Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, 37005 České Budějovice, Czech Republic.
Freeman Aquatic Biology, Texas State University-San Marcos, San Marcos, Texas 78666-4616, USA.
Parasite. 2023;30:33. doi: 10.1051/parasite/2023036. Epub 2023 Sep 7.
Based on light microscopical and scanning electron microscopical (SEM) examinations, two North American species of Spinitectus Fourment, 1884, S. acipenseri Choudhury & Dick, 1992 and S. micracanthus Christian, 1972 (Nematoda, Cystidicolidae) are redescribed from museum voucher specimens (S. acipenseri) and those newly collected from centrarchid and some other fishes in the Upper San Marcos River in Texas and the Santee River in South Carolina, USA. The first use of SEM to study S. acipenseri, a parasite of lake sturgeon Acipenser fulvescens Rafinesque (Acipenseridae) in Canada, made it possible to describe dorsal and ventral lips, amphids and sublabia, and the presence of a dorsal barb on the right spicule, which was confirmed to be the most characteristic feature of this species. The SEM study of S. micracanthus, a parasite mainly of centrarchids, enabled us to correctly determine the location of the excretory pore in relation to rings of cuticular spines in the male, and to describe the exact structure of the tip of the male tail, sublabia, phasmids and the presence of a median ventral protuberance on the male tail. Some taxonomic problems of North American species of Spinitectus are discussed. Filaria serrata Linton, 1901 is considered a junior synonym of S. oviflagellis Fourment, 1884. To date, there are 13 valid species of Spinitectus parasitising fishes in North America. Keys to species of Spinitectus-like nematodes from fishes in North American waters are provided.
基于光镜和扫描电子显微镜（SEM）检查，重新描述了来自博物馆凭证标本的北美两种 Spinitectus Fourment，1884 物种，即 S. acipenseri Choudhury & Dick，1992 和 S. micracanthus Christian，1972（线虫，Cystidicolidae），以及从美国德克萨斯州上圣马科斯河和南卡罗来纳州桑蒂河的鲈形目和其他一些鱼类中采集的新样本。首次使用 SEM 研究 S. acipenseri，一种加拿大湖鲟 Acipenser fulvescens Rafinesque（鲟科）的寄生虫，使得描述背唇和腹唇、耳状感器和下唇、右刺的背棘成为可能，这被证实是该物种最具特征的特征。对 S. micracanthus 的 SEM 研究，一种主要寄生在鲈形目鱼类的寄生虫，使我们能够正确确定雄虫排泄孔与角质刺环的位置，并描述雄虫尾部末端、下唇、感觉器和雄虫尾部中间腹突的确切结构。讨论了北美的 Spinitectus 物种的一些分类问题。Filaria serrata Linton，1901 被认为是 S. oviflagellis Fourment，1884 的次同物异名。迄今为止，北美有 13 种有效的 Spinitectus 寄生鱼类。提供了北美水域鱼类中类似 Spinitectus 线虫的物种的关键。
