Sumuduni Bannak G D, Munasinghe Dona H N, Arulkanthan Appudurai
Department of Zoology, Faculty of Science, University of Ruhuna, Matara, Sri Lanka.
Department of Veterinary Pathobiology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Peradeniya, Sri Lanka.
Int J Vet Sci Med. 2018 Sep 5;6(2):165-171. doi: 10.1016/j.ijvsm.2018.08.006. eCollection 2018 Dec.
is a digenean that requires three host species to complete its life cycle. This study was conducted to observe the damage caused by two life stages of the on its host species. The snail was induced to shed cercariae by exposing to sunlight and specimens of koi carps were experimentally infected with cercariae. Gills of two infected fish were killed and fixed in Bouin's solution daily for 21 days. Infected fish were continuously fed to a pond heron () for three weeks and therafter the bird was killed. Small intestine was resected as duodenum, jejunum, and ileum and fixed in formol saline. Gills and small intestine were prepared to study the histopathological damages. Flared opercula with protruding gills and increased respiratory rate were identified as the primary clinical signs of the fish. Encysted metacercariae were observed in the basal, middle and in the apical portion of the gills' filaments and gradual distortions and extensive proliferation of the cartilage of the gills resulted in loss of the respiratory epithelium. A progression of fibroblast to chondroblast encapsulation of the parasite was observed in the gill of fish as a host response. The duodenum of the heron was severely infected with adult parasites than jejunum and ileum. Flukes were observed in the villi, mucosae, submucosae, and also in the tunica muscularis of the duodenum. In conclusion, this study revealed that the heavy infection of could cause severe pathological lesions in both koi carps and pond heron.
是一种复殖吸虫，需要三种宿主物种来完成其生命周期。本研究旨在观察该吸虫两个生活阶段对其宿主物种造成的损害。通过暴露于阳光下诱导蜗牛排出尾蚴，并将锦鲤标本实验性感染尾蚴。每天将两条受感染鱼的鳃杀死并固定在布氏液中，持续21天。将受感染的鱼连续投喂给一只池鹭三周，之后将这只鸟杀死。切除小肠的十二指肠、空肠和回肠，并固定在甲醛生理盐水中。制备鳃和小肠以研究组织病理学损伤。鳃盖张开、鳃突出和呼吸频率增加被确定为鱼的主要临床症状。在鳃丝的基部、中部和顶端观察到包囊后尾蚴，鳃软骨逐渐变形和广泛增生导致呼吸上皮丧失。在鱼的鳃中观察到成纤维细胞向软骨细胞对寄生虫的包囊化过程，这是宿主的一种反应。池鹭的十二指肠比空肠和回肠受到成虫寄生虫的严重感染。在十二指肠的绒毛、黏膜、黏膜下层以及肌层中都观察到了吸虫。总之，本研究表明该吸虫的重度感染可在锦鲤和池鹭中引起严重的病理病变。
