Title

养殖大菱鲆蟹栖异阿脑虫感染及其危害

Translated Titles

Mesanphrys carcini Causing Severe Scuticociliatosis in Farmed Turbot Scophthalmus maximus in China

Authors

王印庚(Yin-Geng Wang);陈洁君(Jie-Jun Chen);秦蕾(Lei Qin)

Key Words

大菱鲆 ; 蟹栖异阿脑虫 ; 盾纤虫病 ; 组织病理学 ; Scophthalmus maximus ; Mesanophrys carcini ; scuticociliatosis ; histopathology

PublicationName

中國水產科學

Volume or Term/Year and Month of Publication

12卷5期(2005 / 09 / 01)

Page #

594 - 601

Content Language

簡體中文

Chinese Abstract

从养殖大菱鲆(Scophthalmus maximus)患病鱼体中分离出一种寄生性纤毛虫,通过活体观察、碳酸银法染色和扫描电镜对其形态学进行特征分析。经鉴定,该纤毛虫为蟹栖异阿脑虫(Mesanophrys carcini Groliere & Leglise 1977),隶属于寡膜纲、盾纤目、嗜污科、异阿脑虫属。患病鱼常表现为静伏池底,体色变暗,活力弱,摄食差,生长减慢,并发生急、慢性死亡。最明显的特征是病灶部位变白,略有浮肿,触摸柔软。流行病学特征显示,在大菱鲆的苗期、养成期、亲鱼培育期均可发生纤毛虫感染,幼鱼期发生率较高,发病水温14~20℃,盐度12~40。组织病理学观察分析表明,病灶组织处以盾纤虫为主要人侵微生物,常伴有细菌存在,但没有发现病毒性细胞病变和霉菌等其他寄生生物。

English Abstract

Turbot (Scophthalmus maximus) is one of the most important cultured species in Europe. It was introduced into China in 1992. With the consequential successes in artificial breeding in 1997, the commercial culture has rapidly spread along the coast of North China and has become an important industry. Recently, about 50 million juveniles were produced, and more than 20000 t marketable fish was yielded which totally valued about US $250 million. However, the rapid expansion of culture has led to occurrence of diseases, of which scuticociliatosis has been considered as a serious disease in the industry. An intensive investigation was conducted along the coast of Shandong Province from 2003 to 2004, during the outbreaks of scuticociliatosis. All cases with scuticociliatosis resulted in high mortalities, which even reached up to 90%. The disease normally occurred under the conditions of temperature 14-20, and salinity 12-40. In addition, the juveniles and young adults were sensitive to the infection than the adults. Upon the isolation and cultivation of the ciliates, morphological studies were carried out by means of smear observation, specimens stained with the silver carbonate method and Chatton-Lwoff silver impregnation techniques as well as scanning electron microscopy. The ciliates were rather variable in size, usually (28-48 µm) X (15-29 µm), elongated and ovoid with a pointed anterior and a rounded posterior. A contractile vacuole and a caudal cilium were clearly shown, while 11 bipolar somatic kineties arranged in nonspiral all over the body. The buccal cavity, anteriorly distributed and occupied nearly 1/3 of the body length. There were three membranes (Ml, M2, M3) and a paroral membrane (PM) within the buccal cavity. PM extended from the posterior end of M2 to the end of cytostome. There were two nucleuses, one large round to slightly oval macronucleus and an adjacent small micronucleus, locating in the middle of the body. Based on the above characteristics, the histophagous ciliate was identified as Mesanophrys carcini. Histopathological studies revealed the massive ciliates around the foci, generally causing cellular degeneration, hyperplasia and tissue necrosis. The susceptible tissues included skin, gills, muscle, intestine, brain and cavities amongst the internal organs. Mesanophrys carcini were found to be dominant within the infected tissues, although bacteria often existed. In addition, experimental infection with the ciliates could establish the positive infections, illustrating the ciliate to be the causative pathogen of the scuticociliatosis.

Topic Category 生物農學 > 農業
生物農學 > 森林
生物農學 > 畜牧
生物農學 > 漁業