First Evidence of Cryptic Species Diversity and Population Structuring of Selaroides leptolepis in the Tropical Western Pacific

Abstract

The yellowstripe scad, Selaroides leptolepis (Carangidae), is an important fish commodity in the Tropical Western Pacific (TWP). It has a latitudinal Pacific range from south of Japan down to northern Australia, with the highest concentration in Southeast Asia. However, its TWP fishing grounds have long been a hotspot of unsustainable exploitations, thus threatening the remaining wild populations. Despite the species’ commercial significance, there is limited understanding of its genetic structure and diversity. Herein, the genetic structure of S. leptolepis was examined using mitochondrial COI and CytB sequences. Both markers denoted significant genetic structuring based on high overall FST values. Hierarchical analysis of molecular variance (AMOVA), maximum likelihood (ML) phylogenetic trees, and median-joining (MJ) haplotype networks strongly supported the occurrence of two allopatrically distributed lineages. These comprised of a widespread Asian lineage and an isolated Australian lineage. Within-lineage distances were low (K2P < 1%) whereas across-lineage distances were remarkably high (K2P > 6%), already comparable to that of interspecific carangid divergences. Haplotype sequence memberships, high genetic variations, and the geographic correlation suggested that the Australian lineage was a putative cryptic species. Historical demographic inferences also revealed that the species experienced rapid expansion commencing on the late Pleistocene, most likely during the end of the Last Glacial Maximum (∼20,000 years ago). The present study encouraged the application of lineage-specific management efforts, as the lineages are experiencing different evolutionary pressures. Overall, accurate knowledge of the species’ genetic distribution is fundamental in protecting its diversity and assuring stock sustainability.

Biometrik dan Kematangan Gonad Ikan Selar Kuning (Selaroides leptolepis Cuvier, 1833) Pada Perairan Muara Badak, Kalimantan Timur

“…Beberapa penelitian terkait spesies ini membahas tentang aspek biologi reproduksi (Tarigan et al, 2017;Sinaga et al, 2018;Mustofa & Setyobudiandi, 2019;Pasisingi et al, 2020), hubungan panjang-bobot dan faktor kondisi (Ibrahim et al, 2017;Clarito, 2021;Pasisingi et al, 2021), dinamika populasi (Tangke et al, 2018;Tangke et al, 2021) dan pola pertumbuhan (Supeni & Almohdar, 2017). Penelitian dalam skala laboratorium tentang pemisahan peptida dari hidrosilat protein ikan Selar (Putalan et al, 2020) dan keragaman populasi genetik (Halasan et al, 2021). Penelitian pada ikan Selar kuning telah dipublikasikan pada banyak aspek dan lokasi, tetapi penelitian yang membahas tentang biologi khususnya aspek biometrik dan kematangan gonad ikan Selar kuning dari Perairan Muara Badak belum pernah dilaporkan.…”

Phylogeography and population structure of Lagocephalus spadiceus (Richardson, 1845) (Tetraodontiformes, Tetraodontidae) in the South China Sea

“…Due to the relationship between the rate and time of evolution, effective information sites are different, and their resolving power is different. Therefore, concatenating COI and Cyt b markers can increase the number of effective genetic sites, resulting in more accurate and effective information compared to single gene analysis (Barrientos‐Villalobos & Schmitter‐Soto, 2019; Halasan et al., 2021).…”

Bungarus fasciatus venom from eastern and north-east India: venom variation and immune cross-reactivity with Indian polyvalent antivenoms

“…Aside from its taxonomical importance, recognition and ascertainment of independently evolving lineages is crucial for understanding the evolutionary processes affecting the origin of population structure and species diversification [1]. Because of the growing availability of genetic methods for species delineation [2], numerous studies have uncovered cryptic diversity within the widespread vertebrate species including in tropical and sub-tropical Asia; for instance, among fishes [3][4][5], amphibians [6][7][8], birds [9][10][11], and mammals [12][13][14].…”