A multivariate analysis of morphometric characters of Heterorhabditis species (Nemata: Heterorhabditidae) and the role of morphometrics in the taxonomy of species of the genus.

A multivariate analysis on the morphometrics of 7 Heterorhabditis species was conducted to review the status of the traditional morphometric characterization methods for differentiating species of these nematodes. Results from this study showed consistency in the selection of morphometric characters for discriminating among males and infective juveniles of Heterorhabditis species. For the males, testis reflexion (TREF) and total length (LENGTH) were the variables that contributed most in the discrimination among the different species, and for the infective juveniles, tail length (TAILL) and total length (LENGTH) were the variables that contributed most. Therefore, we consider that these morphometric characters are useful and reliable, and that they should be used for the identification of Heterorhabditis species/isolates.