摘要
由刺激隐核虫寄生感染而引起的"白点病"成为大黄鱼养殖生产中危害最为严重的病害之一。为研究刺激隐核虫对大黄鱼的致病力及复方中草药HD-2对刺激隐核虫世代繁殖的抑制和阻断其感染的效果,本研究在测定了患病大黄鱼产生刺激隐核虫包囊数量、大小、孵化率和幼虫产率的基础上,测定了幼虫体外存活时间和感染力。同时,研究了HD-2中草药液对刺激隐核虫幼虫、滋养体和包囊的杀除效果以及口服复方中草药HD-2对患病大黄鱼的治疗效果。结果显示,自然患病大黄鱼体型规格与产生包囊总数呈正相关,包囊直径为(340.8±64.9)μm,平均孵化率为76.4%,每个包囊可产生280±42.5个幼虫;幼虫体外最长存活时间超过24 h,幼虫孵化20 h后便丧失感染力。幼虫感染大黄鱼7 d的LD_(90)为9 712个幼虫/尾,LD_(50)为4 366个幼虫/尾。HD-2中草药液可有效杀灭刺激隐核虫幼虫,分别口服含复方中草药5、10和15 g/kg饲料30 d的实验组大黄鱼在LD50攻毒剂量下其相对感染强度较对照组分别下降32.0%、44.5%和51.8%,包囊体积较对照组分别减少35.4%、36.1%和37.3%,孵化率分别下降16.3%、23.3%和27.9%;在LD90攻毒剂量下3个实验组大黄鱼的存活率分别达到40.0%、55.0%和58.3%,显著高于对照组(8.3%),且鳃丝、胸鳍上滋养体数量较对照组显著下降。口服复方中草药HD-2对自然患病大黄鱼的治疗效果表明,采集口服15 d的3组大黄鱼的包囊数量分别较对照组下降73.1%、87.7%和93.8%,鱼体死亡率分别为58.3%、36.7%和21.7%,较对照组83.3%的死亡率明显降低,且用药组大黄鱼的生理状态明显优于对照组。由此可见,口服复方中草药HD-2能有效阻断刺激隐核虫的二次感染,抑制包囊的形成和发育,降低包囊孵化率和幼虫孵化数量,从而有效抑制了虫体的世代繁殖。
The "white spot disease" caused by the parasitic infection of Cryptocaryon irritans has become one of the most serious diseases in the production of Larimichthgs crocea. This study aims to investigate the pathogenicity of C. irritans to L. crocea, as well as the effect of Chinese herbal compound HD-2 on inhibiting the generation reproduction of parasite C. irritans. The number, size, the hatching rate and number of hatched theronts of tomonts produced by natural sick L. crocea were investigated. Then the survival time and infectivity of theront was determined in vitro. The effects of Chinese herbal compound HD-2 on theront, trophont, and tomont, and the therapeutic effects of oral HD-2 on diseased L. crocea were studied. The results showed that the total number of tomonts produced by L. crocea was positively correlated to the fish body weight;the average diameter of tomonts were (340.8±64.9)μm and the hatching rate was 76.4%, and each tomont could produce (280±42.5) theronts;the theront could survive for more than 24 h in vitro and lost their infectivity in 20 h after hatching. The 90% lethal dose (LD90) of L. crocea infected with C. irritans in 7 days was 9 712 theronts/fish and the median lethal dose for 50%(LD50) was 4 366 theronts/fish. HD-2 could kill theront effectively. After oral administration with different doses of HD-2 (control, 0;G1, 5 g/kg;G2, 10 g/kg;G3, 15 g/kg) for 30 days, the relative infection intensity of the L. crocea groups challenged with LD50 decreased by 32.0%, 44.5% and 51.8%, respectively. Meanwhile, the volume of tomonts reduced by 35.4%, 36.1% and 37.3% and the hatching rate reduced by 16.3%, 23.3% and 27.9%, respectively. The fish survival rate of G1, G2 and G3 challenged with LD90 was 40.0%, 55.0% and 58.3%, which was significantly higher than the control group (only 8.3%). Using HD-2 oral treatment for 15 d, the tomonts produced from diseased fish reduced 73.1%, 87.7% and 93.8%, and the fish mortality rate of the three groups were 58.3%, 36.7% and 21.7%, which were significantly lower than the control group (83.3%). The physiological status of L. crocea in the treated group was significantly better than that of the control group. Therefore, HD-2 oral treatment could effectively interrupt the secondary infection of C. irritans, suppress the formation and development of tomonts, reduce the tomont hatching rate and the number of hatching theronts, and then inhibit the generation reproduction of parasite C. irritans.
作者
焦恺强
王印庚
荣小军
陈佳
张正
廖梅杰
李彬
孙陆宇
苏跃中
JIAO Kaiqiang;WANG Yingeng;RONG Xiaojun;CHEN Jia;ZHANG Zheng;LIAO Meijie;LI Bin;SUN Luyu;SU Yuezhong(College of Fisheries and Life Science,Shanghai Ocean University,Shanghai 201306,China;Qingdao National Laboratory for Marine Science and Technology,Laboratory for Marine Fisheries Science and Food ProductionProcesses,Key Laboratory of Maricultural Organism Disease Control,Ministry of Agriculture and Rural Affairs,Yellow Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences,Qingdao 266071,China;State Key Laboratory of Large Yellow Croaker Breeding,Fujian Fuding Seagull Fishing Food Co.Ltd.,Ningde 352103,China;Fujian Da Bei Nong Aquatic Technology Co.,Ltd.,Zhangzhou 363502,China;Fujian Marine Environment & Fishery Resources Monitoring Center,Fuzhou 350003,China)
出处
《水产学报》
CAS
CSCD
北大核心
2019年第5期1326-1337,共12页
Journal of Fisheries of China
基金
福建省科技重大专项(2013NZ0002-5)
国家科技支撑计划(2012BAD17B03)
山东省自主创新与成果转化专项(2014ZZCX06205)
闽海渔合同[2009]2-12号~~
关键词
大黄鱼
刺激隐核虫
复方中草药HD-2
阻断感染
世代繁殖
致病力
Larimichthys crocea
Cryptocaryon irritans
Chinese herbal compound HD-2
interrupt infection
generation reproduction
pathogenicity
