Population genetic structure of Asian snakehead fish (Channa striata) in North Borneo: Implications for conservation of local freshwater biodiversity

Abstract

This study quantified the intra‐specific diversity and characterized the population structure of the Asian snakehead fish, Channa striata in Sabah, North Borneo by determining the variability at six microsatellite loci. Range of genetic diversity across all sampled populations was comparatively moderate in relation to levels reported for C. striata populations occurring elsewhere and the overall Sabah population is highly structured, reflecting isolations across geological and ecological time scales. Two reciprocally monophyletic genodemes were identified along the west and east coast that may have been separated by mountain upthrusts throughout the central region of Sabah. Despite kinship among populations within each genodeme, individual demes were discrete as indicated by significant genotypic differentiation (all P < 0.0014) and low estimates of gene flow between them that likely reflect natural fragmentation of freshwater habitats they occupy. Our findings underline the potential of molecular markers in delimiting and delineating geospatial units of conservation in Sabah. Lowland freshwater ecosystems in the area may comprise two geographically isolated ecoregions, in which each hypothetically harbours biota that have evolved allopatrically. Additionally, identification of biodiversity hotspots within these putative ecoregions can be greatly facilitated with genetic‐level investigations as the rate by which freshwater communities are inventoried has been extremely slow in most habitats.

Phylogeographic Structure of Freshwater Tor sp. in River Basins of Sabah, Malaysia

“…This finding supports the studies of other taxa that proposed the mountain ranges in Sabah play a role in the maintenance of ancient lineages and species diversity [69,70]. In this study, Labuk River appeared to have potentially retained large proportions of ancestral genotypes as shown by its location in the basal position of the phylogeographic tree, the same results obtained for Channa striata [13]. This shows Sandakan is the origin of colonization before the expansion of populations to eastern clades.…”

“…The clustering coincides with the separation of Sabah in the center by CTR and in accordance with major river systems. The results of this study were also obtained by the authors of [13], where Channa striata is subdivided into two genodeme, namely Genodeme 1 and Genodeme 2, which were known in this study as western and eastern clusters, respectively.…”

“…Delineating CUs among the freshwater biodiversity of Sabah may go a long way in strategizing efforts to protect habitats and threatened species. A previous study [13] identified two reciprocally monophyletic genodemes of Channa striata along the western and eastern coasts of Sabah, Malaysian Borneo, which corresponded to two ESUs comprising historically separated subpopulations with allopatrically evolving microsatellite alleles. Further, there was a lack of migration between adjacent river systems, and several drainages appeared to have formed internal clades with suitable bootstrapping support (i.e., percent bootstrap > 70%; [14]), suggesting the presence of MUs within each genome.…”

“…To fill this gap in information, we carried out a study to further identify other ESU/ESUs pertaining to the inland freshwater ecosystem of Sabah with respect to the phylogeography of Tor sp. We hypothesized that the central highland freshwater habitats of Sabah harbor at least one genetically isolated ESU that is distinct from the coastal ESUs in the work of [13]. Identification of MUs will also be carried out concurrently to assist in the management of freshwater biological resources in the state.…”

Short Communication: DNA barcodes and phylogenetic of striped snakehead and ocellated snakehead fish from South Sumatra, Indonesia

“…However, those species also make a different sub-clusters within species, for instance, sample of this study were in different sub-clusters from Indonesia (West and Central Kalimantan), USA (bv=96) and also another sub-clusters of Vietnam, China, the Philippines, Brunei Darussalam, Thailand, and Malaysia (bv=89). Robert et al (2018) reported there were two reciprocally monophyletic genomes of C. striata were identified along the west and east coast that may have been separated by mountain upthrusts throughout the central region of Sabah, Malaysia.…”