Morphological and molecular characterisation of Ektaphelenchoides tonekabonensis n. sp. (Rhabditida: Ektaphelenchinae) from northern Iran

Abstract

Summary Ektaphelenchoides tonekabonensis n. sp. is described and illustrated based upon morphological, morphometric and molecular characters. The new species is characterised by 476-659 μm long females, lip region broad and continuous with body contour, two weak lateral bands barely visible in lateral view and cross section, needle-like stylet with its conus forming ca 50% of the total length and with a very narrow lumen in the shaft, excretory pore located just opposite the metacorpus base or slightly posterior, a dense (sclerotised) mass just anterior to the vagina, a short post-uterine sac 5-7 μm long, elongate conoid distal body region ending in a long filiform part, males common with a dorsally convex conical tail ending to a filiform tip, 7-8 μm long spicules with a small projection at the capitulum close to the condylus, its tip posteriorly bent, and five precloacal + caudal papillae. Based upon morphological similarities and phylogenetic affinities, it is similar to six known species of the genus, namely: E. attenuata, E. caspiensis, E. fuchsi, E. kelardashtensis, E. musae, and E. ruehmi. Ektaphelenchoides caspiensis is typologically most similar to the new species and can be separated based on vulval position, excretory pore position and male tail characters. The next most similar species, E. kelardashtensis, has a longer stylet and posteriorly located excretory pore. Comparisons with the other aforementioned species and typologically similar species under Seinura are also discussed. Molecular phylogenetic analyses were performed using Bayesian inference (BI) based upon two partial small and large subunit ribosomal DNA (SSU and LSU rDNA D2-D3) sequences and the phylogenetic affinities of the new species in both phylogenies were discussed.