Meeting Abstract
Fish communities are often composed of related species that vie for similar resources, thus facing competitive exclusion. In many cases, resource and niche partitioning play a role in supporting coexistence among species. These processes can be facilitated by several strategies such as trophic divergence, utilizing varying prey capture techniques, or occupying different microhabitats based on physio-chemical gradients. Fishes of the family Fundulidae provide an ideal model for studying this phenomenon as they are globally distributed and occupy diverse freshwater, brackish, and marine habitats. Fundulus grandis, F. majalis, and F. heteroclitus are among multiple killifish species found along the East Coast of the United States; specifically, these three species and related species Cyprinodon variegatus and Poecilia latipinna commonly occupy estuarine communities in Southeastern United States. Niche partitioning within killifish communities based on salinity tolerance has been thoroughly examined, but little experimentation has been completed to determine if other environmental factors play a similar role in reducing interspecific competition. Based on field observation and previous study we hypothesize that water temperature may be an important environmental factor that supports niche partitioning within these estuarine communities. Using a series of mesocosm experiments in monocultures and simulated communities, we plan to determine if killifish and related species prefer and/or specialize in occupying habitats of differing temperatures to reduce competition and facilitate niche partitioning.
