Morphological and molecular characterisation of sp. nov. and Siddiqi 1959 (Nematoda: Longidoridae) from southern Iran.

Two species, one new and one known, were found from Bushehr province, southern Iran, and are herein described based on morphological and molecular data. These include sp. nov. and , both belonging to the ' non- group'. The new dagger nematode is characterised by a body length of 3.54-5.00 mm, a lip region separated from the rest of body by a depression, odontostyle 128-148 μm long, 60-89 μm long odontophore, guiding ring at 107-138 μm from anterior end, female tail rounded to dorsally more convex with small bulge and four juvenile stages. Males have one pair of cloacal and three to five ventromedian single supplements. The new species belongs to morphospecies non- group 5, characterised by having two equally developed female genital branches with uterine differentiation in the form of pseudo-Z-organ along with the rhomboid-shaped crystalloid bodies, and a short, rounded tail ending in a peg. The polytomous identification codes of the new species are A4, B2, C5a5b, D6, E56, F4(5), G23, H2, I34, J5a5b, K3, L2. Morphologically, the new species comes close to several known species (namely, , , , , , and ) belonging to morphospecies group 5. The morphological differences of the new species and the aforementioned species are discussed. The second recovered species, , belongs to the same group and has a pseudo-Z-organ in the shape of globular bodies close to and short, conical, distinctly digitate tail. Integrative diagnosis was completed using molecular data obtained from partial sequences of the D2-D3 region of 28S rDNA, ITS1 rDNA, 18S rDNA, and mtDNA genes.