Abstract

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. Channa orientalis 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 C. orientalis and developed a DNA-based marker that permits accurate, low cost, and reliable identification of C. orientalis. Determination of genetic diversity was mainly carried out through genetic analysis of the mitochondrial cytochrome c oxidase subunit 1 (MT-CO1) gene. The development of the DNA-based marker for the identification of C. orientalis 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 C. orientalis in Sri Lanka. The fast cost-effective gel-based PCR-RFLP marker method developed by us was successful in diagnosing C. orientalis 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.

摘要

鱼类遗传资源和多样性是环境管理和渔业非常重要的方面，对于商业开发和保护的决策至关重要。世界上的蛇头鱼作为食用鱼和观赏鱼具有重要的经济意义。清楚地了解物种的分类地位和遗传多样性对于保护和管理实践的利用和实施非常重要。Channa orientalis是斯里兰卡特有的一种蛇头，在观赏鱼出口贸易中大量使用。它的遗传多样性尚未完全了解，很难将其与非常相似的物种区分开来。因此，我们检查了C. orientalis的遗传多样性并开发了一种基于 DNA 的标记物，可以准确、低成本和可靠地鉴定C. orientalis。遗传多样性的测定主要通过线粒体细胞色素c氧化酶亚基1（MT-CO1）基因的遗传分析来进行。通过聚合酶链式反应和限制性片段长度多态性 (PCR-RFLP) 分析开发了基于 DNA 的用于识别东方蠓的标记。我们的分析证实了斯里兰卡存在两种不同的遗传差异和地理上分离的C. orientalis谱系。我们开发的快速、高性价比的基于凝胶的PCR-RFLP标记方法诊断成功C. orientalis来自其非常相似的物种。因此，我们相信我们对神秘多样性和诊断方法的发现将对这一特有物种的保护和管理产生重要影响。