Purpose

To describe three new species of Cosmetocleithrum in the gills of Trachelyopterus galeatus (Siluriformes, Auchenipteridae) from Aguapeí River, Upper Paraná River basin, São Paulo State, Brazil.

Methods

Fifty-three specimens of T. galeatus were captured in the mouth of the Aguapeí River from August 2013 to June 2014. Monogeneans were mounted unstained in Hoyer’s and Gray and Wess’s medium.

Results

Cosmetocleithrum spathulatum sp. n., Cosmetocleithrum baculum sp. n., and Cosmetocleithrum galeatum sp. n. differ from all known congeneric species mainly in the morphology of the accessory piece (i.e. spatulate-shaped, claviform, and a straight rod with hook-shaped distal portion, respectively). Also, the three new species share hooks with different sizes with hooks pairs 5 and 7 bigger than others and with an erect delicate point, inconspicuous thumb, longer shaft, and slender shank.

Conclusions

To date, 18 species of Cosmetocleithrum were recognised parasitizing siluriforms in the Neotropical region. The present study expands the number to 21 species, however, despite this increase, the number of known taxa of monogeneans in neotropics is far from representing the ideal situation.

中文翻译：

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巴西东南部草蛉科（Siluriformes：Auchenipteridae）鳃寄生虫的三个新种（单系：Dactylogyridae）

目的

描述巴西圣保罗州巴拉那河上游流域阿瓜佩伊河（Aguapeí River，Siluriformes galeatus，Auchenipteridae）的鳃中的三个新种Cosmetocleithrum。

方法

从 2013 年 8 月到 2014 年 6 月，在阿瓜佩河河口捕获了53 个T. galeatus标本。 Monogeneans 在 Hoyer 和 Gray and Wess 培养基中未染色。

结果

Cosmetocleithrum spathulatum sp. n., Cosmetocleithrum baculum sp. n. 和Cosmetocleithrum galeatum sp。n. 与所有已知的同类物种的主要区别在于附件的形态（即分别为铲状、棒状和带有钩状远端部分的直杆）。此外，这三个新物种共享不同大小的钩子，钩子比其他的大5和7，并具有直立的精致尖端，不显眼的拇指，更长的轴和细长的柄。

结论

迄今为止，已发现 18 种Cosmetocleithrum寄生于新热带地区的 siluriforms。目前的研究将数量扩大到 21 种，然而，尽管增加了，但新热带地区已知的单殖吸虫类群的数量远非理想情况。