The Life Cycle of the Antarctic Nematode Plectus murrayi Under Laboratory Conditions

摘要

We study and describe the life cycle of Plectus murrayi, a free-living, bacterivorous soil nematode endemic to terrestrial Antarctica.The study was performed at 158C, a temperature identi?ed as optimal for growth rate studies in the laboratory.Under these conditions, we observed that the ?rst molt occurs in the egg, and second-stage juveniles hatch 12 to 14 d after egg laying.Individuals undergo three subsequent molts to become adults 23 to 26 d after hatching with a ?nal average length of 950 mm.Egglaying begins 41 to 43 d after hatching, resulting in an egg-to-egg life cycle ranging from 53 to 57 d under our experimental conditions.Considering that the average soil temperature during austral summers in the McMurdo Dry Valleys is only a few degrees abovefreezing,itishighlylikelythatmany,ifnotmostoftheseanimals,requiremorethan1yrtocompletetheirentirelifecycle.Our study supports other research that establishes P.murrayi as an important model organism for studying adaptation to extreme environmental stress.