2018/12/20 by Hiranya Sudasinghe, Jayampathi Herath, Rohan Pethiyagoda +1 · 2 citations
Agricultural and Biological Sciences · Environmental Science · Biochemistry, Genetics and Molecular Biology · #Fish Biology and Ecology Studies #Fish Ecology and Management Studies #Genetic diversity and population structure
paper · doi:10.7717/peerj.6084
openalex publication_date 2018/12/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/14
A recent (2013) taxonomic review of the freshwater-fish genus Rasboroides , which is endemic to Sri Lanka, showed it to comprise four species: R. vaterifloris , R. nigromarginatus , R. pallidus and R. rohani. Here, using an integrative-taxonomic analysis of morphometry, meristics and mitochondrial DNA sequences of cytochrome b ( cytb ) and cytochrome oxidase subunit 1 ( coi ), we show that R. nigromarginatus is a synonym of R. vaterifloris , and that R. rohani is a synonym of R. pallidus. The creation and recognition of unnecessary taxa (‘taxonomic inflation’) was in this case a result of selective sampling confounded by a disregard of allometry. The population referred to R. rohani in the Walawe river basin represents an undocumented trans-basin translocation of R. pallidus , and a translocation into the Mahaweli river of R. vaterifloris , documented to have occurred ca 1980, in fact involves R. pallidus. A shared haplotype suggests the latter introduction was likely made from the Bentara river basin and not from the Kelani, as claimed. To stabilize the taxonomy of these fishes, the two valid species, R. vaterifloris and R. pallidus , are diagnosed and redescribed, and their distributions delineated. We draw attention to the wasteful diversion of conservation resources to populations resulting from undocumented translocations and to taxa resulting from taxonomic inflation. We argue against translocations except where mandated by a conservation emergency, and even then, only when supported by accurate documentation.