An energy budget for the free-living nematode Pelodera (Rhabditidae)

The energetics of a population of a free-living nematode Pelodera sp. that feeds on bacteria were studied in the laboratory. A budget was drawn up for Pelodera feeding on Escherichia coli labelled with ¹⁴C. Measurements were also made of population growth, respiration and feeding rate. In vitro, Pelodera ingested on average 37.0×10^-2 J h^-1 mg^-1 dry weight, of which 13.7×10^-2 J h^-1 mg^-1 dry weight were respired, 15.0×10^-2 J h^-1 mg^-1 dry weight were excreted and 8.3×10^-2 J h^-1 mg^-1 dry weight were retained in growth. The measurements of feeding rate indicated that the values for the percentage energy flow depended partly on the concentration of bacteria present. These results are discussed and an energy budget is calculated for bacterial-feeding nematodes in bog soil, using published field data.