Naked Amoebae in Biofilms Collected from a Temperate Freshwater Pond

Abstract

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.

New insights on the evolutionary relationships between the major lineages of Amoebozoa

“…Indeed, presently, naked amoebae are known as one of the primary grazers of bacterial biofilms 67 – 69 . Moreover, they not only just graze and phagocytize prey in the mats, but also disrupt them, making their content available for other organisms 70 , 71 . Finally, in addition to the advantage of feeding on bacterial mats 72 , 73 , it is also possible that an increase in body size alleviated pressure of predation by other organisms on the last Amoebozoan common ancestor (LACA), which for some time provided it an adaptive advantage and allowed rapid proliferation and differentiation of Amoebozoa in the mid-Proterozoic environment.…”

New Insights on the Evolutionary Relationships Between the Major Lineages of Amoebozoa

“…Indeed, presently, naked amoebae are known as one of the primary grazers of bacterial biofilms [64][65][66] . Moreover, they not only just graze and phagocytize prey in the mats, but also disrupt them, making their content available for other organisms 67,68 . Finally, in addition to the advantage of feeding on bacterial mats 69,70 , it is also possible that an increase in body size alleviated pressure of predation by other organisms on the last Amoebozoan common ancestor (LACA), which for some time provided it an adaptive advantage and allowed rapid proliferation and differentiation of Amoebozoa in the mid-Proterozoic environment.…”

The food web perspective on aquatic biofilms

“…Seven different genera of naked amoeba were found in riverine biofilms by Hunt and Parry (). Anderson () recorded 30 morphospecies in biofilm samples from a pond in northern New York, USA. Densities ranged from 109 to 136 individuals/cm 2 .…”