Electrophoretic and morphological analysis of Paramacropostrongylus typicus (Nematoda: Strongyloidea), with the description of a new species, Paramacropostrongylus iugalis, from the eastern grey kangaroo Macropus giganteus

An allozyme study of four populations of Paramacropostrongylus typicus from Macropus fuliginosus and M. giganteus detected the presence of a distinct species, Paramacropostrongylus iugalis n. sp., which is described from the stomach of the eastern grey kangaroo Macropus giganteus. The description is based on samples possessing fixed allelic differences at 10 of 37 enzyme loci examined, minor morphological differences from its congener P. typicus in M. fuliginosus, and presumed limitation to a single host species, M. giganteus. Its differentiation from P. typicus is more clearly demonstrated by biochemical characters than by morphological ones. The two parasite species probably co-speciated with their hosts.