Morphologic Variability and Value of the Characters Used for Species Identification in Paratrichodorus Siddiqi, 1974 (Nematoda: Trichodoridae)

Abstract

The variability of characters used for species identification in Paratrichodorus Siddiqi, 1974 are studied and their taxonomic value discussed. The thirteen characters considered valid for the genus database and conforming to the NEMAID identification computer program are: onchiostyle length, spicule length, number of precloacal supplements, presence of spermatheca, number of ventromedian cervical papillae, cloacal opening with bilobed lip, shape of vulva in ventral view, sperm structure, pharyngo-intestinal junction, presence of males, shape of vaginal sclerotizations, shape of spicules and geographical distribution. Additionally, three very specific characters included in the species identification system, although restricted to few species, are: a conoid tail shape with acute tip, the presence of medioventral body pores in female and the presence of two postcloacal papillae in the male.