Validity of Pampus liuorum Liu & Li, 2013, Revealed by the DNA Barcoding of Pampus Fishes (Perciformes, Stromateidae)

Abstract

The genus Pampus contains seven valid species, which are commercially important fishery species in the Indo-Pacific area. Due to their highly similar external morphologies, Pampus liuorum has been proposed as a synonym of Pampus cinereus. In this study, partial sequences of COI (582 bp) and Cytb (1077 bp) were presented as potential DNA barcodes of six valid Pampus species and the controversial species P. liuorum. A species delimitation of the seven Pampus species was performed to verify their validities. Explicit COI barcoding gaps were found in all assessed species, except for P. liuorum and P. cinereus, which resulted from their smaller interspecific K2P distance (0.0034–0.0069). A Cytb barcoding gap (0.0200) of the two species was revealed, with a K2P distance ranging from 0.0237 to 0.0277. The longer Cytb fragment is thus a more suitable DNA barcode for the genus Pampus. In the genetic tree, using concatenated Cytb and COI sequences, the seven species reciprocally formed well-supported clades. Species delimitations with ABGD, GMYC, and bPTP models identified seven operational taxonomic units, which were congruent with the seven morphological species. Therefore, all of the seven analyzed species, including P. liuorum, should be kept as valid species.

Species diversity and distribution of genus Pampus (Pelagiaria: Stromateidae) based on global mitochondrial data

“…With recent efforts, Pampus cinereus (Bloch, 1795), Pampus candidus (Cuvier, 1829), and Pampus punctatissimus (Temminck & Schlegel, 1845) are resurrected as valid species; Pampus liuorum Pampus minor Liu andLi, 1998, are published as new species (Liu and Li, 1998a;Liu and Li, 1998b;Liu et al, 2013a;Liu et al, 2013b;Liu and Li, 2013), demonstrating that the genus Pampus is actually a more diverse group. Our previous study, Wei et al (2021), confirmed the validities of seven species in the genus Pampus, viz., P. argenteus, P. candidus, P. chinensis, P. cinereus, P. liuorum, P. minor, and P. punctatissimus. However, validities of several species names, e.g., P. echinogaster and Pampus nozawae (Ishikawa, 1904), and Pampus griseus (Cuvier, 1833), remained unclear.…”

“…There have been concerted efforts to study their reproductive biology, evolution, and population genetics of the Pampus species (e.g., Dadzie et al, 2000;Gupta, 2020;Fan et al, 2022). Nevertheless, the chaotic taxonomies and misidentifications have hindered our understanding of the biology and evolution of this genus (Liu et al, 2013a;Radhakrishnan et al, 2019;Wei et al, 2021).…”

“…Due to the highly similar external morphology of the Pampus species, misidentifications frequently occur and greatly affect the understanding of the taxonomy and species distributions of the genus (Wei et al, 2021). Haedrich (1967) recognized three species in the genus Pampus, i.e., Pampus argenteus (Euphrasen, 1788), Pampus echinogaster (Basilewsky, 1855), and P. chinensis, and assigned many species names as synonyms of the three species.…”

“…Over 1,500 DNA sequences of the genus Pampus have been deposited on GenBank and the Barcoding of Life Database (BOLD) with well-documented sampling localities in the databases and published studies, which provided a suitable dataset for studying species diversity and distribution of the genus Pampus. However, misidentification of the Pampus sequences frequently occurs (Roul et al, 2021;Wei et al, 2021), which greatly impedes the progress to clarify their taxonomy and distributions. In our previous study, Wei et al (2021) provided reliable barcodes of cytochrome oxidase unit I (COXI) and cytochrome b (Cytb) from 74 specimens of seven Pampus species (i.e., P. argenteus, P. candidus, P. chinensis, P. cinereus, P. liuorum, P. minor, and P. punctatissimus).…”

Diversifying of Two Pampus Species across the Indo–Pacific Barrier and the Origin of the Genus

“…Divya et al [21] described the Pampus species collected from the Arabian Sea as a new species, P. candidus, but we think further scrutiny should be made to split more species from P. cinereus lineages before distinct morphological characters are identified. On the other hand, P. liuorum, a controversial Pampus species, was defined as a synonym of P. cinereus in our previous study [15], but a recent study justified P. liuorum as a valid species using two mitochondrial DNA barcodes [66]. In their Cytb trees, P. cinereus and P. liuroum sampled in the western Pacific were separated in two lineages, which was different from our result, but their COI tree corroborated our result that P. cinereus and P. liuroum are not reciprocal in monophyletic.…”