Background

The genus Nematostrigea comprises trematodes parasitising in fish-eating birds of Europe, Africa, and North America. Their life cycle is unknown.

Purpose

To provide the first description of metacercariae of Nematostrigea serpens serpens, a nominative subspecies of the type species of Nematostrigea, and to record metacercaria of Nematostrigea vietnamiensis, with molecular data.

Methods

Encysted metacercariae of N. serpens serpens and N. vietnamiensis were collected from fish in Russia and Vietnam, respectively, and were processed, identified, and documented using standard morphological techniques. The 28S rRNA gene of metacercariae of both species and the cox1 gene of metacercariae an earlier studied adult of N. serpens serpens were sequenced and used for phylogenetic analysis.

Results

Metacercaria of N. serpens serpens have a spatulate body with a foliate forebody and a short hindbody, two long lateral rectilinear pseudosuckers, and the holdfast organ with bifurcated anterior and entire posterior external lobes. The analysis of the cox1and 28S rRNA gene sequences unequivocally showed the conspecificity of metacercariae and adult stage of N. serpens serpens. Based on the 28S rRNA gene sequence-based phylogenetic analysis, the genus Nematostrigea is a sister taxon to the group of strigeid genera Cotylurus + Ichthyocotylurus. Morphological and phylogenetic data demonstrated that N. vietnamiensis does not belong to the genus Nematostrigea and is possibly be affiliated with the crassiphialine trematodes.

Conclusion

This is the first record of metacercariae of N. serpens serpens. N. vietnamiensis, renamed Prodiplostomulum vietnamiense comb. nov., must be moved to the crassiphialine ‘Prodiplostomulum’-type metacercariae group

中文翻译：

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对 Nematostrigea serpens serpens (Nitzsch, 1819) (Trematoda, Strigeidae) 和 Nematostrigea vietnamiensis Zhokhov & Mishina 的系统发育隶属关系的首次描述，2011。

背景

属Nematostrigea包括吸虫在欧洲，非洲和北美的食鱼鸟类parasitising。它们的生命周期未知。

目的

为了提供囊蚴的第一描述Nematostrigea巨蛇巨蛇的类型，物种的主格亚种Nematostrigea，并记录囊蚴Nematostrigea vietnamiensis，随着分子数据。

方法

分别从俄罗斯和越南的鱼类中收集了N. serpens serpens和N. vietnamiensis 的包囊囊蚴，并使用标准形态学技术进行处理、鉴定和记录。对两种物种的囊蚴的28S rRNA基因和早期研究的N. serpens serpens成虫的囊蚴的cox1基因进行测序并用于系统发育分析。

结果

N. serpens serpens 的Metacercaria有一个带叶状前体和一个短后体的匙状体，两个长的横向直线假吸盘，以及具有分叉的前部和整个后部外叶的固定器官。所述的分析COX1和28S rRNA的基因序列明确地表明囊蚴和成虫阶段的conspecificity N.巨蛇巨蛇。基于所述28S rRNA的基于序列的基因系统发育分析，属Nematostrigea是姊妹类群到组strigeid属的Cotylurus  +  Ichthyocotylurus。形态学和系统发育数据表明，越南猪笼草不属于Nematostrigea属，可能隶属于 crassiphialine 吸虫。

结论

这是对N. serpens serpens囊蚴的首次记录。N. vietnamiensis，更名为Prodiplostomulum vietnamiense comb。11 月，必须移至 crassiphialine ' Prodiplostomulum ' -型囊蚴群