Redescription and molecular analysis of Neoechinorhynchus (Neoechinorhynchus) planilizai (Acanthocephala, Neoechinorhynchidae) from Planiliza abu (Mugilidae) in Iraq

Abstract

Neoechinorhynchus (N.) planilizai Al-Ayash, Gustinelli, Al-Nasiri, Caffara, 2021 was recently described from Planiliza abu (Heckel) in Iraq using line drawings. We update and complete that description using new ocular microscopy, SEM, and molecular analysis. New collections revealed structures that have not been previously reported including constricted proboscis, posterior hooks longer than middle hooks, bursa without sensory structures, spongy hypodermic tissue with lacunar channels under smooth cuticular surface, eggs with no fibrils, variable micropores, single ventral para-receptacle structure, large triangulate cephalic ganglion, a new papilla at the posterior tip of the proboscis receptacle, an anterior testis distinctly longer than posterior testis, short robust uterus a huge pot-shaped uterine bell, and two sets of ligament bundles emerging from the inner posterior tip of the trunk. No other taxonomic accounts of this species are known. The molecular analysis of N. planilizai is also described with sequences of the 18S nuclear ribosome generated and aligned with closely related sequences from GenBank database. Maximum likelihood and Bayesian inference analyses demonstrated that N. (N) planilizai was nested within neoechinorhynchid clades. Th e presence of N. (N) planilizai with other Middle East species in the tree allowed its characterization for the first time using morphological and molecular features.