Genetic diversity and structure of circumtropical almaco jack, Seriola rivoliana: tool for conservation and management

Abstract

The almaco jack, Seriola rivoliana, is a circumtropical pelagic fish of importance both in commercial fisheries and in aquaculture. To understand levels of genetic diversity within and among populations in the wild, population genetic structure and the relative magnitude of migration were assessed using mtDNA sequence data and single nucleotide polymorphisms (SNPs) from individuals sampled from locations in the Pacific and Atlantic Oceans. A total of 25 variable sites of cytochrome c oxidase subunit 1 and 3678 neutral SNPs were recovered. Three genetic groups were identified, with both marker types distributed in different oceanic regions: Pacific‐1 in central Pacific, Pacific‐2 in eastern Pacific and Atlantic in western Atlantic. Nonetheless, the analysis of SNP identified a fourth population in the Pacific coast of Baja California Sur, Mexico (Pacific‐3), whereas that of mtDNA did not. This mito‐nuclear discordance is likely explained by a recently diverged Pacific‐3 population. In addition, two mtDNA haplogroups were found within the western Atlantic, likely indicating that the species came into the Atlantic from the Indian Ocean with historical gene flow from the eastern Pacific. Relative gene flow among ocean basins was low with rm < 0.2, whereas in the eastern Pacific it was asymmetric and higher from south to north (rm > 0.79). The results reflect the importance of assessing genetic structure and gene flow of natural populations for the purposes of sustainable management.

Responses of population structure and genomic diversity to climate change and fishing pressure in a pelagic fish

“…In this study, the results of adaptive genomic differentiation between the sampled patches of S. rivoliana showed higher values of F ST than those previously reported based solely on neutral markers (Mendoza‐Portillo et al, 2020). There are still several uncertainties around the detection of loci that are under selection that may influence disparate patterns between neutral and outlier loci.…”

“…It is therefore essential to define population units for their adequate future management, particularly where resources are shared between countries. Unfortunately, little is known about the broader genomic structure and diversity of S. rivoliana , but using a suite of neutral single‐nucleotide polymorphisms (SNPs), Mendoza‐Portillo et al (2020) identified three populations in the Pacific Ocean and found high levels of gene flow between them. These populations did not follow a pattern of isolation by distance, suggesting that environmental variability may be a driver of population divergence and could be responsible for genomic structuring.…”

Genomic assessment reveals signal of adaptive selection in populations of the Spotted rose snapper Lutjanus guttatus from the Tropical Eastern Pacific

“…This pattern has been recovered in populations of the blue-banded goby ( Lythrypnus gilberti ) distributed in the Galapagos Islands, where the oceanographic conditions have promoted an adaptive process ( Bernardi, 2022 ). Although the growing evidence that the use of markers generated by NGS help us characterize the genetic structure of marine species, there are still very few examples of studies using NGS in the TEP ( Mendoza-Portillo et al, 2020 ; Bernardi, 2022 ).…”

Comparing DNA yield from fish scales following different extraction protocols

“…Notably, adaptive potential is becoming increasingly important due to the rapidly appearing effects of human-induced climate uncertainty in addition to stochastic fluctuations of the environment 4 , 5 . Therefore, analysing levels of genetic diversity is considered to be integral in deciding which populations should be prioritised for protective action 2 , 6 , 7 .…”