Naked amoebae in biofilms collected from a temperate freshwater pond

Biofilms collected on Plexiglass substrates, from a freshwater pond in northern New York State, were examined microscopically for naked amoebae densities, sizes, diversity, and estimated C-biomass. Five samples were obtained during summer 2006 and 2007. The densities ranged from 109 to 136/cm(2) biofilm surface and 285 to 550/mg biofilm dry weight. Sizes ranged from 13 to 200 μm. Diversities ranged from 4.23 to 4.55. C-biomass ranged from 64 to 543 ng C/cm(2) and 125 to 1,700 μg C/g dry weight. Thirty morphospecies were identified among the five samples, including very large amoebae in the range of 100-200 μm. Large amoebae (≥ 50 μm) accounted for the largest proportion of the C-biomass.