Acanthocephalans from fishes and amphibians in Vietnam, with descriptions of five new species

Abstract

Eight species of acanthocephalans are reported, and five are new. Specimens of Neoechinorhynchus (Hebesoma) manubrianus Amin, Ha & Ha, 2011 were similar to the original description. Neoechinorhynchus (Hebesoma) spiramuscularis n. sp. (Neoechinorhynchidae), from Xenocypris davidi, has a unique proboscis receptacle wrapped in a spiral muscular layer, and an undulating flask-shaped lemnisci, as well as double para-receptacle structures. Heterosentis mongcai n. sp. (Arhythmacanthidae), from Acreichthys sp., has a small fusiform trunk with an unarmed cone and anterior trunk spines, and a proboscis with two circles of rooted apical hooks and 3–4 circles of rooted posterior spines as well as a para-receptacle-like structure at the posterior end. The poorly known Filisoma indicum Van Cleave, 1928 is fully described and illustrated for the first time. Acanthocephalus parallelcementglandatus n. sp. (Echinorhynchidae), from Clarias batrachus, is distinguished from other species of Acanthocephalus by its small fusiform trunk and parallel tubular cement glands. Pseudoacanthocephalus coniformis n. sp. (Echinorhynchidae), from Hylarana sp., is distinguished from other species by having an anterior trunk collar and staggered prominent filiform cement glands, among other features. Cathayacanthus spinitruncatus n. sp. (Rhadinorhynchidae), from Leiognathus equulus, is distinguished from the only two known species of the genus by having a very long and slender proboscis with more than 50 hooks per row and a totally spined trunk. The generic diagnosis of Cathayacanthus Golvan, 1969 is emended. Rhadinorhynchus johnstoni Golvan, 1969 (Rhadinorhynchidae) perfectly fits the only complete description of that species from the Fiji Islands.

The molecular profile of Paratrajectura longcementglandatus Amin, Heckmann et Ali, 2018 (Acanthocephala: Transvenidae) from percid fishes in the marine waters of Iran and Iraq

“…More sequence data from other geographical isolates using more gene targets will be useful for exploring the phylogenetic relationships among species. On the other hand, using of molecular tools for identification of acanthocephalan species is still scarce due to the lack of sequences of different genera of acanthocephalans in GenBank (Amin et al, 2013;Salgado-Maldonado, 2013;Weaver & Smales, 2013;Amin et al, 2014;Smales, 2014;Gomes et al, 2015;Steinauer & Nickol, 2015). More molecular studies are recommended in order to elucidate acanthocephalans classification.…”

A New Species of the Acanthocephalan Genus Filisoma (Cavisomidae) from Perciform Fishes in Rio de Janeiro, Brasil

“…The molecular data analyzed also suggest that families of Palaeacanthocephala must be reevaluated, since the delineation of monophyletic families was not clear in any of the topologies obtained, especially for species of Echinorhynchidae. The lack of sequences of different genera of Acanthocephala demonstrates that the use of molecular tools in defining species of Acanthocephala is still scarce and a large number of studies still describe and redescribe species based only on morphology [2,4,[28][29][30][31][32]. For Cavisomidae, for example, there are genetic sequences of only three species available in the GenBank, all of them from the genus Filisoma (F. bucerium, F. rizalinum and now F. caudata n.…”

“…Acanthocephalans of the genus Filisoma Van Cleave, 1928 have been described from fish from tropical and subtropical waters, including species of the family Kyphosidae Jordan, 1887 [1,2]. Twelve species are recognized within the genus [3] [2,4,5]).…”

Descriptions of acanthocephalans, Cathayacanthus spinitruncatus (Rhadinorhynchidae) male and Pararhadinorhynchus magnus n. sp. (Diplosentidae), from marine fish of Vietnam, with notes on Heterosentis holospinus (Arhythmacanthidae)

“…Twenty species of acanthocephalans in 5 families were collected more recently from fishes in the Pacific and amphibians in central Vietnam, in 2016 and 2017. In the present report, we describe males of Cathayacanthus spinitruncatus Amin, Heckmann & Ha, 2014 (Rhadinorhynchidae) previously known from females only [ 13 ], a new species of the genus Pararhadinorhynchus Johnston & Edmonds, 1947 (Diplosentidae), and record Heterosentis holospinus Amin, Heckmann & Ha, 2011 in a new host and locality. For a better understanding of the chemical elements of hooks and their relationship to hook structure, intact and gallium-cut hooks of P. magnus were scanned with X-ray (EDAX) and analyzed for percent chemical elements in various parts of the hooks.…”

“…Most of the recent taxonomic work on the Acanthocephala from Vietnam has been reported by the Amin-Heckmann-Ha team since 2000; see Amin & Ha [ 2 , 3 ] and Amin et al [ 4 – 7 , 9 – 13 ]. Only three other species of Rhadinorhynchus and one species of Gorgorhynchus were previously reported from marine fishes in Vietnam by Arthur and Te [ 14 ].…”