East Carolina University : Research and Creative Achievement Week 2011
Fitness Components of Color Pattern Variation in a Female Polymorphic Stickleback Population, Kevin Shah, Department of Chemistry, East Carolina University, Greenville, NC 27858 The three-spine stickleback has now become a model system in sexual selection and evolutionary ecology. During the reproductive season, males have a characteristic red throat that is used in malemale contests and is the target of female choice. The McKinnon laboratory has discovered populations in British Columbia and California that harbor a rare color polymorphism wherein some females exhibit red throat coloration, a typically male trait. In order to explore the forces maintaining such polymorphism, we studied critical life history parameters in a wild-caught laboratory maintained population and tested whether red- and dull-throated females differ in fecundity, condition, clutch size, mean egg size and weight, growth rates, inter-clutch interval and number of clutches. We find no evidence of divergence in the traits examined and we discuss these results in the context of polymorphism maintenance and adaptation.
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The Territorialism and “Social Networks of Dusky Damselfish and Yellowtail Damselfish, Jessica Pendergrass, Department of Biology, East Carolina University, Greenville, NC 27858 Dusky damselfish (Stegastes adustus), and yellowtail damselfish (Microspathodon chrysurus) are species that are commonly seen along the coral reefs in San Blas, Panama. Feeding areas of adults of the largest damselfish species, Microspathodon chrysurus, are superimposed on feeding areas of adults and juveniles of the Stegastes adustus. The large species aggressively dominates its smaller interspecific cohabitants. Cohabitant individuals of each species eat the same types of benthic microalgae. M. chrysurus has the same daily cycle of feeding activity as S. adustus, uses the same feeding microhabitats as they do, and feeds almost exclusively in their feeding areas. Cohabitants defend their feeding areas against the same set of other herbivorous fishes, but M. chrysurus is involved in defensive actions much less frequently than is S. adustus. Thus adults of M. chrysurus appear to be dependents that use their size-based dominance ability to obtain food from their cohabitants (Robertson). The project hypothesized that both dusky damselfish and yellowtail damselfish protect the same resources from the same herbivores, and that both species have a similar “social network” make-up. The fish‟s “social network” was defined as all the species of fish observed in the direct area with the damselfish while observation was taking place. It was discovered that both dusky damselfish and yellowtail damselfish protect the same resources from the same herbivores, but that both species do not have a similar “social network” make-up.
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