Purpose

We describe two new Henneguya spp. (Myxobolidae) found parasitizing Cyphocharax modestus from Pardo river, Paraná river basin, municipality of Botucatu, São Paulo State, Brazil: Henneguya fastigata n. sp. from gill lamellae and Henneguya pardensis n. sp. from gill arches. We based the descriptions on myxospore morphology, histology, and small subunit ribosomal DNA sequences.

Methods

In this investigation, 50 specimens of Cyphocharax modestus were examined between July and December 2020 for myxozoan infections. Morphological characterization was based on the mature myxospores. The small subunit ribosomal DNA sequences were used for molecular and phylogenetic study.

Results

Phylogenetic analysis provided the evolutionary position of these new species with other myxobolids species. Myxospores of the two species had similar morphology and morphometrics, but differed in spore body width and length, and ssrDNA sequences differed by 7.2%. These data supported the diagnosis of the parasites as distinct and novel species. The phylogenetic analysis showed a well-supported subclade formed by species that parasitize curimatid fishes, with Henneguya gilbert as a sister species of Henneguya fastigata n. sp., and Henneguya pardensis n. sp. as a sister species of both species.

Conclusion

Our analysis was consistent with previous studies suggesting that orders and families of the hosts are strongly correlated with phylogenetic signals in the Myxobolidae. These are the first species of myxozoans described in the Pardo river.

中文翻译：

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使用形态学、组织学和分子分析描述感染 Curimatid 鱼的两种新型 Henneguya（刺胞动物：粘孢子虫）

目的

我们描述了两种新的Henneguya spp。（Myxobolidae）在巴西圣保罗州博图卡图市巴拉那河流域的 Pardo 河发现寄生于Cyphocharax modetus： Henneguya fastigata n。sp。来自鳃片和Henneguya pardensis n。sp。从鳃弓。我们基于粘孢子形态、组织学和小亚基核糖体 DNA 序列的描述。

方法

在本次调查中，在 2020 年 7 月至 2020 年 12 月期间，对 50 份Cyphocharax meadowus 标本进行了粘虫感染检查。形态特征基于成熟的粘孢子。小亚基核糖体 DNA 序列用于分子和系统发育研究。

结果

系统发育分析提供了这些新物种与其他粘液体物种的进化位置。两个种的粘孢子具有相似的形态和形态特征，但孢子体的宽度和长度不同，ssrDNA序列差异为7.2%。这些数据支持将寄生虫诊断为独特的新物种。系统发育分析显示，由寄生于curimatid鱼类的物种形成了一个得到良好支持的亚进化枝，Henneguya gilbert是Henneguya fastigata n.的姐妹物种。sp. 和Henneguya pardensis n. sp。作为两个物种的姐妹物种。

结论

我们的分析与先前的研究一致，表明宿主的目和科与粘虫科的系统发育信号密切相关。这些是在帕尔多河中描述的第一种粘虫。