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

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.