Morphological and genetic information was used to determine the species identity and relationships of four species of nematodes from the Victoria Land coast, Antarctica; and between laboratory and field populations of Panagrolaimus davidi Timm. The 18S and D3 expansion segments of 28S rRNA were successfully amplified from the four species: Scottnema lindsayae Timm, Plectus murrayi Yeates, Eudorylaimus spp. and Panagrolaimus davidi. The four species from field populations mapped to three different nematode clades, indicating that if they are survivors in, rather than colonizers of, Antarctica they originate from several Gondwanan ancestors. The laboratory culture of P. davidi is shown to be a different species to that of the field samples of P. davidi, which were genetically identical to each other. There are several possible explanations for this observation, which require further investigation.
