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/cm² 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/cm² 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.