PURPOSE Despite the fact that Okinawa Prefecture represents a very interesting subtropical region of Japan, its fauna of nematodes parasitizing fishes is still little-known. Therefore, new data are needed to recognize the species composition of these parasites in this zoogeographically remarkable region. METHODS Helminthological examinations of some freshwater and brackish-water fishes in Okinawa Prefecture carried out in the years 2010, 2016 and 2018, revealed two new and four insufficiently known species of spirurid nematodes (Spirurida), all gastrointestinal parasites. These were studied with the use of light and scanning electron microscopy. RESULTS All nematode species recorded are described: Rhabdochonidae: Rhabdochona honshuensis Moravec et Nagasawa, 1989 from Glossogobius celebius (Valenciennes) (Gobiidae, Perciformes) (new host), Rhabdochona iriomotensis sp. nov. from Ophieleotris sp. (Eleotridae, Perciformes) and Rhabdochona sp. (only females) from Eleotris acanthopoma Bleeker and E. fusca (Forster) (both Eleotridae, Perciformes); Cystidicolidae: Spinitectus mirabilis sp. nov. from Kuhlia rupestris (Lacepède) (Kuhliidae, Perciformes) and Spinitectus sp. larvae from E. acanthopoma; and Camallanidae: Procamallanus (Spirocamallanus) sp. (fourth-stage larva) from Yongeichthys criniger (Valenciennes) (Gobiidae, Perciformes). Rhabdochona iriomotensis sp. nov. is very similar to R. honshuensis, but differs from it in the presence of well-developed ventral precloacal ridges. Spinitectus mirabilis sp. nov. differs from its congeners and all other cystidicolids in having eggs provided with both lateral swellings and polar filaments. CONCLUSIONS In addition to the discovery of two new nematode species, Rhabdochona iriomotensis sp. nov. and Spinitectus mirabilis sp. nov., the findings of all other species represent new host and geographical records. Rhabdochona denudata honshuensis Moravec et Nagasawa, 1989 is elevated to the level of an independent species R. honshuensis.

中文翻译：

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日本冲绳县淡水和咸水鱼类的一些螺旋线虫（螺旋线虫），以及两个新物种的描述。

目的 尽管冲绳县代表了日本一个非常有趣的亚热带地区，但其寄生鱼类的线虫动物群仍然鲜为人知。因此，需要新的数据来识别这个动物地理上显着的区域中这些寄生虫的物种组成。方法 冲绳县于 2010 年、2016 年和 2018 年对一些淡水和半咸水鱼类进行了蠕虫学检查，发现了两种新的螺旋线虫（Spirurida）和四种未知的螺旋线虫（螺旋线虫），它们都是胃肠道寄生虫。使用光学显微镜和扫描电子显微镜对这些进行了研究。结果 记录的所有线虫物种都被描述为：Rhabdochonidae：Rhabdochona honshuensis Moravec et Nagasawa，1989 来自 Glossogobius celebius (Valenciennes) (Gobiidae，Perciformes)（新宿主），Rhabdochona iriomotensis sp. 十一月 来自 Ophieleotris sp. (Eleotridae, Perciformes) 和 Rhabdochona sp。（仅雌性）来自 Eleotris acanthopoma Bleeker 和 E. fusca (Forster)（两者都是 Eleotridae，Perciformes）；Cystidicolidae：Spinitectus mirabilis sp。十一月 来自 Kuhlia rupestris (Lacepède) (Kuhliidae, Perciformes) 和 Spinitectus sp。棘球虫幼虫；和Camallanidae：Procamallanus (Spirocamallanus) sp。（第四阶段幼虫）来自 Yongeichthys criniger (Valenciennes) (Gobiidae, Perciformes)。Rhabdochona iriomotensis sp. 十一月 与 R. honshuensis 非常相似，但与它的不同之处在于存在发达的腹侧泄殖腔前脊。Spinitectus mirabilis sp。十一月 与它的同类和所有其他囊胞菌的不同之处在于，卵具有侧向肿胀和极丝。结论 除了发现了两种新的线虫物种 Rhabdochona iriomotensis sp。十一月 和 Spinitectus mirabilis sp。11 月，所有其他物种的发现代表了新的宿主和地理记录。Rhabdochona denudata honshuensis Moravec et Nagasawa, 1989 被提升到独立物种 R. honshuensis 的水平。