Snakehead fishes of the family Channidae are obligatory air-breathers freshwater predators, the vast majority of which belong to the genus Channa Scopoli, 1777. Channa species are characterized by high karyotypic diversity due to various types of chromosomal rearrangements. It is assumed that, in addition to the lifestyle, fragmentation and isolation of snakehead populations contribute to an increase in karyotypic diversity. However, the chromosome complements of many isolated populations of widespread Channa species remain unknown, and the direction of karyotype transformations is poorly understood. This paper describes the previously unstudied karyotypes of Channa lucius (Cuvier, 1831) and C. striata (Bloch, 1793) from Phu Quoc Island and analyzes the trends of karyotypic evolution in the genus Channa. In C. lucius, the karyotypes are differed in the number of chromosome arms (2n = 48, NF = 50 and 51), while in C. striata, the karyotypes are differed in the diploid chromosome number (2n = 44 and 43, NF = 48). A comparative cytogenetic analysis showed that the main trend of karyotypic evolution of Channa species is associated with a decrease in the number of chromosomes and an increase in the number of chromosome arms, mainly due to fusions and pericentric inversions. The data obtained support the assumption that fragmentation and isolation of populations, especially of continental islands, contribute to the karyotypic diversification of snakeheads and are of interest for further cytogenetic studies of Channidae.

中文翻译：

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富国岛鳢和鳢的染色体补充以及黑鱼（Actinopterygii，鳢科）的核型进化

 鳢科的黑鱼是必须呼吸空气的淡水捕食者，其中绝大多数属于鳢属，1777。由于各种类型的染色体重排，鳢物种具有高度核型多样性的特点。据推测，除了生活方式之外，蛇头种群的分裂和隔离也有助于核型多样性的增加。然而，广泛分布的鳢属物种的许多分离种群的染色体互补体仍然未知，并且对核型转变的方向知之甚少。本文描述了以前未研究过的来自富国岛的Channa lucius (Cuvier, 1831) 和C. striata (Bloch, 1793) 的核型，并分析了Channa 属的核型进化趋势。在 C. lucius 中，核型的差异在于染色体臂的数量（2n = 48，NF = 50 和 51），而在 C. striata 中，核型的差异在于二倍体染色体数量（2n = 44 和 43，NF） = 48）。比较细胞遗传学分析表明，鳢属物种核型进化的主要趋势是染色体数量减少和染色体臂数量增加，主要是由于融合和着丝粒倒位。获得的数据支持这样的假设，即种群的破碎和隔离，尤其是大陆岛屿的种群的破碎和隔离，有助于黑鱼的核型多样化，并且对鳢科的进一步细胞遗传学研究具有重要意义。