海贝柱自动晾晒设备设计

针对当前传统人工晾晒海贝柱效率低下、容易造成污染等问题。设计了海贝柱自动晾晒机械,采用阶梯式晾晒生产线对湿海贝柱分级晾晒,多条晾晒生产线分时、高效的工作,机器上方设有遮板以保证晾晒作业不被污染而且不受天气条件的影响。整机采用stm32单片机、传感器等技术实现自动化作业,机器控制系统监测到生产线发生故障或海贝柱出现堆积时会立即停止工作以便于检查故障、减少损失。试验结果表明:机械晾晒不会造成海贝柱内的营养成分的流失,机械晾晒海贝柱的干基含水率达到30%仅需12h,机械晾晒海贝柱能节省大量的干燥时间,显著的提高了晾晒效率,避免了人工晾晒过程导致的二次污染和损失。该研究为海贝柱自动晾晒机械的研制提供了技术参考。     

扇贝加工废弃物蛋白酶解及其酶解产物分子量分布的研究

对用复合酶酶解扇贝加工废弃物制备水解蛋白的工艺进行了研究,通过正交试验方法确定了用两种复合酶酶解的最适水解条件。结果表明,用枯草杆菌中性蛋白酶和风味酶复合酶酶解的最佳酶解参数为:加酶量比为2∶1,温度为65℃,pH为7.0,时间为5 h,水解液氨基酸态氮含量为50.3%,蛋白质水解度为95.5%。用木瓜蛋白酶和风味酶复合酶酶解的最佳酶解参数为:加酶量比为2∶1,温度为65℃,pH为7.0,时间为5 h,水解液氨基酸态氮含量为43.2%,蛋白质水解度为85.0%。用SephadexG-15葡聚糖凝胶柱层析法对水解产物的分析结果表明,两种混合酶的酶解产物为蛋白肽和游离氨基酸,其相对分子质量均集中分布在585和150左右。     

Culture of mantle epithelial cells expressing shell matrix proteins from scallop Patinopecten yessoensis

ABSTRACT:   In molluscs, mantle epithelial cells secrete organic matrix proteins to form shells. In this study, we established a culture of mantle epithelial cells by using the mantle pallial layer of scallops. We aimed to identify the mantle epithelial cells expressing scallop shell matrix proteins and establish a culture system of epithelial cells. After the mantle pallial layer was carefully isolated from the mantle tissue, explant culture was performed at 4°C. Most cells that migrated from the explant tissue were round cells. Most of the adhered cells retained round morphology, while some of the cells adhered to the dish and showed morphology similar to that of epithelial-like and fibroblast-like cells. When the cultured cells were immunostained with a polyclonal antibody against the shell matrix protein, the antibody recognized many of the adhered cells. An estimation of the number of epithelial cells revealed that approximately 70% of the adhered cells were epithelial cells. This is the first report to describe epithelial cells in cultured mantle cells, which express shell matrix proteins. This culture system may be a useful method for characterization of the mantle epithelial cells.     

Efficacy of Netminder® silicone release coating for biofouling reduction in bay scallop grow‐out and comparative effects on scallop survival,growth and reproduction

Netminder^®, a water‐based silicone barrier release coating, was highly effective in reducing biofouling of lantern nets during grow‐out/overwintering of bay scallops, Argopecten irradians irradians, in a large‐scale restoration programme in New York, USA. Compared with untreated nets, scallops held in Netminder^®‐coated nets experienced reduced survival after 8 months, probably due to higher loads of epibionts on their shells. However, this was countered by higher reproductive and overall condition of scallops in treated vs. untreated nets; there were no consistent differences in shell growth in different net treatments. Although further testing is recommended under a wider range of conditions, we conclude that for the purposes of our scallop restoration work, coating nets with Netminder^® would eliminate the need for a gear change in spring, thus reducing labour costs; the coating process should be refined so that Velcro closures of nets do not become sealed shut.     

Comparison of early life history stages of the bay scallop, Argopecten irradians: Effects of microalgal diets on growth and biochemical composition

The culture of bay scallops, Argopecten irradians, is limited by a reliable and affordable supply of spat and the ability to ensure that animals attain market size within a single growing season. The main goals of our study were thus: (1) to develop growth-optimizing algal diets for implementation in hatcheries, and (2) to identify and compare bay scallop postlarval and juvenile dietary requirements, especially of lipids and fatty acids, which if met may enhance production. Nutritional needs of postlarval bay scallops (present study) are compared with those of sea scallops, Placopecten magellanicus, offered the same diets in a previous companion study. To this end, postlarval (initial shell height, SH = 240 μm) and juvenile (initial SH = 10 mm) bay scallops were offered 6–7 microalgal diet combinations at 20 °C, for 3 weeks. A similar growth ranking among diets was observed between the two developmental stages. A combination diet of Pavlova sp. (CCMP 459) and Chaetoceros muelleri was far superior to any other diet tested, yielding growth rates of 58 and 357 μm day^− 1 which were 65% and 25% higher than the next highest performing diet of Tetraselmis striata/C. muelleri in postlarvae and juveniles, respectively. The T. striata/C. muelleri diet, which is limited in the n-3 fatty acid docosahexaenoic acid (DHA), yielded very poor growth of sea scallop postlarvae in a prior study, indicating that bay scallops may have less stringent requirements for DHA than sea scallops. The Pav 459/C. muelleri diet, which also supported the highest growth of sea scallop postlarvae, is characterized by elevated levels of the n-6 fatty acids, arachidonic (AA) in C. muelleri and 4,7,10,13,16-docosapentaenoic (DPA) in Pav 459. The two diets deficient in AA and n-6 DPA, Pavlova lutheri/Thalassiosira weissflogii and P. lutheri/Fragilaria familica, yielded the lowest growth rates in both bay scallop postlarvae and juveniles. Tissue enrichment of these two fatty acids relative to the diet, as well as overall enrichment in ∑n-6 fatty acids was observed across developmental stages and dietary treatments. A similar pattern has previously been observed in sea scallop postlarvae, suggesting a dietary requirement for n-6 fatty acids in pectinids that has often been overlooked in the past.     

Recruitment of catarina scallop (Argopecten ventricosus) larvae on artificial collectors off the NE coast of the Gulf of California

We evaluated recruitment of larvae of catarina scallop, Argopecten ventricosus, in the area of Puerto Peñasco, NE Gulf of California. We moored artificial collectors in six sites from June 2007 to August 2008 and replaced them every 2 months. We used monthly (July 2002–September 2011) sea surface temperature (SST, °C) and surface chlorophyll‐a concentration (SSChl, mg m^?3) Aqua/MODIS satellite data to describe seasonal environmental behaviour study area. Also, we recorded bottom temperature at each site every 4 h, and every 2 months measured sea surface salinity, temperature and dissolved oxygen. We used a repeated measures anova to evaluate differences in the number of recruited spat between main factors, and analysed the presence of multimodal spat shell size frequency distributions. Overall, spat recruitment was negatively correlated with seawater temperature and showed higher spat recruitment abundances throughout winter, which is the season with the highest surface chlorophyll a concentration. We estimated multimodal shell size frequency distributions characterized by more than one modal size. The natural collection of A. ventricosus spat on artificial collectors in the area can be successfully performed over a protracted period (November–December to May–June). Our results extend the area where collection of A. ventricosus spat can be successful.     

Effect of air exposure on scallop behaviour, and the implications for subsequent survival in culture

Scallop spat produced for continued culture normally requiretransportation between sites, and the associated stresses may causemortalities. In the present experiment, scallops of 40–55 mm shell heightwere emersed in air for time intervals up to 24 h and their behaviourexamined once re-immersed. Scallops were placed upside-down and thenumber of movements and the cumulative numbers righting in 5 min timeblocks were recorded. The greatest frequency for all behaviouralresponses was found at 15–17 °C in August. Responses were reducedin November and June (9–11 °C) and least at 5 °C in January.All effects of treatment, temperatures and season, and increases in airexposure were significantly different. Following the treatments, mortalitiesafter 10 days in culture was about 10–30% for scallops emersed for 18 and24 h in August and June. Scallops did not show significantly differentbehaviour whether they were emersed upright or inverted. However,scallops emersed at 15 °C had fewer responses than scallops held at <10 °C, so chilling during transport may prolong scallop vitality. Theresults suggest that air exposure >12 h should be avoided. At temperatures>9 °C, behavioural responses may be a simple and effective method toassess vitality which can assist in the management of scallop culture.     

虾夷扇贝捕捞网具的改进及应用效果

该文针对目前扇贝捕捞网具捕捞效率低及耗能大等问题,通过对獐子岛集团股份有限公司3 a龄虾夷扇贝(Patinopecten yessoensis)底播养殖海域海底状况与网具捕捞效果的调研,提出了虾夷扇贝捕捞网具的改进措施,并在辽长渔养15021号扇贝采捕船上进行了2个阶段海上生产对比试验,得出以下结论：第一阶段在原生产网具的基础上,安装扭簧式弹性拨贝齿及增大网目等措施,在拖网航速为4kn时,改造后网具单网平均捕捞量较生产网具提高了36.5%,扇贝破损量降低了49.4%,泥沙量降低了21.9%,单位捕捞耗油量降低了27.8%。第二阶段改造网具在第一阶段的基础上,增大网口扫海面积,并且将网身改为"宽口窄尾"结构,添加一道网口链及辅网衣,并加装主网拐雪橇板、拐前拨贝齿及网底托架小车,在拖网航速为4kn时,单网捕捞量较第一阶段改造网具提高了102%,扇贝碎贝量降低了161%,泥沙量降低了209%,单位捕捞耗油量降低了24.6%;而较原生产网具单网平均捕捞量提高了200%,扇贝破损量降低了236%,泥沙量降低了296%,单位捕捞耗油量降低了45.6%。由此说明新型虾夷扇贝捕捞网具具有高效、节能和低生态等特点,推广应用前景广阔。     

虾夷扇贝家系群体遗传结构及其微卫星标记与经济性状相关性的分析研究

为了有效利用微卫星技术分析虾夷扇贝的群体遗传结构并筛选与虾夷扇贝生长相关的标记。采用19个多态性微卫星分子标记对虾夷扇贝一个家系群体进行了遗传多样性分析。结果显示：19个微卫星位点共获得60个等位基因,每个位点的等位基因数(Na)为2~4个,等位基因片段大小为113~312 bp,平均等位基因数为3.26个,平均有效等位基因数(Ne)为3.0175个,观测杂合度(Ho)平均值为0.2952,期望杂合度(He)的平均值为0.6352,平均多态信息含量(PIC)值为0.5671。经卡方Hardy-Weinberg检验(P<0.01)显示多于半数的位点都发生了偏离。运用SPSS 16.0对微卫星标记与虾夷扇贝生长性状的相关性进行分析,结果表明：DQ679223与壳宽显著相关,EF056526与体重、壳长、壳高、壳宽显著相关,DQ221720与体重、壳高、壳宽显著相关,FJ262409与体重显著相关。研究结果表明：虾夷扇贝的群体遗传多样性水平较高,有较高的遗传改良潜力,可以利用筛选的与虾夷扇贝生长相关的标记进行辅助育种,提高育种效率。