Abstract

In order to identification of free-living and bacterivorous nematodes belonging to the family Cephalobidae, about 200 samples were collected from natural areas of Semnan province during 2007 to 2009. In this study two species of the genus Eucephalobus Steiner, 1936 viz. E. mucronatus (Kozlowska & Roguska-Wasilewska, 1963) Andrássy, 1967 in association with rhizosphere of a forest tree and carrot and E. striatus (Bastian, 1865) Thorne, 1937 in association with willow, soil and river were isolated and identified. Both species having short and acute labial probolae while E. mucronatus having cylindrical tail with mucron (vs E. striatus having longer tail with prominent ending). In two mentioned species, stoma including cheilostome, gymnostome and stegostome, spermatheca offset and postuterine sac short. Description, measurements and drawings are provided for these species. This is the first record of these species from Semnan province and second report from Iran and males of E. striatus are described from Iran for the first time