Mitochondrial DNA dataset suggest that the genus Sphaerirostris Golvan, 1956 is a synonym of the genus Centrorhynchus Lühe, 1911

Abstract

Our present genetic data of Acanthocephala, especially the mitochondrial (mt) genomes, remains very limited. In the present study, the nearly complete mt genome sequences of Sphaerirostris lanceoides (Petrochenko, 1949) was sequenced and determined for the first time based on specimens collected from the Indian pond heron Ardeola grayii (Sykes) (Ciconiiformes: Ardeidae) in Pakistan. The mt genome of S. lanceoides is 13 478 bp in size and contains 36 genes, including 12 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs) and two ribosomal RNA genes (rRNAs). Moreover, in order to clarify the phylogenetic relationship of the genera Centrorhynchus and Sphaerirostris, and to test the systematic position of S. lanceoides in the Centrorhynchidae, the phylogenetic analyses were performed using Bayesian inference and maximum likelihood methods, based on concatenated nucleotide sequences of 12 PCGs, rRNAs and tRNAs. The phylogenetic results further confirmed the monophyly of the order Polymorphida and the paraphyly of the order Echinorhynchida in the class Palaeacanthocephala. Our results also challenged the validity of the genus Sphaerirostris (Polymorphida: Centrorhynchidae) and showed a sister relationship between S. lanceoides and S. picae (Rudolphi, 1819).

Description and molecular analysis of an Italian population of Centrorhynchus globo caudatus (Zeder, 1800) Lühe, 1911 (Acanthocephala: Centrorhynchidae) from Falco tinnunculus (Falconidae) and Buteo buteo (Accipitridae)

“…20). The bend at the posterior end of the male trunk makes the gonopore appear subterminal. Nelson & Ward (1966) examined four juvenile specimens from the long-eared hedgehog, H. auritus Gmelin, from Egypt, showing a ‘nearly cylindrical’ proboscis also widest anteriorly (their Fig. 6), with unusually few (26–28) longitudinal rows of 20–22 hooks each. Only Ward (1964) and the present paper document longer ventral and shorter dorsal proboscis hooks (table 3).…”

“…Scale bar indicates expected number of substitutions per site. Outcomes of phylogenetic analyses based on mtDNA data (Muhammad et al, 2020) suggest that Sphaerirostris is a sister group of Centrorhynchus aluconis, conforming a sub-clade within Centrorhynchus, which would, therefore, be a paraphyletic taxon. Our results seem to agree with this suggestion; however, the weak bootstrap support and the nucleotide differences associated to these relationships in phylogenetic analyses hamper its confirmation.…”

“…The two cox1 available sequences of Sphaerirostris lanceoides were obtained from cystacanths present in amphibians and ardeid birds (i.e. Ardeola grayii), respectively (Kang & Li, 2018;Muhammad et al, 2020), and the only cox1 available sequence of Sphaerirostris picae was obtained from adults infecting the corvid Dendrocitta vagabunda (see Muhammad et al, 2019). Indeed, while Sphaerirostris mostly infects passerine birds, Centrorhynchus mainly infects birds of prey instead.…”

“…Nelson & Ward (1966) examined four juvenile specimens from the long-eared hedgehog, H. auritus Gmelin, from Egypt, showing a ‘nearly cylindrical’ proboscis also widest anteriorly (their Fig. 6), with unusually few (26–28) longitudinal rows of 20–22 hooks each.…”

“…Insects serve as intermediate hosts for species of Centrorhynchus , while amphibians, reptiles and occasionally insectivorous mammals serve as second intermediate or paratenic hosts. Nelson & Ward (1966) collected juvenile specimens of C. globocaudatus from the long-eared hedgehog, Hemiechinus auritus Gmelin, in the Egyptian El Tahreer Province, and Torres & Puga (1966) collected cystacanths of specimens of Centrorhynchus sp. from two species of frogs in Chile – Eupsophus calcaratus Günther and Eupsophus roseus Dumeril.…”