SEM observations and morphometrics of Hemicycliophora belemnis Germani & Luc, 1973 and Paratylenchus bukowinensis Micoletzky, 1922 (Nematoda: Criconematoidea) from Iran

Abstract

The natural occurrence of a rare species, Hemicycliophora belemnis, and a more common Paratylenchus bukowinensis, in the Dez forest near Ahwaz, Iran, is reported. Scanning electron microscopy (SEM) morphology and morphometry of populations of the two nematode species are detailed and compared with those of earlier reports. The population of Hemicycliophora belemnis was distinguished by a progression in variation in pattern of the lateral eld present in individual females as opposed to only one type of variation in individual females according to earlier reports. Other differences included a lower number of tail annules, two to four vs two head annules in females, and in males, two longitudinal lateral incisures, a shorter tail and ratio of bursa annule width to corresponding body annule width. New information is given on the amphid apertures and head annules. The population of Paratylenchus bukowinensis was distinguished from earlier reported descriptions of the same species by greater mean values for body length, stylet length, distance of excretory pore from anterior end, as well as annulations extending to tail terminus, details of the vulval aps, and absence of males. These differences were attributed to geographical in uences and not deemed signi cant to warrant the creation of new species. Furthermore, the differences are indicative of the degree of variation and reliability of certain morphological and morphometrical values used in the differential diagnoses of the species.