Introduction

A new species of the nematode genus Parastrongyloides Morgan, 1928 was found in the caecum of six short-beaked echidnas Tachyglossus aculeatus (Shaw, 1792) collected from southwestern Australia between August 1964 and March 2020.

Methods

Specimens were prepared for microscopic examination as temporary wet mounts, measurements were made using an Olympus DP71 camera with cellSens standard software, figures were drawn using a drawing tube and light micrographs taken. DNA was extracted using a Qiagen blood and tissue kit, amplified targeting the COX1 gene region. Sequences obtained were analysed and edited using Geneious v.8.1 and aligned to existing sequences published in Genbank using MUSCLE.

Results

Parastrongyloides spratti n. sp. can be distinguished from all other species of Parastrongyloides in having the male caudal papillae arranged as a single median dome-shaped pre-cloacal papilla, three tiny pairs of ventral papillae immediately pre-cloacal, a tiny ventral pair of papillae post-cloacal and the female with four to five pairs of dorsoventral papillae immediately anterior to the vulva. A revised key to the species of Parastrongyloides found in Australia is given. Sequence analysis of the COX1 gene corroborated the species status of P. spratti.

Discussion

Morphological and molecular analyses support the status of P. spratti as a new species. Parastrongyloides may have an ancient origin in the Australian portion of Gondwanaland.

中文翻译：

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西澳大利亚短喙针鼹 Tachyglossus aculeatus 副圆线虫（Rhabditida：类圆线虫科）的形态学和分子特征

介绍

1928 年，在 1964 年 8 月至 2020 年 3 月期间从澳大利亚西南部采集的六只短喙针鼹 Tachyglossus aculeatus（Shaw，1792 年）的盲肠中发现了一种新的线虫属副圆线虫属摩根。

方法

制备标本用于显微镜检查作为临时湿法，使用带有 cellSens 标准软件的 Olympus DP71 相机进行测量，使用绘图管绘制图形并拍摄光学显微照片。使用 Qiagen 血液和组织试剂盒提取 DNA，针对 COX1 基因区域进行扩增。使用 Geneious v.8.1 分析和编辑获得的序列，并使用 MUSCLE 与 Genbank 中发布的现有序列进行比对。

结果

沙棘副圆线虫 sp。与所有其他类圆线虫属的区别在于其雄性尾乳头排列为单个正中圆顶状前泄殖腔乳头、三对紧邻泄殖腔前的腹侧乳头、一对微小的腹侧乳头后泄殖腔和雌性有四到五对背腹乳头，紧邻外阴。给出了在澳大利亚发现的副圆线虫种类的修订密钥。COX1 基因的序列分析证实了P. spratti 的物种状况。

讨论

形态学和分子分析支持P. spratti作为新物种的地位。类圆线虫可能在冈瓦纳的澳大利亚部分有古老的起源。