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

• Published in: Nematology : international journal of fundamental and applied nematological research 2004, Vol.6 (6), p.883-890
• Main Authors: Brown, Ian M, Wharton, David A, Millar, Russell B
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Biological and medical sciences; cold zones; Demecology; dormancy; free-living nematodes; Fundamental and applied biological sciences. Psychology; INTRINSIC RATE OF NATURAL INCREASE; life history; Panagrolaimus; POPULATION GROWTH; Protozoa. Invertebrata; R-K-A SELECTION; reproduction; temperature; THERMAL TIME; threshold temperature; THRESHOLD TEMPERATURES
• ISSN: 1388-5545; 1568-5411; 1388-5545
• DOI: 10.1163/1568541044038641

Abstract Panagrolaimus 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.