Molecular data confirm the species status of Neoechinorhynchus personatus and N. yamagutii (Acanthocephala, Neoechinorhynchidae) from the Atlantic and Pacific grey mullets (Teleostei, Mugilidae)

Abstract

Molecular Data Confi rm the Species Status of Neoechinorhynchus personatus and N. yamagutii (Acanthocephala, Neoechinorhynchidae) from the Atlantic and Pacifi c Grey Mullets (Teleostei, Mugilidae). Sarabeev, V., Tkach, Ie., Sueiro, R. A., Leiro, J. -Neoechinorhynchus is known to be the most diverse acanthocephalan taxon with worldwide distribution; its species are characterized by uniformity of anatomical organization. Th e taxonomic status of Neoechinorhynchus agilis s. l. from grey mullets was recently reviewed that resulted in description of two new species, Neoechinorhynchus (Hebesoma) personatus and Neoechinorhynchus (Hebesoma) yamagutii. In the current study,18S rRNA partial gene sequences were obtained to molecularly characterize N. (N.) agilis, N. (H.) personatus and N. (H.) yamagutii from grey mullets, Chelon labrosus and Mugil cephalus, in the North-East Atlantic, the Japan, Azov and Mediterranean Seas. Th e universal (F-566 and R-1200) and specifi c eukaryotic set primers were used to amplify specimens from each species of Neoechinorhynchus. It has been found that three species can be clearly recognized using universal primers, which allow to obtain sequences of 590 to 664 bp in length. Th e genetic divergences estimated between three species sequenced here were relatively high, at ranged between 2.08 and 6.57 %. Phylogenetic analysis demonstrates that the studied species of Neoechinorhynchus from grey mullet fi sh share common ancestor, despite their diff erent geographic location, and are closely related. Th e terminal position of N. (N.) agilis and N. (H.) personatus on the evolution tree and the low genetic divergence found between them suggests the recent emergence of this group and that the colonization of the North-East Atlantic and the Mediterranean regions could represent a single event. Our phylogenetic analysis, which included several species of the subgenera Neoechinorhynchus and Hebesoma, showed that the latter is a polyphyletic taxon.

On theNeoechinorhynchus agilis(Acanthocephala: Neoechinorhynchidae) complex, with a description ofNeoechinorhynchus ponticusn. sp. fromChelon auratusin the Black Sea

“…Van Cleave [36,37] suspected that N. agilis was restricted to the Mediterranean, but this is now known not to be. For example, species presumed to be N. agilis before the establishment of the species complex concept studies by Tkach et al [35], Sarabeev et al [31] and ours (this paper) were reported from M. cephalus in Taiwan [32], in the Indian Ocean near Tamil Nadu [17], and in Guyana [26], as well as in Japan, Scotland, and North America. Other observers including Linton [19][20][21], Van Cleave [36,37], Meyer [23], Yamaguti [40,41], Petrochenko [24], Gaevskaya et al [10], and Tepe and Oguz [34] reported N. agilis from at least 10 species of fish in the Black Sea and the Mediterranean, among other locations off the coasts of Scotland, North America, and Japan.…”

“…Tkach et al [35] and Sarabeev et al [31] (Table 2). In addition, the shorter lemnisci in N. ponticus occupy a considerably smaller trunk space distant from the anterior testis (Fig.…”

“…and other species of the Neoechinorhynchus supports the morphological observation indicating it is an independent species. Sarabeev et al [31] showed that N. agilis, N. personatus and N. yamagutii are three independent species using the same phylogenetic analysis of partial sequences of the 18S rRNA gene. Our data, consistent with results of other studies [22,31], indicated genetic divergences among these three species were relatively high, at the range between 2.18% and 6.60%.…”

“…Sarabeev et al [31] showed that N. agilis, N. personatus and N. yamagutii are three independent species using the same phylogenetic analysis of partial sequences of the 18S rRNA gene. Our data, consistent with results of other studies [22,31], indicated genetic divergences among these three species were relatively high, at the range between 2.18% and 6.60%. The phylogenetic analysis of the partial 18S rDNA gene illustrated that our sequence of N. personatus clustered with N. personatus isolates from Ukraine.…”

“…Other observers including Linton [19][20][21], Van Cleave [36,37], Meyer [23], Yamaguti [40,41], Petrochenko [24], Gaevskaya et al [10], and Tepe and Oguz [34] reported N. agilis from at least 10 species of fish in the Black Sea and the Mediterranean, among other locations off the coasts of Scotland, North America, and Japan. This species complex appears to be widely distributed in mullets from the Atlantic and Pacific oceans ( [31,35], among others). Altogether, descriptions by the above cited authors gave an extreme range of variation in taxonomically important traits.…”