中国水产科学2017，Vol.24Issue(3)：596-605,10.DOI:10.3724/SP.J.1118.2017.15200
津冀地区养殖三疣梭子蟹大量死亡的病原和病理分析
Etiological and pathological analyses of massive mortality in cultured crabPortunus trituberculatusalong the coasts of Tianjin and Hebei, China
摘要
Abstract
In July 2014, the widely cultured pond crabPortunus trituberculatus (commonly called Chinese swim-ming crab) had a disease outbreak along the coasts of Tianjin and Hebei provinces, China, resulting in massive mortalities. Symptoms of two different illnesses appeared in the crabs. One was white muscle disease (WMD), with its symptoms being anorexia, slowed movement, and the muscles turning opaque white and finally emulsify-ing into a toothpaste-like consistency. Mortality among the crabs displaying WMD was 60%?70%. The other was milky disease (MD), which displayed as a softened carapace, cessation of feeding, slowed movement, and the muscles similarly turning opaque white but then becoming watery ('milky') and finally shrinking; the coelomic fluid and the deteriorated tissue leaked from the body and had not coagulated. Mortality among the crabs display-ing MD exceeded 90%. According to the characteristics of the epidemic, and histopathological and ultrastructural analyses, the supposed cause of WMD was infection with a microsporidian. The parasite was ellipsoid, measured (1544±250) nm, and had the following structure: pole filament (8 or 9 laps), spore wall [thickness (130±22) nm], cilium (length 120?500 nm), polaroplast [(726±200) nm], pole tube, anchoring disk, plasma membrane and nu-cleus. The MD outbreak was caused byHematodinium sp., a monad, sized 8?10μm, with an oval shape, and wrinkled and raised surface; its basic structure was a cell wall, multiple nuclei, cilium and other structures. Histo-pathological examination showed that the two kinds of diseased crabs had significantly different muscle lesions. The crabs associated with WMD had many microsporidia adhering to their muscle fibers, causing the fibers to break, collapse and necrosis, finally reducing them to muscle bundles. SEM observations showed that the muscle cells became fused and acquired a large number of vacuoles, while the mitochondria and endoplasmic reticulum disintegrated and disappeared. In comparison, the gap in the muscle bundles was bigger in cases of MD, in which numerous parasites occupied or adhered to the muscle fibers, resulting in the fibers rupture, disintegration, and resolvable necrosis. Electron microscopy also confirmed that the two different parasites could infect the same tis-sue in the same crab, and both parasites could enter the disintegrated cytoplasm after muscle cell fusion. Since the initial epidemic of these diseases, other occurrences of WMD and MD have tended to cause a higher level of mor-tality, causing concern as significant diseases currently effecting the crab-farming industry.关键词
三疣梭子蟹/肌肉白浊病/牛奶病/微孢子虫/血卵涡鞭虫/溶解性坏死Key words
Portunus trituberculatus/white muscle disease/milky disease/microsporidian/Hematodiniumsp/resolvable necrosis分类
农业科技引用本文复制引用
王印庚,杨洋,张正,李彬,廖梅杰,邓威,孟繁林..津冀地区养殖三疣梭子蟹大量死亡的病原和病理分析[J].中国水产科学,2017,24(3):596-605,10.基金项目
"十二五"国家科技支撑计划课题(2012BAD17B03) （2012BAD17B03）
山东省自主创新与成果转化专项(2014ZZCX06205) （2014ZZCX06205）
山东省海洋经济创新发展区域示范项目——山东省海水养殖重要疾病高效专用药物研发及产业化项目. （）
