Background

The original description of Pachysentis canicola Meyer, 1931 was based on an unknown number of specimens from an undetermined species of Canis in Brazil from the Berlin Museum. It has since been reported from other carnivores in South and North America. Our specimens from the maned wolf, Chrysocyon brachyurus (Illiger, 1815), in Texas, represent a new host record, and has shed more light on morphometric characteristics missing from the original description, and expanded the range of variations in characters that remained fixed since 1931 and that have been repeated in other taxonomic accounts. We have found additional specimens in striped skunk, Mephitis mephitis Schreber, also in Texas.

Methods

We have performed metal analysis on hooks using EDXA (energy dispersive X-ray analysis). Sequences for the 18S gene and ITS1-5.8-ITS2 region of rDNA were generated to molecularly characterize the species for the first time.

Results

Worms with a massive trunk and a globular proboscis with prominent dome-like apical organ and 12 irregular spiral rows of 4–5 hooks deeply embedded in cuticular folds each, totaling 48–60 hooks. We have included line drawings of the male and female reproductive systems, among other structures, also missing from the original and subsequent descriptions. We describe a new population of P. canicola from Texas and report on the metal analysis of its hooks using EDXA. We also assess the phylogenetic position of P. canicola supporting its independent status in the family Oligacanthorhynchidae, inferred from the two molecular markers.

Conclusions

This is the foremost molecular characterization of any species of Pachysentis and will provide significant insights and reference for future molecular study of species of Pachysentis, especially from this newly described Texas population.

中文翻译：

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Pachysentis canicola Meyer, 1931 (Acanthocephala: Oligacanthorhynchidae) 的重新描述和分子表征来自德克萨斯州的鬃狼 Chrysocyon brachyurus (Illiger, 1815)

背景

Pachysentis canicola Meyer，1931 年的最初描述是基于柏林博物馆中来自巴西一种未确定的犬种的未知数量的标本。此后，南美洲和北美洲的其他食肉动物也有报道。我们在德克萨斯州的鬃狼Chrysocyon brachyurus (Illiger, 1815)的标本代表了一项新的宿主记录，并且更清楚地揭示了原始描述中缺失的形态特征，并扩大了自那时以来一直固定的字符变化范围1931 年，并且在其他分类账户中重复出现。我们还在德克萨斯州的条纹臭鼬Mephitis mephitis Schreber 中发现了其他标本。

方法

我们使用 EDXA（能量色散 X 射线分析）对钩子进行了金属分析。生成了 rDNA的18S基因和ITS1-5.8-ITS2区域的序列，以首次从分子上表征该物种。

结果

蠕虫有一个巨大的躯干和一个球形长鼻，具有突出的圆顶状顶端器官和12个不规则的螺旋排，每排4-5个钩子深深嵌入表皮褶皱中，总共48-60个钩子。我们已经包括了男性和女性生殖系统的线条图，以及其他结构，在原始和后续描述中也缺失了。我们描述了来自德克萨斯州的一个新的P. canicola种群，并报告了使用 EDXA 对其钩子的金属分析。我们还评估了P. canicola的系统发育位置，支持其在 Oligacanthorhynchidae 家族中的独立地位，从两个分子标记推断。

结论

这是对任何种类的Pachysentis最重要的分子特征，将为未来对Pachysentis物种的分子研究提供重要的见解和参考，特别是来自这个新描述的德克萨斯种群。