Cryptic species diversity and molecular diagnosis of ; an endemic freshwater fish of Sri Lanka.

Fish genetic resources and diversity are very important aspects of environmental management and fisheries and are vital for making decisions on their commercial exploitation as well as conservation. The snakehead fishes in the world have significant economic importance as food and ornamental fish. A clear understanding of species' taxonomic status and genetic diversity is important for the utilization and implementation of conservation and management practices. is a snakehead endemic to Sri Lanka that is heavily utilized in the ornamental fish export trade. Its genetic diversity has not yet been fully understood and it is difficult to distinguish it from closely resembling species. Therefore, we examined the genetic diversity of and developed a DNA-based marker that permits accurate, low cost, and reliable identification of . Determination of genetic diversity was mainly carried out through genetic analysis of the mitochondrial () gene. The development of the DNA-based marker for the identification of was done through Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) analysis. Our analyses confirmed the presence of two distinct genetically divergent and geographically separated lineages of in Sri Lanka. The fast cost-effective gel-based PCR-RFLP marker method developed by us was successful in diagnosing from its closely resembling species. Thus, we believe our findings on the cryptic diversity and diagnostic methods will have important implications for the conservation and management of this endemic species.