Diversity and distribution of cryptic species within the Mugil cephalus species complex in Vietnam

Abstract

Mugil cephalus sensu lato is a globally distributed complex of cryptic species whose distribution range and evolutionary history remains largely unknown. In the North West (NW) Pacific three species have been identified genetically among fish described morphologically as M. cephalus. Their distribution ranges are largely parapatric and has been proposed to mirror different thermal preferences. To date, few samples have been analyzed from South China Sea, which limits inferences on the evolutionary history of the species complex. We sampled fish identified morphologically as M. cephalus along Vietnamese shores and characterized them using the sequence polymorphism of two mitochondrial genes, the cytochrome oxidase I and cytochrome b. This demonstrated that all three species described in the NW Pacific are present in both northern and southern Vietnamese waters. Although the difference in species abundance reflects those observed in the NW Pacific, no phylogeographic pattern was revealed. In addition, no population structure was observed whatever the species or the distribution range considered, which indicates a significant level of gene flow that maintains genetic homogeneity of the three species. It is also conceivable that each species experienced a recent population expansion from a single ancestral population. Finally we suggest that if the cold waters of the NW Pacific present a physiologic challenge leading to the almost parapatric distribution of the three species, then it is likely that the warm surface temperatures of the South China Sea negate this barrier.

Comparative genome size estimation of different life stages of grey mullet, Mugil cephalus Linnaeus, 1758 by flow cytometry

“…In this study, a 602 bp‐long fragment of the COI gene was used to identify the species which forms clusters based on the regional distribution of the species. The sample used in the present study clustered with the other Indian accessions, Bangladesh, Fiji and Vietnam and similar clustering having regional distribution pattern was previously reported (Durand et al, 2012, 2017; Viet Tran et al, 2017; Whitfield et al, 2012), which helps confirming the identity of the species. Though the phylogenetic tree indicated clearly about the species identity of the Indian specimen, its proximity towards Bangladesh and other Indian specimens is supported by a lower bootstrap value (56%).…”

“…Mugil curema (0.69 pg or 0.675 Gb; Mirsky & Ris, 1951), Liza ramada with the other Indian accessions, Bangladesh, Fiji and Vietnam and similar clustering having regional distribution pattern was previously reported (Durand et al, 2012(Durand et al, , 2017Viet Tran et al, 2017;Whitfield et al, 2012), which helps confirming the identity of the species.…”

“…cephalus species complex revealed that even though M . cephalus are allopatric with distinct regional distribution patterns, three mitochondrial lineages occur sympatrically in Taiwan (Durand et al, 2017) and Vietnam (Viet Tran et al, 2017). The distributional range within the M .…”

DNA barcoding of coastal ray-finned fishes in Vietnam

“…DNA barcoding would be a powerful tool to improve the knowledge of fish fauna in Vietnam. However, there have been only a few DNA barcoding studies of fishes in Vietnam and most of them were focused on a small taxonomic scale and/or samples collected from a limited area [37–40]. A comprehensive DNA barcoding study on the coastal fishes of Vietnam is urgently needed, especially before its’ growing fishery industry threatening the diversity.…”

DNA Barcoding of Mullets (Family Mugilidae) from Pakistan Reveals Surprisingly High Number of Unknown Candidate Species

“…Within the Mugil cephalus species complex, these new MOTUs presents significant phylogenetic relationships with Mugil sp. L (BOLD:AAA7893) (Figure 4B) observed in the Pacific Ocean [2,18,64]. Mugil cephalus is considered as a species complex consisting of 15 candidate species including Mugil liza in the West Atlantic [2,18].…”