Description of Longidorella (Saevadorella) caspica n. sp. (Dorylaimida: Nordiidae) from north Iran

This contribution provides the morphological and molecular identification of a new species of the genus Longidorella (Saevadorella). L. (S.) caspica n. sp., was recovered from the rhizospheric soil of grasses in Mazandaran province in the seashore of the Caspian Sea. It is characterized by females with a length of 788 to 874 mu m and a cephalic region with prominent papillae; and separated from the rest of the body by a remarkable constriction, an odontostyle of 32 to 33 mu m, vulva at 52.5 to 59.0%, and a tail of 33 to 38 mu m with a rounded tip. Males have 32 to 35 mu m long spicules of dorylaimoid form and five to seven ventral supplements ending at 48 to 55 mu m distance from cloacal pair. The new species was morphologically compared with seven nominal species viz. L. (S.) arenicola, L. (S.) cuspidata, L. (S.) magna, L. (S.) perplexa, L. (S.) saadi, L. (S.) saevae, and L. (S.) tharensis. It was further compared with similar species under the subgenus Longidorella (Enchodorella) viz. L. (E.) deliblatica and L. (E.) murithi. Besides morphological studies, molecular phylogenetic studies using partial sequences of D2 to D3 expansion fragments of 28S rDNA were performed for the new species and its phylogenetic relationships with other species and genera were discussed.