Contrasting genetic and morphological differentiation among geographical lineages of a stenotopic miniature rasborine, Boraras maculatus, in Peninsular Malaysia
Document Type
Article
Publication Date
1-1-2024
Abstract
The variability in the stenotopic miniature rasborine Boraras maculatus (Cypriniformes: Danionidae: Rasborinae) across acidic-water habitats of Peninsular Malaysia (PM) was investigated using two molecular markers (the mitochondrial cytochrome c oxidase subunit I COI gene and the nuclear rhodopsin gene), as well as morphological evidence. Molecular phylogenetic analyses revealed differentiation among populations of B. maculatus in PM with the distinction of four allopatric lineages. Each of them was recognized as a putative species by automatic species delimitation methods. These lineages diverged from each other between 7.4 and 1.9 million years ago. A principal component analysis (PCA) was conducted to examine the multivariate variation in 11 morphometric measurements among three of these lineages. PCA results showed a significant overlap in morphological characteristics among these lineages. Additionally, a photograph-based machine learning approach failed to fully differentiate these lineages, suggesting limited morphological differentiation. B. maculatus represents a case of morphological stasis in a stenotopic miniature species. Strong habitat preference, coupled with long-term habitat fragmentation, may explain why each lineage of B. maculatus has a restricted distribution and did not disperse to other regions within and outside of PM, despite ample possibilities when the Sunda shelf was emerged and drained by large paleodrainages for most of the past 7 million years. The conservation status of B. maculatus and its peat swamp habitats are discussed, and it is concluded that peat swamps comprise several evolutionary units. Each of these units is considered a conservation unit and deserves appropriate protection. © 2023 Fisheries Society of the British Isles.
Keywords
Animals, Cypriniformes, DNA, Mitochondrial, Genetic Variation, Malaysia, Phylogeny, Phylogeography, Soil, Mitochondrial DNA, Animal, Cypriniformes, Genetic variation, Genetics, Malaysia, Phylogeny, Phylogeography, Soil
Divisions
InstituteofBiologicalSciences
Funders
School of Biological Sciences, Universiti Sains Malaysia - Ministry of Natural Resources, Environment and Climate Change, Malaysia (NRECC), under National Conservation Trust Fund for Natural Resources [Grant no. KeTSA(S)600-2/1/48/5]
Publication Title
Journal of Fish Biology
Volume
104
Issue
1
Publisher
Wiley