Meeting Abstract

105.1  Tuesday, Jan. 7 08:00  Community structure of fishes in a Mississippian Bay GREENFEST-ALLEN, E.*; LUND, R.; GROGAN, E. D.; Penn Center for Bioinformatics, University of Pennsylvania; Carnegie Museum; Saint Joseph’s University allenem@upenn.edu

The 323 million year old Bear Gulch Lens of the Bear Gulch Member, Heath Formation of Montana, USA preserves an Upper Mississippian marine bay in its entirety, across both its spatial and temporal spans. Here we take advantage of this preserved environment and the quality and diversity of the associated fish fauna to gain rare insight into the structure and spatio-temporal stability of Paleozoic fish communities. Potential fish communities within the bay fauna were identified as sets of taxa that tend to co-occur, or recur, across the bay transect. We introduce a network-based approach that integrates patterns of abundance and occurrence to infer potential interactions between pairs of taxa in the fauna. Recurrent groups were then identified as sets of taxa that formed coherent connected sub-networks, or modules, within this interaction network. Using this approach, we identified nine potential communities, representing a unique association of taxa linked by shared habitat preferences. All recurrent groups were present in each sampled habitat zone and the relative contribution of most to the regional fish community is consistent across the bay despite the environmental and temporal fluctuation across the habitats, suggesting a degree of temporal stability among the fish communities. Results from this analysis were integrated with an independent partitioning of the fauna into a set of functionally defined ecomorphotypes, allowing assessment of potential interactions between taxon recurrence and ecological role.