Genetic Stock Structure of Terapon jarbua in Taiwanese Waters

Abstract

Over the past century, stock identification, which is crucial for fisheries stock assessments, has relied heavily on intraspecies variations to differentiate management units. In recent years, however, DNA approaches have shed additional light on some aspects of the natural history and ecology of species and stocks. The Crescent Grunter Terapon jarbua is widely distributed across the Indo-Pacific region. It inhabits coastal waters with sandy substrates and tends to aggregate in estuaries. In the present study, we collected 96 individuals of T. jarbua from 10 locations around the shoreline of Taiwan as well as near Guangdong, China. A concatenated sequence (1,753 bp) of mtDNA (cytochrome c oxidase I and cytochrome b) was obtained from all individuals. We discovered two genetically distinct clades (lineages A and B) with different historical demographies occurring sympatrically except at the Yilan collection site, which was dominated by lineage A haplotypes. Connectivity within this region is high according to F ST and AMOVA tests. The genetic variation between the two clades is far below the interspecies threshold for the genus Terapon (0.007 versus 0.3156). Therefore, we suggest that they be considered different genetic stocks from a fisheries management point of view and that future stock reassessment should be conducted based on the genetic information provided in this study. Further large-scale sampling is needed to understand the mechanisms that drive genetic partitioning on regional (Northwest Pacific) and global (Indo-Pacific) scales.

Genetic diversity and population structure of Terapon jarbua (Forskål, 1775) (Teleostei, Terapontidae) in Malaysian waters

“…The inference of population expansion is further supported by the star-like patterns in Figure 3. Our results agree with an earlier study of T. jarbua populations from the Taiwanese waters which exhibited similarly high population haplotype diversity ranging from 0.86 to 1.00 as inferred from COI and Cyt b sequence data (Liu et al 2015). In a study on T. jarbua populations from the Gulf of Aden, Lavergne et al (2014) reported similarly high genetic diversities ranging from 0.216 to 0.698.…”

“…Polymerase Chain Reaction (PCR) amplification of approximately 1000 bp from the 5'end of the Cyt b gene was performed using the primer pairs Glu31 and Thr33 (Liu et al 2015) and internal primers: Glu231 (5'-CTT ACA GGC CTC TTT CTG GCC AT-3') and Thr233 (5'-TTT GAG CTA CTA ATG CAG TAT-3') were designed for this study.…”

“…In general, a relatively high haplotype diversity (0.92-0.99) and low nucleotide diversity (0.03-0.34) were observed for the populations in this study. The combination of high haplotype diversity and low nucleotide diversity is common in pelagic marine fishes (Liu et al 2015). This is likely due to rapid demographic expansion from a small effective population size, assuming there is sufficient time for the number of haplotypes to increase through mutation but insufficient for accumulation of large sequence differences (Grant and Bowen 1998;Avise 2000;Lowe et al 2004).…”

“…Southeast Asia is believed to have experienced simultaneous glaciation and consequent deglaciation along with its associated decrease and increase of seawater levels during the Pleistocene period, which greatly influenced continental and oceanic configuration (Voris 2000). The shared haplotypes between Malaysian populations and those from as far as India suggests that the range of population expansion after glacial retreat was not restricted to the South China Sea but also extended into the Indian Ocean (Liu et al 2015). Lavergne et al (2014) also reported high connectivity between populations in the Gulf of Aden and South China Sea due to the unique sharing of COI haplotypes between both regions.…”

“…Existing reports on T. jarbua are generally limited to their morphometry (e.g., length-weight relationship) and reproductive biology (Miu et al 1990;Nandikeswari et al 2014;Musarrat and Masood 2015) while the information on their genetic diversity and population structures is relatively little. Lavergne et al (2012) and Liu et al (2015) reported on the population genetic diversity of T. jarbua in the Gulf of Aden, Yemen and Taiwanese waters, respectively, using cytochrome c oxidase subunit I (COI), cytochrome b (Cyt b) and microsatellites molecular markers. Also, a phylogeo-graphic survey of T. jarbua along with other reef fauna of the western Indian Ocean was reported by Borsa et al (2016) using COI gene sequences.…”