اولین گزارش از جنس Sychnotylenchus (Tylenchomorpha: Anguinidae) از ایران

During samplings of decaying trees from Golestan province, north Iran, the genus Sychnotylenchus, a nematode associated with insects, was identified. Iranian population of the genus Sychnotylenchus is characterized by small to middle-sized body length ranging from 620-813 and 473-663 μm for females and males, respectively, two lateral sectors smaller than the other four sector, cylindrical body, lateral field with 6-8 lines, placement of excretory pore at level with, or anterior to median bulb in most individuals, spermatheca oval- or roundish-rectangular, often filled with rounded and large sperm, crustaformeria consisting of four rows, each row with four large and rounded cells, position of the vulva at (88.5-90.2 %) from anterior body end, PUS long, rounded, with thin wall, tail short, broad, with the rounded terminus, 18 μm long, not mucronate. Spicules approximately equal to tail length, typical of anguinid, i.e., consisting of roundish-squared manubrium, smoothly arcuate ventrally, gubernaculum one-third the length of spicules and bursa extended to the end of the tail (peloderan). The new species is morphologically very similar to S. hibisci, but is distinguished by having 16 cells versus 24 cells in crustaformeria, which is one of the important factors in the differentiation of species of this genus. The molecular phylogenetic relationships of the studied species with S. hibisci were reconstructed using partial ribosomal DNA sequences of small and large subunits (LSU and SSU), the results confirming the differences between the two species. Therefore, the present population is proposed as the first report of genus from Iran..