Journal Article

contribution of abiotic and biotic factors to spatial and temporal variation in population density of the least killifish, Heterandria formosa

MacRae, Pamela S. D, Travis, Joseph

2014

Overview

We report the results of a long-term examination of variation in adult density in the least killifish, Heterandria formosa, and the associations among adult density and a variety of ecological factors. We used data from 11 populations of H. formosa in Northwest Florida, collected between 2000 and 2010, to examine the relationships among temporal and spatial variation in adult density and (1) the composition of the aquatic fauna community among habitats (springs, ponds, and tidal marshes) where H. formosa are found, (2) an index of predation pressure and (3) the sampling season, distance from shore (cm), water depth (cm), and aquatic vegetation cover (%) in throw traps at each sampling event. We found clear evidence that adult densities of H. formosa vary widely but consistently among populations, with greater spatial variation than temporal variation in density estimates. Site identity explained most of the variation in density among populations, and there was no long-term consistent association of variation in density with different habitats; sites of the same habitat type were as likely to have characteristically different densities as were sites of different habitat types. Average adult densities of H. formosa increased as aquatic vegetation cover increased and as the index of predation pressure decreased, however assemblage structure was not a strong predictor of density. These results show that despite marked community, abiotic and biotic distinctions between habitat types, location-specific variation was the predominant signal in these data.

• Publisher: Springer-Verlag,Springer Netherlands,Springer,Springer Nature B.V
• Subject: adults / Agnatha. Pisces / Animal and plant ecology / Animal populations / Animal Systematics/Taxonomy/Biogeography / Animal, plant and microbial ecology / Animals / Aquatic animals / Aquatic ecosystems / Aquatic fauna / Aquatic plants / Autoecology / Biological and medical sciences / Biomedical and Life Sciences / Biotic factors / Demecology / Environment / fauna / Florida / Freshwater & Marine Ecology / Fundamental and applied biological sciences. Psychology / General aspects / Habitats / Life Sciences / Nature Conservation / ponds / Population density / predation / salt marshes / springs (water) / Studies / surface water level / temporal variation / traps / Variance analysis / Vegetation cover / Vertebrata / Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution / Water depth / Zoology