Insights into historical drainage evolution based on the phylogeography of the chevron snakehead fish (Channa striata) in the Mekong Basin

Abstract

Summary 1. The phylogeography of freshwater taxa is often integrally linked with landscape changes such as drainage re‐alignments that may present the only avenue for historical dispersal for these taxa. Classical models of gene flow do not account for landscape changes and so are of little use in predicting phylogeography in geologically young freshwater landscapes. When the history of drainage formation is unknown, phylogeographical predictions can be based on current freshwater landscape structure, proposed historical drainage geomorphology, or from phylogeographical patterns of co‐distributed taxa. 2. This study describes the population structure of a sedentary freshwater fish, the chevron snakehead (Channa striata), across two river drainages on the Indochinese Peninsula. The phylogeographical pattern recovered for C. striata was tested against seven hypotheses based on contemporary landscape structure, proposed history and phylogeographical patterns of co‐distributed taxa. 3. Consistent with the species ecology, analysis of mitochondrial and microsatellite loci revealed very high differentiation among all sampled sites. A strong signature of historical population subdivision was also revealed within the contemporary Mekong River Basin (MRB). Of the seven phylogeographical hypotheses tested, patterns of co‐distributed taxa proved to be the most adequate for describing the phylogeography of C. striata. 4. Results shed new light on SE Asian drainage evolution, indicating that the Middle MRB probably evolved via amalgamation of at least three historically independent drainage sections and in particular that the Mekong River section centred around the northern Khorat Plateau in NE Thailand was probably isolated from the greater Mekong for an extensive period of evolutionary time. In contrast, C. striata populations in the Lower MRB do not show a phylogeographical signature of evolution in historically isolated drainage lines, suggesting drainage amalgamation has been less important for river landscape formation in this region.

Genotyping of microsatellite markers to study genetic structure of the wild striped snakehead Channa striata in Malaysia

“…The relatively high populations pairwise comparisons F ST and R ST are similar to those in C. striata populations of Mekong (Adamson et al , ) and other freshwater fishes such as the marble trout Salmo marmoratus Cuvier 1829 (Fumagalli et al , ), the three‐spined stickleback Gasterosteus aculeatus L. 1758 (Caldera & Bolnick, ) and the grass carp Ctenopharyngodon idella (Valenciennes 1844) (Liu et al , ). Chauhan et al () postulated that low population structuring in several riverine species, such as the Indian major carp Cirrhinus mrigala (Hamilton 1822), resulted from common ancestry and gene transfer between different river basins.…”

“…Previous reports on the population genetics of C. striata , from the Peninsular Malaysia used the random amplified polymorphic DNA method (Ambak et al , ), from the Mekong River used both mitochondrial DNA and nuclear microsatellite markers (Adamson et al , ) and from Sundaland used mitochondrial DNA markers (Tan et al , ). There is significant genetic differentiation among the surveyed populations and a vast genetic differentiation among fish from various sampling sites (Adamson et al , ; Tan et al , ). High genetic fragmentation is expected for C. striata , being restricted by waterways as the only dispersal channel for this obligate and relatively non‐migratory freshwater fish (Halls et al , ).…”

Genetic structure and diversity of migratory freshwater fish in a fragmented Neotropical river system

“…In different river basins, low levels of population genetic differentiation have been reported for other species that, like P. lineatus, also exhibit high migration capabilities ([1000 km) Lopes et al 2007;Santos et al 2007;Ribolli et al 2012;Berdugo and Barandica 2014). Migratory movements help maintain high gene flow, which in turn results in less pronounced population structure (Freeland 2005;Adamson et al 2012). However, other aspects intrinsic to the biology of P. lineatus, such as migratory behaviors and broadcast spawning habits, should also be taken into account.…”

“…Dispersal potential and significant migration rates are essential for maintaining species' genetic variability (Freeland 2005;Adamson et al 2012). Migratory fish populations, including several species of Neotropical freshwater fish, have been reported to exhibit high levels of genetic diversity (Matsumoto and Hilsdorf 2009;Santos et al 2007;Rueda et al 2011;Berdugo and Barandica 2014).…”

Plio-Pleistocene phylogeography of the Southeast Asian Blue Panchax killifish, Aplocheilus panchax

“…Our study adds to the mounting body of evidence [15,18,21,68–73] indicating that freshwater diversity within SE Asia is currently underestimated, and is in urgent need of further research and conservation effort.…”