Aquatic Parasitology Laboratory, School of Fisheries, Aquaculture, & Aquatic Sciences, College of Agriculture, Auburn University, 203 Swingle Hall, Auburn, AL, 36849, USA.
Syst Parasitol. 2023 Dec;100(6):647-656. doi: 10.1007/s11230-023-10114-3. Epub 2023 Sep 28.
During a parasitological survey of freshwater fishes in the Mekong River Delta, Vietnam, disporic plasmodia containing myxospores morphologically consistent with Ellipsomyxa Køie, 2003 (Bivalvulida) were observed infecting the gall bladder of Pangasius macronema Bleeker (Siluriformes: Pangasiidae). Herein, we use morphology and small subunit ribosomal DNA (SSU rDNA, 18S) sequence data to describe Ellipsomyxa intravesica Ksepka & Bullard n. sp. and relate it to other myxozoans. The new species resembles Ellipsomyxa adlardi Whipps & Font, 2013, which infects the naked goby, Gobiosoma bosc (Lacepede) (Gobiiformes: Gobiidae) in Lake Pontchartrain, Louisiana, but differs from it by having a longer myxospore (mean = 13.3; range = 12.0-15.0 vs. 12.4; 11.3-14.4) and shorter polar capsules (3.7; 3.0-4.0 vs. 4.3; 3.9-4.9). The 18S phylogenetic analysis recovered the sequence of the new species sister to those ascribed to Ellipsomyxa ariusi Chandran, Zacharia, Sathianandan & Sanil, 2020 and Ellipsomyxa sp. (MK561979); both of which infect the gall bladder of the threadfin sea catfish, Arius arius (Hamilton) (Siluriformes: Ariidiae) from the southwest coast of India. Consistent with previous phylogenetic analyses of Ellipsomyxa spp., Ellipsomyxa was recovered as monophyletic. The new species is the first species of Ellipsomyxa reported from a freshwater fish in Asia and the first myxozoan reported from P. macronema.
在越南湄公河三角洲的淡水鱼类寄生虫学调查中，观察到含有形态上与 2003 年科伊氏（Bivalvulida）Ellipsomyxa 一致的孢子虫的双孢子虫，感染 Pangasius macronema Bleeker（Siluriformes：Pangasiidae）的胆囊。本文使用形态学和小亚基核糖体 DNA（SSU rDNA，18S）序列数据来描述 Ellipsomyxa intravesica Ksepka & Bullard n. sp.，并将其与其他粘孢子虫相关联。新物种与感染路易斯安那州庞恰特雷恩湖裸盖鱼 Gobiosoma bosc（Lacepede）（Gobiiformes：Gobiidae）的 Ellipsomyxa adlardi Whipps & Font，2013 相似，但具有更长的孢子（平均= 13.3；范围= 12.0-15.0 与 12.4；11.3-14.4）和更短的极囊（3.7；3.0-4.0 与 4.3；3.9-4.9）。18S 系统发育分析恢复了新物种的序列与归属于 Ellipsomyxa ariusi Chandran、Zacharia、Sathianandan 和 Sanil，2020 和 Ellipsomyxa sp.（MK561979）的序列密切相关；两者均感染印度西南海岸的线纹长须鲸 Arius arius（Hamilton）（Siluriformes：Ariidiae）的胆囊。与 Ellipsomyxa spp. 的先前系统发育分析一致，Ellipsomyxa 被恢复为单系。新物种是亚洲淡水鱼类中报道的第一个 Ellipsomyxa 物种，也是 P. macronema 中报道的第一个粘孢子虫。
