The influence of temperature on the life history of the Antarctic nematode Panagrolaimus davidi

Abstract

AbstractPanagrolaimus davidi is a free-living microbivore, associated with moss and algal patches in coastal regions around Ross Island, Antarctica. In laboratory experiments, temperature had a major influence on P. davidi life history parameters. The optimal temperature occurred between 25 and 30°C and the temperature at which population growth ceased was estimated at 6.8°C. Threshold temperatures for developmental processes were in the range 4.1°C (for egg incubation) to 7.6°C (for generation time). The life history strategy of P. davidi shows r-selected features and is more similar to temperate free-living nematodes than to other polar species, which show K-selected features. In the Antarctic, P. davidi is forced to remain dormant for long periods and growth occurs intermittently when conditions allow, suggesting A selection. The life history of P. davidi thus exhibits both A and r-selected features.