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美國(guó)亞歷山大大學(xué)的Don Lightner 教授可以說是世界上唯一的蝦病專家。
關(guān)于此人的信息,大家可以上網(wǎng)去查,如果英文夠給力。
Early Mortality Syndrome 對(duì)蝦早期死亡癥狀,下面簡(jiǎn)稱EMS,于2010年在中國(guó)南方和海南省被發(fā)現(xiàn),并于2011年擴(kuò)散到越南和馬來西亞。
該疾病的死亡率出現(xiàn)在投苗20至30天后,斑節(jié)對(duì)蝦和南美白對(duì)蝦都曾有被感染的報(bào)道。病蝦表現(xiàn)出的癥狀包括昏沉和絕食,嚴(yán)重者的死亡率可以高達(dá)100%。顯微解剖發(fā)現(xiàn)病蝦的肝胰腺嚴(yán)重萎縮并有黑白條紋,蝦殼變軟病產(chǎn)生黑色的色斑。
組織病理學(xué)觀察后發(fā)現(xiàn),EMS的影響似乎僅限于 肝胰腺 , 肝胰腺 的退行性病變可能是由有毒物質(zhì)造成的。與此同時(shí),B1 黃曲霉毒素( aflatoxin B1 )和能抑制有絲分裂的笨菌靈( benomyl )都能給對(duì)蝦的 肝胰腺 造成類似病變。
但導(dǎo)致EMS的病原依然沒有弄清楚。目前的研究已表面飼料和甲殼動(dòng)物殺蟲劑不會(huì)導(dǎo)致EMS。而且,冰凍保存的EMS樣本不會(huì)感染其他健康的蝦。至今為止,在實(shí)驗(yàn)室條件下無法誘導(dǎo)出于EMS相同的表型癥狀。
原文如下
In 2010, Early Mortality Syndrome (EMS), a new shrimp disease, appeared on shrimp farms in southern China and on China’s Hainan Island. By early 2011, it spread to Vietnam and Malaysia.
The disease appears within 20 to 30 days after stocking. Giant tiger shrimp, Penaeus monodon, and Western white shrimp, P. vannamei, are affected. Diseased shrimp become lethargic, stop eating and mortalities approach 100% in severely affected ponds. The hepatopancreas shrinks and has whitish and black streaks. Other signs include a soft, generally darker shell and mottling of the carapace.
In samples of shrimp preserved for histology, the effects of EMS appear to be limited to the hepatopancreas. The degenerative pathology of the hepatopancreas suggests a toxic etiology. Similar lesions have been reported in the hepatopancreases of shrimp exposed to aflatoxin B1 (a toxin produced by many species of the Aspergillus fungus) and benomyl (a mitosis inhibitor).
Studies to determine the cause of EMS have not been successful. Researchers have ruled out commercial feeds used on shrimp farms where EMS occurred and a crustacide commonly used in the region to kill whitespot vectors. Frozen samples of shrimp with EMS did not infect other shrimp. To date, the researchers have not been able to experimentally induced lesions of the hepatopancreas consistent with those observed in shrimp with EMS.
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