Aquaculture Center of São Paulo State University (CAUNESP), Jaboticabal, Brazil.
Vet Parasitol. 2013 Jan 16;191(1-2):154-60. doi: 10.1016/j.vetpar.2012.07.030. Epub 2012 Aug 4.
Chilodonelids are small ciliated protozoans found worldwide and can be dangerous in culture conditions. This study presents morphometric data on the ciliate Chilodonella that is found in cultured Nile tilapia (Oreochromis niloticus), native bait fish tuvira (Gymnotus aff. inaequilabiatus) and native pacu (Piaractus mesopotamicus) and includes a histopathological assessment of the changes that occur in the pacu. For parasitic diagnosis, skin and gill samples were scraped onto slides, dried at room temperature, stained with Giemsa or impregnated with silver nitrate, and the measurements were obtained from photomicrographs. In the diseased pacu, the first gill arch was collected and fixed in a 10% buffered formalin solution for histopathological analysis. Parasite specimens from the different collection sites were identified morphologically as C. hexasticha Kiernik (1909). Diseased fish exhibited depigmentation, skin ulceration, scale loss, excessive mucus production and gill lesions. Histopathological analysis of pacu gills displayed epithelial proliferation with mononuclear inflammatory infiltrate, hemorrhages, and scattering necrosis. In Brazilian-farmed fish this is the first record of C. hexasticha, which has great pathogenic potential in cultured freshwater species. In addition, two new hosts are presented.
纤毛原虫 Chilodonella 广泛分布于世界各地，在培养条件下可能具有危害性。本研究提供了在养殖的尼罗罗非鱼（Oreochromis niloticus）、本地诱饵鱼图维亚鱼（Gymnotus aff. inaequilabiatus）和本地淡水白鲳（Piaractus mesopotamicus）中发现的纤毛原虫 Chilodonella 的形态计量学数据，并包括对淡水白鲳发生的变化进行组织病理学评估。为了进行寄生虫诊断，从皮肤和鳃上刮取样本并涂载于载玻片上，在室温下干燥，用吉姆萨或硝酸银染色，然后从显微镜照片中获取测量值。在患病的淡水白鲳中，采集第一鳃弓并固定在 10%缓冲福尔马林溶液中进行组织病理学分析。从不同采集地点的寄生虫标本通过形态学鉴定为六刺纤毛原虫 C. hexasticha Kiernik（1909）。患病鱼类表现出褪色、皮肤溃疡、鳞片脱落、过度黏液分泌和鳃损伤。对淡水白鲳的鳃进行组织病理学分析显示上皮细胞增生，伴有单核炎性浸润、出血和散在性坏死。在巴西养殖的鱼类中，这是首次记录到六刺纤毛原虫，它对养殖淡水物种具有很大的致病潜力。此外，还介绍了两种新的宿主。
