understood. The goal of this project is to identify mechanisms that produce breeding aggregations of sheepshead minnows Cyprinodon variegatus, a small freshwater fish in which males often form breeding colonies that females visit for matings. We will apply models that have been developed to explain leks - in which males aggregate in display territories and do not provide parental care - to colonial fishes in which males defend breeding territories and do provide parental care. Our first set of experiments will determine whether any of three models of lek formation can contribute to colony formation and distinguish between the relative power of the models to generate aggregations of male breeding territories. We will then observe the creation of colonies under controlled conditions to determine whether the behavior performed by individuals in our first experiments are replicated when males are permitted to settle in aquariums large enough to resemble natural conditions. These experiments will culminate in the use of microsatellite markers to measure actual male fertilization success in relation to the parameters predicted by the lek models. These experiments will set the stage for future studies that integrate sexual selection with classical costs and benefits of high density breeding. If we can demonstrate that sexual selection affects habitat selection by parentally caring males our results may have broad ramifications for the habitat requirements of territorial animals.

Colonial breeding is prevalent in the animal kingdom yet the phenomenon is not well understood. The goal of this project is to identify mechanisms that produce breeding aggregations of sheepshead minnows Cyprinodon variegatus, a small freshwater fish in which males often form breeding colonies that females visit for matings. We will apply models that have been developed to explain leks - in which males aggregate in display territories and do not provide parental care - to colonial fishes in which males defend breeding territories and do provide parental care. Our first set of experiments will determine whether any of three models of lek formation can contribute to colony formation and distinguish between the relative power of the models to generate aggregations of male breeding territories. We will then observe the creation of colonies under controlled conditions to determine whether the behavior performed by individuals in our first experiments are replicated when males are permitted to settle in aquariums large enough to resemble natural conditions. These experiments will culminate in the use of microsatellite markers to measure actual male fertilization success in relation to the parameters predicted by the lek models. These experiments will set the stage for future studies that integrate sexual selection with classical costs and benefits of high density breeding. If we can demonstrate that sexual selection affects habitat selection by parentally caring males our results may have broad ramifications for the habitat requirements of territorial animals.