Scuticociliatosis caused by Uronema sp. in ten different ornamental aquarium reef fish in Brazil

Abstract Scuticociliatosis, caused by an opportunistic ciliate protozoan, is responsible for significant economic losses in marine ornamental fish. This study reports the occurrence of Uronema spp., parasitizing ten species of marine reef fish at an ornamental fish wholesaler: Blue green damselfish (Chromis viridis), Vanderbilt’s Chromis (Chromis vanderbilti), Pennant coralfish (Heniochus acuminatus), Threespot angelfish (Apolemichthys trimaculatus), Goldspotted angelfish (Apolemichthys xanthopunctatus), Sea goldie (Pseudanthias squamipinnis), Orchid dottyback (Pseudochromis fridmani), Threadfin butterflyfish (Chaetodon auriga), Vagabond butterflyfish (Chaetodon vagabundus), and Bluecheek butterflyfish (Chaetodon semilarvatus). Diseased fish showed disorders such as hemorrhages and ulcerative lesions on the body surface. Histopathological analysis of the muscle, liver, gut, kidney, spleen, gills, and stomach revealed hemorrhages and degeneration of muscle fiber, vacuolar degeneration of hepatocyte, inflammatory process and granuloma in the liver, atrophy of intestinal villi, inflammatory process and granuloma in the kidney, melanomacrophage centers, as well as inflammatory process in the spleen, epithelial cells hyperplasia and granuloma formation in the gills, and vacuolar degeneration and eosinophils in the stomach. Due to the severity of the disease, it is necessary to implement biosecurity measures with rapid and accurate diagnosis to minimize the risk of economic losses caused by Uronema spp.**摘要**：盾纤毛虫病（Scuticociliatosis）是一种由机会性纤毛原生动物引发的疾病，给海水观赏鱼产业造成了显著的经济损失。本研究报道了在一家观赏鱼批发商处，尾丝虫属（Uronema spp.）寄生于10种海水礁岩鱼类的情况，涉及物种分别为：蓝绿雀鲷（Chromis viridis）、凡氏光鳃鱼（Chromis vanderbilti）、马夫鱼（Heniochus acuminatus）、三点阿波鱼（Apolemichthys trimaculatus）、金点阿波鱼（Apolemichthys xanthopunctatus）、金花鮨（Pseudanthias squamipinnis）、弗里德曼拟雀鲷（Pseudochromis fridmani）、丝蝴蝶鱼（Chaetodon auriga）、漂泊蝴蝶鱼（Chaetodon vagabundus）以及蓝颊蝴蝶鱼（Chaetodon semilarvatus）。患病鱼体表现出体表出血、溃疡病灶等病症。对肌肉、肝脏、肠道、肾脏、脾脏、鳃及胃部进行组织病理学分析后发现：肌纤维存在出血与变性现象，肝细胞出现空泡变性；肝脏可见炎症反应与肉芽肿形成；肠绒毛发生萎缩；肾脏存在炎症反应与肉芽肿；观察到黑色素巨噬细胞中心；脾脏发生炎症反应；鳃部上皮细胞增生并形成肉芽肿；胃部出现空泡变性与嗜酸性粒细胞浸润。鉴于该疾病的严重危害性，需实施结合快速精准诊断的生物安全防控措施，以尽可能降低尾丝虫属感染引发的经济损失风险。