Biogeography and variations in allopatric populations of Distolabrellus veechi Anderson, 1983 (Nematoda: Rhabditidae)

A detailed description of Distolabrellus veechi (syn. nov. D. pakistanensis) is given based on variations observed in different populations collected from India and Korea, and comparisons made with those reported from Arizona and Argentina. The populations, which showed a great degree of morphometric overlap and a continuous range in variation, could not be differentiated from the type population of D. veechi. The relationships of the populations were studied using morphological data subjected to cluster analysis. The characteristics of the species and its relationship with Teratorhabditis are also discussed. Biogeographical information revealed an interesting trend of distribution for the species, i.e., between 22-55° north and south of the equator.