EAPSI: The Role of Behaviour and Predation in Maintaining Color Variation in an Introduced Population of Midas Cichlid in Australia

Munson Amelia A, Davis CA

Investigators

Abstract

Animals can differ dramatically in terms of their appearance or behavior, even among individuals of the same species. These differences are known as polymorphisms. Color polymorphisms, in which animals of the same species come in two or more distinct colors, can have important consequences for the life history of the animal. How these differences are maintained in a population remains largely a mystery to scientists. This is because we expect natural selection will favor individuals with the trait that is best suited for current environmental conditions and pass on genes for that trait. This should lead to the maintenance of only one color morph. However, if different color morphs excel at different tasks, multiple color morphs may be maintained in a population. In partnership with Professor Bob Wong at Monash University in Australia, the PI will conduct behavioural observations on Midas cichlid, a neotropical fish, in order to understand how predator-prey dynamics may allow for the maintenance of multiple color morphs. Midas cichlids come in both black and gold color morphs. In their native range in Central America they are predominantly black. They have been introduced to a pond in Australia where they have lived for several generations in the absence of predators. The population in Australia is predominantly gold. Barramundi, a close relative of the cichlid?s major predator in its native range, have recently been introduced to the Australian ponds by a sport fishing group. My research will help to determine whether there are behavioral differences between the color morphs in response to predator exposure that will help to explain future demographic changes in the introduced population. This will provide scientists with a clear understanding of how behaviour can help to maintain multiple color morphs. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Australian Academy of Science.