Redescription of <i>Laimydorus siddiqii</i> Baqri &amp; Jana, 1982 (Dorylaimida: Dorylaimidae) with its first molecular study

A nematode population (SF7) belonging to the genus <i>Laimydorus siddiqi</i>, 1969, was isolated from the soils of sugarcane fields in the Haridwar district of Uttarakhand, India. Based on morphological, morphometrical, and molecular studies, the nematode was identified as <i>Laimydorus siddiqii</i>. This work represents the first molecular report of this species. <i>Laimydorus siddiqui</i> has a 2.6 to 3.08 mm long body, with a truncate lip region, linear odontostyle, double guiding ring, female genital system amphidelphic, longitudinal vulva, and females with a very long, filiform tail. Males have 56 - 63 μm long spicules and 28 - 29 ventromedial supplements. Molecular analyses utilizing segments of the 28S rDNA placed <i>Laimydorus siddiqi</i> in a clade with <i>Laimydorus zehsaziani</i> from Iran and other representatives of the genera <i>Labronema</i>, <i>Dorylaimus</i>, <i>Prodorylaimus</i>, <i>Calcaridorylaimus</i>, <i>Mesodorylaimus</i>, and <i>Aporcelamellus</i>. However, there is no available 18S rRNA sequence of any known species of <i>Laimydorus</i>, and our sequence is the first SSU rRNA of this genus. These molecular findings support the taxonomic positioning of <i>Laimydorus siddiqui</i> within the broader phylogenetic framework of the family Dorylaimidae, highlighting its relationships with closely related genera.