Growth, reproduction and longevity in nematodes from sewage treatment plants

The growth, reproduction and longevity of Diplogasteritus nudicapitatus, Paroigolaimella bernensis and Rhabditis curvicaudata were investigated under conditions of excess food within the temperature range 5°C-20°C. In all three species growth rate increased with temperature, and in D. nudicapitatus and R. curvicaudata the adult size attained varied significantly with temperature. P. bernensis did not reproduce at 5°C, but showed a progressive increase in reproductive output at higher temperatures. D. nudicaitatus showed increased egg production as temperature increased while R. curvicaudata had maximum egg output at 10°C. Longevity is temperature dependent, decreasing with higher temperatures. Virgin females survived for longer than reproducing females. The data indicate that while D. nudicapitatus and P. bernensis are thermophilic species, R. curvicaudata is adapted to lower temperatures.