Wertheimerinae is a small subfamily of thorny catfish composed of two species found in eastern Brazilian coastal drainages: Wertheimeria maculata and Kalyptodoras bahiensis. According to molecular phylogenetic analysis, Franciscodoras marmoratus an endemic species of the São Francisco River is also a member of this subfamily. Even though both phylogenetic approaches suggest that this group is one of the oldest lineages of the Doradidae, a disagreement remains about the constitution of Wertheimerinae. Hence, cytogenetic analysis is important to understand the karyotypic evolution of thorny catfish and can be a useful cytotaxonomic tool to clarify the relationships between these species. All Wertheimerinae species, and F. marmoratus here analyzed, shared 2n = 58 chromosomes, karyotypic formulas (24m+12sm +8st +14a), and nucleolus organizer region (NOR) pattern (terminal 18S rDNA sites on pair 22). Differences were noted in heterochromatin and 5S rDNA site distribution. The chromosomal markers here applied added to the molecular data, reinforcing that these three species actually represent a well-resolved taxonomic unit. Our results represent one more evidence of the ancient connectivity between eastern coastal drainages and São Francisco River, whose separation represented an important event for the allopatric speciation that produced the current forms of Wertheimerinae subfamily.

中文翻译：

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棘手Cat鱼的染色体多样性（Siluriformes-Doradidae）：圣弗朗西斯科州Wertheimerinae物种和巴西东部沿海排水系统中的异源物种。

Wertheimerinae是棘手cat鱼的一个小亚科，由在巴西东部沿海流域中发现的两个物种组成：Wertheimeria maculata和Kalyptodoras bahiensis。根据分子系统发育分析，圣弗朗西斯科河的特有物种Franciscodoras marmoratus也是该亚科的成员。即使两种系统发育方法都表明该群体是十二指肠最古老的血统之一，但关于Wertheimerinae的构成仍存在分歧。因此，细胞遗传学分析对于理解棘手cat鱼的核型进化很重要，并且可以作为阐明这些物种之间关系的有用的细胞分类学工具。所有Wertheimerinae物种和此处分析的F. marmoratus共有2n = 58条染色体，核型公式（24m + 12sm + 8st + 14a），和核仁组织区（NOR）模式（对22的18S rDNA末端位点）。在异染色质和5S rDNA位点分布上注意到差异。此处应用的染色体标记添加到了分子数据中，从而增强了这三个种类实际上代表了一个已很好解析的分类单位。我们的结果再一次证明了东部沿海流域和圣弗朗西斯科河之间的古老联系，后者的分离代表了产生现今Wertheimerinae亚科的异源物种形成的重要事件。