Descriptions of two new species of Aporcelinus Andrássy, 2009 (Nematoda: Dorylaimida: Aporcelaimidae) and a new record from Iran

The genus Aporcelinus Andrássy, 2009 currently includes 33 valid species worldwide, although its diversity in Iran remains insufficiently explored. During nematological surveys conducted in forest habitats of northern Iran, three populations of Aporcelinus were recovered from soil and moss samples and studied using detailed morphological and morphometric analyses. The study revealed two new species, Aporcelinus nebulosus sp. nov. from Abr Forest, Semnan Province, and A. taromensis sp. nov. from Tarom region, Zanjan Province, as well as the first Iranian record of A. infundibulicaudatus (Andrássy 1991) Andrássy, 2009 from Saravan Forest Park, Gilan Province.

Aporcelinus nebulosus sp. nov. is characterized by a 1.85–2.10 mm long body, lip region offset by constriction, odontostyle 22–25 μm long, simple tube-like uterus, conical tail with finely rounded terminus and inconspicuous dorsal concavity, spicule 73 μm long, and 13 ventromedian supplements. Aporcelinus taromensis sp. nov. is characterized by a 1.97–2.42 mm long body, lip region offset by constriction, odontostyle 21–23 μm long, tripartite uterus, conical tail with finely rounded tip and distinct hyaline region (48–68 μm, c′ = 1.4–2.0), spicules 73–86 μm long, and 16–21 ventromedian supplements.

Detailed descriptions, morphometrics, line drawings, and photomicrographs are provided for all studied populations, and the new species are compared with their closest congeners. An updated account of the genus Aporcelinus in Iran is also presented.