The energetics of Colpidium campylum Stokes with a note on the vertical distribution of Ciliophera in the mud of Loch Leven, Kinross

Abstract

The energetics of, the holotrich ciliate Colpidium campylum fed on the bacterium Moraxella sp. at 10°C, 15°C and 20°C were investigated. The parameter used for ascertaining growth. was the volume of protoplasm produced measured by means of a Coulter Counter with a mean cell volume converter attachment. Growth and consumption were measured in relation to food availability as indicated by the ratio of bacteria: protozoan. Mean cell volume variation and reproduction were also measured in relation to food availability and energy consumed. Protozoan and bacterial material were harvested by centrifugation and freeze-dried for dried weight determinations and calorimetry studies. The energy content of Colpidium and its food source was determined with a Phillipson microbomb calorimeter. Respiration was measured in a Warburg respirometer. Oxygen uptake in relation to population density and cell size was considered as well as the production of information concerning the heat lost during respiration for incorporation into energy budgets. Energy budgets of. two types were constructed: a 24-hour energy budget for an individual and the life-span or generation energy budget for an individual. Gross growth efficiencies, net growth efficiencies and assimilation efficiencies were considered in detail. In addition to laboratory work the vertical distribution of Ciliophora in the mud of Loch Leven, Kinross, Scotland, was also considered; three sites, two shallow and one deep, being sampled with a core sampler over a 12 month period.