Boni T A, Padial A A, Prioli S M A P, Lucio L C, Maniglia T C, Bignotto T S, Panarari-Antunes R S, Prioli R A, Prioli A J
Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura, Universidade Estadual de Maringá, Maringá, PR, Brasil.
Genet Mol Res. 2011 Nov 10;10(4):2795-805. doi: 10.4238/2011.November.10.2.
Fish species of the Zungaro genus (Siluriformes, Pimelodidae) are amongst the largest migratory fish in Latin America and have considerable economic importance for commercial fishing in Brazil. However, natural populations of this large catfish are experiencing a severe decline. There are significant taxonomical inconsistencies for this fish. Two geographically separated species of the fish were initially described, one endemic in the Amazon and another in the Paraná-Paraguay River basins. A taxonomic review had recently proposed that there is only one Zungaro species in Brazil, based on morphological data. We made a molecular study of Zungaro populations in an attempt to solve taxonomical inconsistencies and to analyze genetic diversity in natural populations of this genus. We analyzed two regions of the mitochondrial DNA (the control region and the ATPase 6 gene region) of individuals sampled from the Paraná-Paraguay River and Amazon River basins. Analyses based on p-distances and maximum likelihood phylogenetic models showed a genetic difference between populations corresponding to different species. Genetic differentiation between Zungaro populations was at the same level as that observed between other Siluriformes species, using the same DNA sequences. We conclude that Zungaro species of the Paraná-Paraguay River basin do not belong to the same species found in the Amazon basin. This finding has a significant implication for conservation of this fish, given that populations are disappearing at a high rate in the Paraná-Paraguay River basin, mainly due to impoundments.
宗加罗属鱼类（鲇形目，油鲇科）是拉丁美洲最大的洄游鱼类之一，对巴西的商业捕鱼具有相当重要的经济意义。然而，这种大型鲶鱼的自然种群正在急剧减少。这种鱼在分类学上存在重大不一致之处。最初描述了该鱼的两个地理隔离物种，一个是亚马逊河特有的，另一个是巴拉那 - 巴拉圭河流域特有的。最近一项分类学综述基于形态学数据提出，巴西只有一种宗加罗属鱼类。我们对宗加罗种群进行了分子研究，试图解决分类学上的不一致问题，并分析该属自然种群的遗传多样性。我们分析了从巴拉那 - 巴拉圭河和亚马逊河流域采集的个体的线粒体DNA的两个区域（控制区和ATP酶6基因区域）。基于p距离和最大似然系统发育模型的分析表明，对应于不同物种的种群之间存在遗传差异。使用相同的DNA序列，宗加罗种群之间的遗传分化与在其他鲇形目物种中观察到的遗传分化处于同一水平。我们得出结论，巴拉那 - 巴拉圭河流域的宗加罗属鱼类与亚马逊河流域发现的鱼类不属于同一物种。鉴于巴拉那 - 巴拉圭河流域的种群正在以很高的速度消失，主要是由于筑坝，这一发现对这种鱼类的保护具有重大意义。
