Müller Maria I, Naldoni Juliana, Corrêa Lincoln L, Adriano Edson A
Department of Ecology and Evolutionary Biology, Federal University of São Paulo (UNIFESP), Diadema, SP, 09972-270, Brazil.
Department of Ecology and Evolutionary Biology, Federal University of São Paulo (UNIFESP), Diadema, SP, 09972-270, Brazil.
Microb Pathog. 2022 Apr;165:105464. doi: 10.1016/j.micpath.2022.105464. Epub 2022 Mar 2.
The present study describes two new Myxobolus species infecting the gills of Semaprochilodus insignis, the most consumed freshwater fish species in the Brazilian Amazon. The fish specimens were caught in the Tapajós River, in the state of Pará, and the morphological, ultrastructural, small subunit ribosomal DNA (ssrDNA), and phylogenetic data of the myxosporean species were obtained. Two species of Myxobolus were found in the gills of S. insignis. Myxobolus maiai n. sp. developed in the gill filaments, and mature myxospores were round-shaped from the frontal view, measuring 12.5-14.8 (13.9 ± 0.5) μm in length, 11.4-13.8 (12.3 ± 0.5) μm in width, and have a thickness of 6.4-7.7 (6.9 ± 0.6) μm in the lateral view, with symmetric values. Its polar capsules were 4.4-6.6 (5.5 ± 0.5) μm in length and 2.3-3.7 (3.0 ± 0.3) μm in width, and the polar tubules had 4 - 5 coils. Myxobolus iarakiensis n. sp. was found infecting the gill arch. Mature myxospores were oval-shaped from the frontal view, and measured 6.7-8.6 (8.0 ± 0.4) μm in length, 4.5-6.3 (5.6 ± 0.4) μm in width, and had a thickness of 2.7-4.7 (3.8 ± 0.5) μm in the lateral view, with symmetric values. Its polar capsules were 2.1-3.7 (2.9 ± 0.3) μm in length and 1.1-2.0 (1.5 ± 0.2) μm in width, and its polar tubules had 4 - 5 coils. The ssrDNA based phylogeny showed these two novel species as grouping in a clade composed of parasite species of Prochilodontidae hosts.
本研究描述了两种感染巴西亚马逊地区消费最多的淡水鱼品种——细纹半脂鲤鳃部的新粘体虫物种。鱼标本采自帕拉州的塔帕若斯河，并获取了粘孢子虫物种的形态学、超微结构、小亚基核糖体DNA（ssrDNA）及系统发育数据。在细纹半脂鲤的鳃部发现了两种粘体虫。马亚伊粘体虫新种在鳃丝中发育，成熟粘孢子从正面看呈圆形，长12.5 - 14.8（13.9±0.5）μm，宽11.4 - 13.8（12.3±0.5）μm，侧面看厚度为6.4 - 7.7（6.9±0.6）μm，数值对称。其极囊长4.4 - 6.6（5.5±0.5）μm，宽2.3 - 3.7（3.0±0.3）μm，极丝有4 - 5圈。伊拉基粘体虫新种被发现感染鳃弓。成熟粘孢子从正面看呈椭圆形，长6.7 - 8.6（8.0±0.4）μm，宽4.5 - 6.3（5.6±0.4）μm，侧面看厚度为2.7 - 4.7（3.8±0.5）μm，数值对称。其极囊长2.1 - 3.7（2.9±0.3）μm，宽1.1 - 2.0（1.5±0.2）μm，极丝有4 - 5圈。基于ssrDNA的系统发育显示这两个新物种聚集在一个由原唇齿脂鲤科宿主的寄生虫物种组成的分支中。
