Three new species of Neoechinorhynchus (Acanthocephala: Neoechinorhynchidae) from fresh-water fish collected from Tigris River, Iraq

Three new species of Neoechinorhynchus are described from freshwater fish of Tigris River, at Salah Al-Din province, mid Iraq, namely Neoechinorhynchus tigrisensisn. sp. from Shilik Leuciscus vorax (Heckel) and Brond-snout Chondrostoma regium (Heckel), N. planilizain. sp. from Abu mullet Planiliza abu (Heckel) and Tigris catfish Silurus triostegus (Heckel) and N. barbin. sp. from Mesopotamian barb Capoeta damascina (Valenciennes). The first two new species shared the para-receptacle structure (PRS) with seven nominal valid species of the genus Neoechinorhynchus but they differed in other taxonomic traits, while the third new species shared the vaginal vestibular muscles (para vaginal patch) at the end of female trunk with N. spiramuscularis Amin, Heckmann & Ha, 2014 and N. zabensis Amin, Abdullah & Mhaisen, 2003 but differed for further morphological features. Proboscis hooks of middle and posterior circles in N. barbin. sp. are remarkably bigger than in the other two new species (N. tigrisensis and N. planilizai) while the hooks in first circle is almost similar in the three species. Furthermore, N. tigrisensisn. sp. and N. planilizain. sp. differ from some marine species by having smallest hooks size at anterior circle, with different shape and size of hooks. The three new species reported in the present study are compared with other eight species of Neoechinorhynchus reported so far from fish in Iraq. This work contributes to increase the knowledge on the biodiversity of fish parasites all over the world, especially for acanthocephalans.