Departamento de Parasitologia da Universidade Estadual de Campinas-(UNICAMP), Caixa Postal 6109, CEP 13083-970, Campinas, SP, Brazil.
Vet Parasitol. 2011 May 11;177(3-4):247-55. doi: 10.1016/j.vetpar.2010.12.008. Epub 2010 Dec 14.
A new myxosporean species, Henneguya eirasi n. sp., is described parasitizing the gill filaments of Pseudoplatystoma corruscans and Pseudoplatystoma fasciatum (Siluriformes: Pimelodidae) caught in the Patanal Wetland of the state of Mato Grosso, Brazil. The parasite formed white, elongated plasmodia measuring up to 3mm. Mature spores were ellipsoidal in the frontal view, measuring 37.1 ± 1.8 μm in total length, 12.9 ± 0.8 μm in body length, 3.4 ± 0.3 μm in width, 3.1 ± 0.1 μm in thickness and 24.6 ± 2.2 μm in the caudal process. Polar capsules were elongated and equal in size, measuring 5.4 ± 0.5 μm in length and 0.7 ± 0.1 μm in width. Polar filaments had 12-13 coils. Histopathological analysis revealed that the parasite developed in the sub-epithelial connective tissue of the gill filaments and the plasmodia were surrounded by a capsule of host connective tissue. The plasmodia caused slight compression of the adjacent tissues, but no inflammatory response was observed in the infection site. Ultrastructure analysis revealed a single plasmodial wall connected to the ectoplasmic zone through numerous pinocytotic canals. The plasmodial wall exhibited numerous projections and slightly electron-dense material was found in the ectoplasm next to the plasmodial wall, forming a line just below the wall. Partial sequencing of the 18S rDNA gene of H. eirasi n. sp. obtained from P. fasciatum resulted in a total of 1066 bp and this sequence did not match any of the Myxozoa available in the GenBank. Phylogenetic analysis revealed the Henneguya species clustering into clades following the order and family of the host fishes. H. eirasi n. sp. clustered alone in one clade, which was the basal unit for the clade composed of Henneguya species parasites of siluriform ictalurids. The prevalence of the parasite was 17.1% in both fish species examined. Parasite prevalence was not influenced by season, host sex or host size.
一种新的粘孢子虫，即 Henneguya eirasi n. sp.，被描述为寄生在巴西马托格罗索州潘塔纳尔湿地捕获的尖吻鲈和锯脂鲤（Siluriformes：Pimelodidae）的鳃丝上。寄生虫形成白色、拉长的原质团，最长可达 3mm。成熟孢子在额面呈椭圆形，全长 37.1 ± 1.8μm，体长 12.9 ± 0.8μm，宽 3.4 ± 0.3μm，厚 3.1 ± 0.1μm，尾突长 24.6 ± 2.2μm。极囊狭长且大小相等，长 5.4 ± 0.5μm，宽 0.7 ± 0.1μm。极丝有 12-13 圈。组织病理学分析显示，寄生虫在鳃丝的上皮下结缔组织中发育，原质团被宿主结缔组织的囊包围。原质团对相邻组织造成轻微的压迫，但在感染部位没有观察到炎症反应。超微结构分析显示，单个原质团壁通过许多胞饮小泡与外质区相连。原质团壁有许多突起，在外质区靠近原质团壁的地方发现有稍电子致密物质，形成一条线，正好在壁的下方。从感染锯脂鲤的 Henneguya eirasi n. sp. 中获得的 18S rDNA 基因的部分序列全长 1066bp，与 GenBank 中可用的任何粘孢子虫都不匹配。系统发育分析显示，按照宿主鱼类的目和科，Henneguya 种聚类成簇。H. eirasi n. sp. 独自聚类在一个簇中，该簇是由 Siluriformes ictalurids 寄生虫的 Henneguya 种组成的簇的基本单位。在两种检查的鱼类中，寄生虫的流行率均为 17.1%。寄生虫的流行率不受季节、宿主性别或宿主大小的影响。
