Killifishes are a unique and diversified fish group composed of several annual species inhabiting ephemeral pools in tropical and subtropical regions. Moreover, many genera have probably undergone fast speciation with a high number of short-ranged species of controversial taxonomy. This is the case of the "Hypsolebias flavicaudatus" complex (Aplocheiloidei, Rivulidae) that includes nine recently described taxa of remarkable morphological similarity, endemic to Brazil. Considering the potential of cytotaxonomy of killifishes, as presently revised, we performed cytogenetic analyses in two sister species within this complex (H. flagellatus and H. janaubensis), including the first mapping of ribosomal genes in Hypsolebias. Despite sharing 48 chromosomes and similar distribution of heterochromatin and 5S rDNA, their karyotype formula probably differed as a result of pericentric inversions. In addition, H. flagellatus presented a single pair bearing 18S rDNA and GC-rich regions, while multiple GC-rich and 18S signals (up to 28 chromosomes) were detected in H. janaubensis. These results reinforce the dynamism of karyotype evolution in annual killifishes favored by population isolation and small effective size. Thus, cytogenetic variation seems to be closely associated with speciation in Aplocheiloidei, representing a useful tool for identifying similar species in Hypsolebias complex, which are vulnerable to extinction.

中文翻译：

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染色体标记可用于鉴定蛇形病毒科（Cyprinodontiformes，Aplocheiloidei）的物种，包括解决脆弱物种群中的分类学不确定性。

illi鱼是一种独特而多样化的鱼群，由居住在热带和亚热带地区的短暂池中的几种一年生物种组成。此外，许多属可能已经经历了快速的物种形成，并引起了许多有争议的分类学的近距离物种。这就是“ Hypsolebias flavicaudatus”复合体（Aplocheiloidei，Rivulidae）的情况，其中包括九个最近描述的具有明显形态相似性的类群，是巴西特有的。考虑到目前进行修订的杀死鱼类的细胞分类学的潜力，我们在该复合体中的两个姊妹物种（H.鞭毛虫和H.janaubensis）中进行了细胞遗传学分析，包括首次在南极茄中绘制了核糖体基因。尽管共有48条染色体，并且异染色质和5S rDNA分布相似，他们的核型公式可能是由于周向反转所致。此外，鞭毛嗜血杆菌呈现出一对带有18S rDNA和GC富集区域的单对，而在詹纳伯梭菌中检测到多个GC富集和18S信号（最多28条染色体）。这些结果加强了种群分离和有效个体小有利于一年生鱼类的核型进化的动力。因此，细胞遗传学变异似乎与Aplocheiloidei中的物种形成密切相关，代表了一种有用的工具，可用于识别蛇毒多形体中容易灭绝的相似物种。这些结果加强了种群分离和有效个体小有利于一年生鱼类的核型进化的动力。因此，细胞遗传学变异似乎与Aplocheiloidei中的物种形成密切相关，代表了一种有用的工具，可用于识别蛇毒多形体中容易灭绝的相似物种。这些结果加强了种群分离和有效个体小有利于一年生鱼类的核型进化的动力。因此，细胞遗传学变异似乎与Aplocheiloidei中的物种形成密切相关，代表了一种有用的工具，可用于识别蛇毒多形体中容易灭绝的相似物种。