Abstract：
The coastal waters of Vietnam are home to a wide diversity of fishes, but the parasite diversity of these potential hosts is much less well characterized. To begin addressing this knowledge gap, we carried out surveys of myxozoan parasites in fishes collected from Nha Trang Bay in Vietnam\'s East Sea in 2018-2019. Mugilid fishes were collected in March-April 2018, January-February 2019, and November-December 2019, and examined for myxozoans. Myxospores consistent with those of the genus Ellipsomyxa were found in the gall bladder of four mullet species, and we thoroughly characterized those from Planiliza melinoptera. Myxospores were elliptoid and devoid of striation, with a distinct sinuous suture line. Polar capsules were pyriform and oriented toward the poles of the spore. Morphological features were compared to nominal species and this species from Vietnam was distinct. Phylogenetic analysis based on partial small subunit rDNA sequence revealed that broadly, Ellipsomyxa species split into three phylogenetic lineages, and although in some branches there are groupings by host family, habitat or locality, there are no clear phylogenetic patterns. The new species we encountered in P. melinoptera had a close sister relationship with Ellipsomyxa adlardi, with both species part of a larger subclade within the Ellipsomyxa lineage. Despite this phylogenetic similarity, these species were morphologically distinct, and partial large subunit DNA sequences were only 93% similar to each other. A combination of the morphological characteristics and molecular data suggest that this is an undescribed species and we propose the name Ellipsomyxa gordeyi n. sp.
摘要：
越南沿海水域有各种各样的鱼类，但是这些潜在宿主的寄生虫多样性特征要少得多。为了开始解决这个知识差距，我们在2018-2019年对越南东海芽庄湾收集的鱼类中的粘液虫寄生虫进行了调查。在2018年3月至4月，2019年1月至2月和2019年11月至12月收集了Mugilid鱼类，并检查了粘虫。在四种鱼的胆囊中发现了与Ellipsomyxa属一致的粘孢子，我们彻底地描述了Planilizamelinoptera的特征。粘孢子呈椭圆形，没有条纹，有明显的弯曲缝合线。极性胶囊是梨形的，朝向孢子的两极。将形态特征与名义物种进行了比较，来自越南的该物种与众不同。基于部分小亚基rDNA序列的系统发育分析显示，Ellipsomyxa物种分为三个系统发育谱系，尽管在某些分支机构中，按寄宿家庭分组，栖息地或地方，没有明确的系统发育模式。我们在P.melinoptera中遇到的新物种与Ellipsomyxaadlardi有亲密的姐妹关系，这两个物种都属于Ellipsomyxa谱系中一个更大的亚进化枝。尽管有这种系统发育相似性,这些物种在形态上不同，和部分大亚基DNA序列彼此只有93％相似。形态特征和分子数据的结合表明，这是一个未描述的物种，我们提出了名称Ellipsomyxagordeyin.sp。
