防栉孔扇贝养成死亡的新方法--栉孔扇贝与虾夷扇贝混养试验

本文研究了栉孔扇贝和虾夷扇贝混养后的成活率和经济效益，结果表明：混养后的栉孔扇贝的成活率明显提高，比单养栉孔扇贝提高了62％，并取得了明显经济效益。     

扇贝外寄生车轮虫（Trichodina jadranica Raabe，1958）的形态学研究 （原生动物：纤毛门：缘毛目）

采用Ｗｉｌｂｅｒｔ蛋白银法及Ｃｈａｔｔｏｎ—Ｌｗｏｆｆ银浸法对一种附生于栉孔扇贝鳃丝上的寄生车轮虫进行了光镜水平下的研究。依据其形态学和纤毛图式特征，该种被鉴定为ＴｒｉｃｈｏｄｉｎａｊａｄｒａｎｉｃａＲａａｂｅ，１９５８．此为我国新记录，同时也是第一例有关外寄生于扇贝鳃表纤毛虫原生动物的报道。     

4种养殖扇贝的群体遗传多样性及特异性AFLP标记研究

应用AFLP技术对我国4种主要养殖扇贝进行了遗传分析.虾夷扇贝、海湾扇贝、华贵栉孔扇贝、栉孔扇贝4种养殖扇贝群体中,种内遗传相似度依次分别为0.841 5,0.786 3,0.719 0和0.673 1,香侬氏指数分别为43.52,58.87,80.16和92.83,栉孔扇贝和华贵栉孔扇贝的遗传多样性水平明显高于海湾扇贝和虾夷扇贝;AFLP标记共享位点分布表明,在4种扇贝中栉孔扇贝与华贵栉孔扇贝之间的共享位点最多,同时4种扇贝的种间遗传相似度也以栉孔扇贝和华贵栉孔扇贝之间为最高(0.769 5),海湾扇贝和虾夷扇贝之间为最低(0.662 6),揭示所研究的几种扇贝中栉孔扇贝和华贵栉孔扇贝的遗传关系最近(遗传距离为0.262 1);找到了21个种内特异性AFLP标记和种间共享标记,可用于种质鉴定和分子辅助分类.     

栉孔扇贝大量死亡的流行病学调查研究

2001~2003年,对养殖的栉孔扇贝进行了较系统地流行病学调查研究.以栉孔扇贝养殖集中海区长岛县亚美扇贝养殖场为定点调查和样品采集点.调查内容主要包括栉孔扇贝各养殖期的死亡率和可疑病原生物检测,同时对pH、溶解氧、温度、盐度等环境理化因子进行连续监测.调查结果显示:栉孔扇贝在养殖初期幼贝阶段死亡率较低,随后死亡率逐渐升高,至8月24日月死亡率达最高点71%.9月份以后死亡率开始下降.至10月份累积死亡率达90%以上.对环境理化因子的调查显示,pH、溶解氧、盐度的变化幅度不大,与扇贝死亡率无明显相关性;温度变化与死亡率似有一定的相关性,即高温(月平均23℃以上)可能是养殖栉孔扇贝重要的环境胁迫因子.通过对可疑致病性生物因子的调查研究及病理学观察表明,栉孔扇贝在养殖过程中可感染多种微生物,其中原核微生物类立克次体(RLO)在养殖过程各生长阶段均可检出,其感染率和感染强度与扇贝死亡率呈现一致的趋势.在病原病理检测中,发现RLO的大量感染与组织细胞严重病理损伤密切相关.在病原生物检测过程中,除RLO以外还发现有类枝原体原核生物(MLO)和类病毒(VLP)寄生.RLO的人工感染实验结果说明RLO是栉孔扇贝重要的病原菌.结合感染率和死亡率、感染强度和组织病理学的相关性以及感染实验的结果分析,认为类立克次体(RLO)可能是栉孔扇贝养殖过程中大量死亡的主要致病因子.     

山东沿岸夏季栉孔扇贝大规模死亡原因分析

在对夏季高温期山东沿海栉孔扇贝大规模死亡现状调查的基础上,从山东沿岸栉孔扇贝养殖业发展的历史,生态,环境和种质等方面分析了栉孔扇贝大规模死亡的原因,认为大规模死亡的根本原因是长期订养殖导致养殖环境的老化或恶化及栉孔扇贝抗逆能力下降,而在夏季高温期,海区饵料明显不足,栉孔扇贝本身消耗增大,养殖水体自身污染加剧及病原体大量滋生更为直接的原因。     

栉孔扇贝秋季半人工采苗技术

随着扇贝养殖业的发展,扇贝人工育苗技术和春季半人工采苗技术都有了很大改进和提高。但对栉孔扇贝的秋季半人工采苗技术却很少研究。为解决苗源不足问题,1986年我们在荣成桑沟湾海区进行了栉孔扇贝秋季半人工采苗试验,并取得了显著效果。     

栉孔扇贝养殖病害原因及其防治措施

栉孔扇贝筏式养殖在山东省长岛已有21年的历史。1983～1993年连续出现扇贝大量死亡的现象,累计2万多亩受灾,造成经济损失达3亿多元。因此,迅速查明栉孔扇贝死亡的原因便成为扇贝养殖业的重要课题。 1 栉孔扇贝死亡原因 1.高温期进行分苗,使贝苗受到高温刺激,是引起扇贝大量死亡的重要原因之一。 2.由于栉孔扇贝在分苗养成初期挂的水层偏浅,而在牡蛎繁殖高峰期内扇贝放养的水层又没有下调到深水层来避开牡蛎苗的附着水     

中国栉孔扇贝养殖和育种的回顾与展望

栉孔扇贝作为一种双壳贝类，其营养和经济价值较高，在中国海水养殖业中占有重要地位。自20世纪50年代开始，栉孔扇贝养殖产业先后经历了自然采苗、半人工采苗、人工育苗、提纯复壮和新品种培育等过程，逐渐成为中国北方主要的浅海浮筏养殖品种。本文综述了中国栉孔扇贝养殖产业的发展历程，简要总结其养殖和育种过程中存在的问题，并对其今后的发展进行展望。     

专家为扇贝养殖持续发展开出处方

自1997年以来,我国北方沿海栉孔扇贝相继发生大面积死亡事件。据了解,仅山东省经济损失就近40亿元,尤其是视栉孔扇贝为衣食父母的长岛县,1997年和1998年两年直接经济损失近10亿元,严重影响了长岛县人民的切身利益。栉孔扇贝的大量死亡,也对整个山东省沿海扇贝养殖业可持续发展提出了新的课题。在     

栉孔扇贝大规模死亡的原因探讨

于１９９８年７－９月,在发生贝类大规模死亡的山东工岛县和烟台四十里湾养殖区,选取濒死的栉孔扇贝,通过组织病理分析和电镜观察,发现大量寄生原核生物－－衣原体样原核生物和类立克次氏体。病理学研究表明,寄生原核生物造成栉孔扇贝组织细胞严重病变,可能是引起栉孔扇贝大规模死亡的重要原因。     

Does bivalve mucus favour the growth of their main food source,microalgae?

Bivalves, by releasing inorganic nutrients, can stimulate the growth of the primary producers on which they feed. Dissolved excretion and mineralization of biodeposits (pseudofaeces and faeces), two indirect processes related to their feeding activity, have already been identified. This study investigated whether microalgal growth is also dependent on the mucus secreted by bivalves and rejected with their biodeposits. An experimental study based on algal growth tests was conducted to determine whether the mucus coating the pseudofaeces and faeces of the oyster Crassostrea gigas (Thunberg) could stimulate the growth of nine marine microalgae: a Prasinophyceae [Tetraselmis suecica (Butcher)] and eight Diatomophyceae [Amphora sp. (Ehrenberg), Chaetoceros sp. (Ehrenberg), Entomoneis alata (Ehrenberg), Haslea ostrearia (Simonsen), Nitzschia acicularis (Wm Smith), N. closterium (Wm Smith), N. gandersheimiensis (Krasske) and Skeletonema costatum (Cleve)]. Oysters were fed only inorganic particles at a concentration well above the threshold of pseudofaeces production. A fraction of pseudofaeces and faeces was then inoculated into glass tubes containing a single algal species. Algal growth tests showed that mucus stimulated the growth of four of the nine species studied: Chaetoceros sp., H. ostrearia, N. gandersheimiensis and T. suecica. The strongest responses were observed with H. ostrearia and Chaetoceros sp., for which mean algal biomass was significantly higher with mucus originating from pseudofaeces than faeces. Monitoring of the release of dissolved components from mucus showed significant enrichment in inorganic phosporus. The use of an antibiotic treatment suggested that this dissolved component is released by simple solubilization rather than by bacterial breakdown.     

紫扇贝与海湾扇贝种间杂交的研究

为推动中国扇贝养殖业的进一步发展,作者于2008年从秘鲁引进了紫扇贝(Argopecten purpuratus),尝试将紫扇贝与海湾扇贝(Argopecten purpuratus)进行杂交,以期培育出具有优势性状的杂交子代.利用引进的紫扇贝与海湾扇贝进行种间杂交,培育出紫扇贝(雌)×海湾扇贝(雄)杂交扇贝.实验证明紫扇贝的卵子与海湾扇贝的精子可正常受精,受精卵发育正常.杂交扇贝的生长速度在幼虫阶段和成体阶段均快于海湾扇贝.至收获时,杂交贝比海湾扇贝平均壳高、壳长和壳宽分别大27.3%,25.2%和19.3%,体质量增加107.0%,杂种优势明显.     

污损生物对大亚湾养殖扇贝的食物吸收及营养盐排泄的影响

污损生物是影响贝类养殖业生产效率的重要因素。附着在养殖生物贝壳上的污损生物影响养殖生物的生长和存活。大部分污损生物是滤食性捕食者,这些污损生物附着在养殖生物贝壳上竞争食物与空间导致贝类生长速度减慢。本实验主要研究有污损生物附着的扇贝及没有污损附着的扇贝在摄食及排泄上的差异,用以说明污损生物对养殖生物摄食及排泄的影响。本研究对chlorophylla和TPM的吸收速率进行了测定,对NH4-N,NO2-N,NO3-N,PO4-P的排泄速率进行了测定,对摄食的浮游植物进行了种类鉴定。研究结果表明,有污损生物附着的扇贝及没有污损附着的扇贝在对浮游植物及颗粒物的吸收速率上存在明显差异（P〈0．001）。在氨及亚硝态氮排泄速率上也存在明显差异（P〈0．001）。两者吸收NO3-N,且吸收速率无差异。通过对摄食的浮游植物种类的鉴定表明,有污损生物附着的扇贝摄食的浮游植物种类要高于没有污损附着的扇贝,且摄食种类有重叠。对同一类的某些浮游植物,有污损生物附着的扇贝的摄食要高于干净扇贝。本研究结果表明,污损生物对浮游植物的摄食及水中氨氮浓度的提高贡献很大,与养殖生物之间存在食物竞争。     

鲈鱼的鳃寄生车轮虫病及扫描电镜观察

报道鲈鱼的鳃寄生车轮虫病及病理组织的扫描电镜观察。病原鉴定为 :直钩车轮虫、杜氏车轮虫、日本车轮虫、劳牧小车轮虫及简单两分虫 5种车轮虫科纤毛虫 ,其中数量上占优势的为直钩车轮虫。扫描电镜观察结果表明 ,鳃寄生车轮虫可对宿主的上皮组织产生明显的机械性损伤并造成鳃丝粘液分泌增多及炎症反应。文中就海水养殖鱼类及野生鱼类由车轮虫寄生造成的危害及防治途径做了探讨。     

四种贝类和鱼类外寄生车轮虫的国内新纪录

车轮虫是一类主要寄生于贝类和鱼类体表的缘毛类纤毛虫原生动物。本文对分别寄生于海洋贝类－－虾夷扇贝Mizuhopecten yessoensis,半咸水鱼类－－鲻鱼Mugil cephalus和双色鳗鲡Anguilla bicolor bicolor,以及淡水鱼类－－光唇鱼Acrossocheilus fasciatus鳃表和体表的虾夷扇贝车轮虫Trichodina pectenis,亚卓车轮虫T.jadranica,急尖车轮虫T.acuta和喙状车轮虫T.rostrata,进行了详细的分类学研究。本文第一次报道了虾夷扇贝车轮虫的活体和蛋白银染色后特征,该虫体也是国内新记录种。其它三个车轮虫物种感染的鱼类,均属新纪录宿主。同时,也报道了这四种车轮虫对宿主的感染率和感染强度。     

Relationships of growth and mortality to enzymatic activity,and the relative mRNA expression of cultured scallops Patinopecten yessoensis in the Yellow Sea,China

The bottom aquaculture of yesso scallop (Patinopecten yessoensis) has developed rapidly in the north of Yellow Sea, China, but not without accompanying productivity problems. We, therefore, conducted field surveys to investigate factors related to growth and mortality rates of bottom-cultured scallops after release. Specifically, we focused on the effects of total antioxidant capacity (TAOC) and three key enzymes involved in antioxidant and metabolic function:glutamic pyruvic transaminase (GPT), lactic dehydrogenase (LDH), and superoxide dismutase (SOD). Across summer and winter, we also measured the relative mRNA expression of GPT and SOD to understand their seasonal variation in the scallops, along with how such variation correlated to growth and mortality. Results show that bottom cultured scallops experienced mass mortality during the first six months post-release. During winter (December), scallops grew more rapidly and suffered less mortality than in summer (August). The observed lower performance probably resulted from less advantageous environmental factors during the summer seasons, such as high temperature and low dissolved oxygen. These environmental stressors enhance protein consumption while decreasing energetic resources in scallops. Furthermore, scallops in summer exhibited high antioxidant levels that probably competed for energy with process integral to growth and survival. These negative factors combined to elevate mortality rates. In conclusion, we provided evidence suggesting correlations between metabolic/antioxidant activity and growth and mortality of bottom-cultured yesso scallops. These correlations implied us an accurate method to estimate the performance of bottom culture system. Suggestions about innovative aquaculture techniques were also discussed in the study. Our results might provide a possible guideline to the improvement of bottom culture techniques for this commercially valuable seafood species.     

栉孔扇贝的食料分析

栉孔扇贝的食料以硅藻为主,作者在调查海区中共检查出硅藻79种,隶属于37属,扇贝胃含物中共检出59种,隶属于28属 栉孔扇贝易摄食的主要种类有舟形藻、圆筛藻、骨条藻、曲舟藻和金藻,选择指数较高;兼食一些绿藻、桡足类、无脊椎动物卵和幼虫及有机碎屑 栉孔扇贝对角毛藻、根管藻、楔形藻、甲藻类及纤毛虫类选择指数较小,其主要原因是这些生物有长的角毛、尖而硬的棘和刺,不易被鳃过滤和摄食。栉孔扇贝的食料随季节、海区的不同,食料的组成以及对食料的选择指数都有不同的变化。同一季节不同日期其食料组成也随着海区浮游生物的变动而变化 不同大小的扇贝在同一海区中其食料组成是类似的,无明显差异     

Discriminating zooplankton assemblages in neritic and oceanic waters: a case for the northeast coast of India, Bay of Bengal

Zooplankton species distribution and abundance data at 17 locations in the inshore (10-30 m), shelf (50-200 m) and oceanic (2,500-2,800 m) regions off northeast India (Bay of Bengal) during January 1999-April 2001 revealed 112 taxa represented by 30 divergent groups. Copepods (58 species) dominated (87%) the population numerically. In general zooplankton diversity (Margalef richness d, Shannon-Wiener H', Pielou's evenness J') increased in the direction of the open sea relative to coastal locations with a concomitant decrease both in abundance (ind m(-3)) and biomass (dry mass m(-3)). Based on multivariate analyses, it was possible to distinguish the zooplankton community into different assemblages according to their location (e.g., inshore, shelf, oceanic) and seasonality. While Acrocalanus sp., Oithona sp., Corycaeus danae, Euterpina acutifrons, Paracalanus sp., and Acartia sp. were found characterizing the coastal locations, Oncaea venusta was the discriminating species for shelf waters. In oceanic areas, there was a clear dominance of Labidocera sp., Candacia sp., Euchaeta rimana, Centropages calaninus, Copilia mirabilis and Corycella gibbula. The investigations revealed that changes in zooplankton community structure across water bodies could be associated with differing salinity. During November 1999 (post-monsoon), when salinity in the coastal waters was relatively low (26-28.9 PSU), the zooplankton community consisted of mainly Acrocalanus sp., Salpa, Corycaeus danae, Oikopleura sp., Acartia sp., Evadne tergestina, and Creseis sp. In January 2000 (salinity 32.4-34.1), additionally Corycella gibbula, Labidocera sp., Centropages sp., Microsetella sp., Euterpina acutifrons, Canthocalanus pauper, and Oncaea venusta represented the population discriminating the assemblage from others. In May 2000 (pre-monsoon) when salinity was highest (34.7-35.3), Oithona sp., Paracalanus sp., and Acrocalanus gibber were found important. Chaetognaths formed a distinct group during this period. Results presented during this investigation are considered significant since no previous studies exist for this locale drawing comparisons of the kind made during this study between coastal and oceanic situations.     

Relationship between shell weight and cadmium content in whole digestive gland of the Japanese scallop Patinopecten yessoensis (Jay)

Seasonal and age-specific variations of cadmium (Cd) concentration in the digestive gland were investigated in the Japanese scallop Patinopecten yessoensis from Peter the Great Bay, Sea of Japan, with different degrees of Cd pollution. The seasonal changes in Cd concentrations of the digestive gland were inversely proportional to the dry weight of the gland. Concentrations of Cd and total Cd content (mug Cd per organ) increased with age (age-specific) to the same extent in contaminated and uncontaminated areas. There was also a strong positive correlation between Cd content in the whole digestive gland and shell weight and it is proposed that this relationship can be used as a new criterion for comparative evaluation of Cd levels in scallops from different areas We hypothesize that Cd is uptaken into scallops in proportion to the amount of calcium that absorbed through ion channels, and in addition, Cd in the digestive gland is in immobile forms (e.g. metal-rich granules) that accumulate with age. Moderate environmental pollution has no effect on the relationship between Cd content and shell size and the observed decrease in growth performance of the scallops from polluted areas may be due to other factors.