Hatchery broodstock conditioning of the blue mussel <Emphasis Type="Italic">Mytilus edulis</Emphasis> (Linnaeus 1758). Part I. Impact of different micro-algae mixtures on broodstock performance

Blue mussel (Mytilus edulis) broodstock collected from the Irish Sea during wintertime (November) was conditioned with three different microalgae diets. Positive flagellates (PF) treatment consisted of Pavlova lutherii, Isochrysis galbana (T-Iso), and Chaetoceros calcitrans (1:1:1). Positive diatoms (PD) treatment consisted of Pavlova lutherii, Chaetoceros calcitrans, and Skeletonema costatum (1:1:1). Broodstock animals in the PF and PD treatments were fed a total of 2.4 × 10¹¹ algae cells per day. Animals in the negative flagellates (NF) treatment received only 1/8th of the total amount of algae of the PF diet. The conditioning diets had an impact on spawning success and broodstock fecundity but not on hatching rate, which was similar in all three groups. The best results were obtained with the PD diet where 84% of the conditioned animals spawned and females released 5.0 × 10⁶ eggs on average. Animals belonging to the PF and NF treatments released, on average, only 3.6 × 10⁶ and 1.6 × 10⁶ eggs, respectively. Although the amounts of algae provided to the broodstock animals had no effect on the hatching rate, the D-larvae resulting from the NF treatment were smaller in size than the larvae from the other treatments. Biochemical analysis of the different broodstock groups at the end of the experiment revealed higher carbohydrate levels in group NF than in PF and PD, supporting the theory that gametogenesis is mainly supported by the energy from the glycogen reserves. As far as we are aware this is the first study describing hatchery broodstock conditioning of blue mussels under fully controlled conditions.     

贝藻处理工厂化养殖废水的研究

研究了常见大型藻类对氮、磷营养盐的去除效果和贝类对悬浮颗粒物的去除效果。结果表明,石莼和海带在同样的实验条件下吸附氮、磷营养盐的效果明显高于鼠尾藻和马尾藻,密度2g/L的石莼和7.52g/L的海带是较好的养殖密度。与扇贝和文蛤比较,牡蛎具有较高的去除悬浮颗粒物的效率,可以在24h内除去养殖废水中93%的悬浮颗粒物。在20L养殖废水中投放1000g牡蛎和40g石莼组成的净化养殖废水的生物滤器对营养盐和悬浮颗粒物具有最好的去除效果,其去除效率分别为PO4P67.8%、NO2N60.2%、NH4N55.8%、NO3N59.0%和SPM82.5%。在20L养殖废水中投放1000g牡蛎和150g海带组成的生物滤器对营养盐和悬浮颗粒物的去除效果较好,其去除效率分别为PO4P62.6%,NO2N55.7%,NH4N46.0%,NO3N56.6%和SPM84.5%。     

主要经济双壳贝类性别分化的分子机制概述

本文简要概述了主要经济双壳贝类性别分化分子机制研究进展,介绍国内外研究性别分化和性别决定的代表性双壳贝类物种及主要研究成果,主要涉及牡蛎科(Ostreidae)、扇贝科(Pectinidae)、珍珠贝科(Pteriidae)等常见的经济物种,分子层面涵盖了核酸、蛋白质和激素等,通过综述这些物种相关研究的现状,展望双壳贝类性别分化研究的发展趋势,以期加深对双壳贝类性别分化和性腺发育的认识,为解析虾夷扇贝(Patinopecten yessoensis)及其他双壳贝类性别分化分子机制研究理清思路。     

凸加夫蛤的藻类滤食能力及其对海水氮磷含量的影响

研究热带亚热带双壳贝类凸加夫蛤(Gafrarium tumidum)对富营养化水体中藻类的滤食能力及其对海水氮磷含量的影响。结果表明,凸加夫蛤能有效地清除水体中的叶绿素a,在海水N、P含量分别为0.5 mg/L和0.04 mg/L,初始藻密度为5×106 cell/L的情况下,72 h就能起到显著效果,144 h(6 d)之后对藻类密度的控制达到理想的效果。当贝密度在1~2 kg/m3范围内时效果最佳,且不会引起水体中N、P含量的增加。因此,凸加夫蛤是热带海域控制藻类密度、改善水质和预防赤潮的经济双壳贝类之一。     

国际双壳贝类产业动态

2013年,贝类对环境变化的脆弱性的诸多迹象已经显而易见。法国牡蛎养殖业再次经历了致死性细菌的严重打击,成体牡蛎因而大量死亡。为了应对全球气候变暖对贝类的影响,来自欧盟几个成员国的研究人员共同开展了一项名为"CACHE(Calcium in a Changing Environment:变化环境中的钙)"的科研项目,项目获资助金额高达数百万欧元。就市场而言,贝类国际贸易依然相当强劲。中国的贝类进口一直都在增加,除贻贝外,美国进口的其他贝类数量也在持续增长,而欧洲的贝类进口和消费则保持着相对稳定的态势。全球范围内,对环境可持续实践和有机产品的认证方兴未艾。     

Effect of geographic origin, temperature and timing of broodstock collection on conditioning, spawning success and larval viability of Ruditapes decussatus (Linné, 1758)

Culture of Ruditapes decussatus is clearly limited by the availability of seed, as this production proceeds almost exclusively from natural recruitment. Artificial spawning and larval rearing programs could provide an alternative source of spat. This study was designed to evaluate the effect of different conditioning temperatures on the broodstock maturation, spawning success and larval viability of two geographically (north and south of the Iberian Peninsula) distinct populations of European clam (R. decussatus) collected at different periods of the year in order to create “optimal” artificial spawning and larval rearing programs. Two batches of clams from each population were collected in October and February, and conditioned at 18 ± 1°C, 20 ± 1°C and 22 ± 1°C. Of the three variables analysed the timing of broodstock collection was the most determining factor for gametogenic development, spawning and larval rearing. Geographic origin and conditioning temperature also greatly affected the spawning. The results also showed that the February conditioning was more effective than October and that the best conditioning temperatures were 20 ± 1°C and 22 ± 1°C for the northern and southern populations, respectively. These results suggest that the efficient conditioning temperature for each population of the same species is related to the seasonal temperature regime from their geographic origin. Larval viability and growth performance seemed to be independent of the broodstock conditioning.     

青岛地区贝类产品中诺如病毒的感染和流行初探

从2006年1月至2007年1月,在青岛市内3区5个主要水产品批发市场连续采集贝类样品,其中太平洋牡蛎Crassostreagi gas 208个、毛蚶Scapharca subcrenata 169个、杂色蛤Venerupis variegata 169个,采用RT—PCR方法检测诺如病毒（Novoviruses,NV）的感染,旨在为贝类食品的安全监控提供基础数据资料。研究结果表明,太平洋牡蛎和毛蚶样品中NV检出率分别为10．1％和5．3％,而杂色蛤未检出,NV流行的季节主要是11月至次年3月,感染部位主要分布于贝类的消化道。     

The culture of the southern bay scallop in Tampa Bay, an urban Florida estuary

Bay scallop, Argopecten irradians concentricus (Say), stocks were collected from a Homosassa (Florida) population in 1991 and were kept in seawater from Bayboro Harbor on Tampa Bay, an urban Florida estuary. They were fed with Isochrysis galbana and Tetraselmis sp. Spawning was allowed to occur after the scallops became ripe. The hatching rate of the F1 eggs to D-shaped larvae was 72%. Settlement and metamorphosis began 11 days after fertilization. When spat reached a shell height of 0.8 mm in the laboratory, they were placed with substrates into 300 and 800 m mesh bags, and later in lantern nets, suspended from a dock in Bayboro Harbor. The F1 scallops successfully survived to gonad maturity in the fall of 1992, with mean (sd) shell height of 49.8 (4.0) mm on 6 September 1992. The scallops experienced heavy mortality during the summer, partially as a result of heavy fouling. From early August to October of 1992, F1 scallops grown in Bayboro Harbor were successfully spawned in the laboratory. Growth and survival of the F2 scallops were comparable to those of the F1 scallops. Results have shown that bay scallops can complete an entire life cycle in an urban estuary such as Tampa Bay, and a hatchery for bay scallops on the estuary can assist in the restoration of the population. Fouling represents a possible severe limitation and alternatives to caging for grow-out should be considered.     

海洋双壳贝类滤水率测定方法概述

对双壳贝类滤水率测定方法及注意事项进行了较为全面的阐述,对国内该方面的研究存在的问题进行了探讨。