不同运输条件对合浦珠母贝稚贝存活比较

比较运输方式及环境温度对合浦珠母贝稚贝运输中的存活影响,从而为稚贝运输过程中的运输方式、环境温度及运输时间的把握提供借鉴和参考。以3月龄稚贝为实验材料,运用无水干露、加水淹没及包装充氧等3种方式,分别在环境温度为5、13、21和29℃下模拟运输。每隔3 h从每组运输条件下取出1组实验贝,转移到正常养殖环境下暂养恢复,经48 h后统计其存活率。对运输时间与存活率之间进行非线性参数曲线拟合,计算每组运输条件下的致死时间(T_0)、半致死时间(T_(0.5))及全致死时间(T_1);运用双因素方差分析,Duncan氏方法比较3种运输方式及4种环境温度间的均值。结果显示:包装充氧优于其他两种运输方式,而加水淹没又优于无水干露;温度为13℃和21℃时优于其他2个环境温度,环境温度为17.60～20.05℃是稚贝运输的最佳温度。     

东亚钳蝎疾病与天敌的防治

本文介绍了东亚钳蝎在人工养殖条件下 ,一些疾病与天敌发生的原因、临床症状及防治方法。     

马氏珠母贝肉的营养成分及其游离氨基酸组成

对马氏珠母贝肉的营养成分及游离氨基酸组成进行了较系统的食品化学特性研究，结果表明：马氏珠母贝含粗蛋白７４．９％（干基），蛋白质的氨基酸组成中，富含Ｇｌｕ（２．２１％）、Ａｓｐ（１．４５）、Ｇｌｙ（１．０１％）等呈味氨基酸；蛋白质营养价高，氨基酸价为８２，第一限制氨基酸是含硫氨基酸（１９７３年（ＦＡＯ／ＷＨＯ标准）；无机盐含量丰富，尤其是微量元素Ｚｎ和Ｓｅ；游离氨基酸中，牛磺酸含量最高达１．３８％，     

珠母贝糖胺聚糖的纯化及其化学性质

珠母贝糖胺聚糖粗制品经吸附、等电点沉淀、醇沉、溴化十六浣基三甲铵（ＣＴＡＢ）络合等进行分离纯化，得一糖胺聚糖级分。经醋酸纤维素薄膜电泳显示为单一区带。化学组成分析表明：该级分氨基已糖含量较高（７１．３％），其中以氨基半乳糖为（５９％），含量少量的乙糖醛酸，含硫酸基、半乳糖、岩藻糖。元素分析表明其碳、氢、氮、硫的含量分别为３７．７％、５．８％、３．０％。对级分的残余氨基酸分析表明，８４．２％氨基酸已     

Family by environment interactions in shell size of 43-day old silver-lip pearl oyster (Pinctada maxima), five families reared under different nursery conditions

To understand the influence the environment and associated genotype by environment interactions will exert on future silver-lip pearl oyster (Pinctada maxima) selective breeding programs, this study assessed the relative performance in four shell growth traits of spat from five full-sib families, when spat were communally reared at different salinities (29, 34 and 40 ppt), food availability (high, medium and low), food quality (high, medium and low), and in a hatchery vs. ocean environment for 43 days.Rearing environment was found to influence growth expression, with significant differences evident when oysters were grown at different salinities in the ocean instead of hatchery, or when fed algae of differing nutritional quality. As indicated by MANOVA, family comparative growth performances were also altered when the environment changed, with significant environment by family interactions apparent in the food quality, food availability and hatchery vs. ocean rearing treatments. Changes in salinity, however, did not affect relevant family performances.These results indicate that growth and relative family performance in P. maxima may change dependent on local environmental conditions and that genotype by environment effects may need to be considered in breeding programs for this species.     

Evaluation of three phytoplankton species as food for the pearl oyster <Emphasis Type="Italic">Pinctada fucata</Emphasis>

In the pearl cultivation farms of the Ehime Prefecture, Japan, mass mortalities of the pearl oyster Pinctada fucata have occurred since 1994. The occurrences of mass mortality roughly coincided with a shift of the dominant phytoplankton from Skeletonema and Chaetoceros to Chaetoceros and Nitzschia all of which belong to Bacillariophyceae. Hence, we evaluated Nitzschia, together with Chaetoceros and Isocrysis, as food for the oyster. Wet weights, lengths, widths, glycogen contents, and growth rates in terms of wet weight of the oysters in all the feeding treatments were significantly higher than those in the non-feeding treatment. The highest glycogen content (2.34%) and growth rate (2.21 g month⁻¹) were found in the Chaetoceros treatment. Growth rate in the Isocrysis treatment (1.63 g month⁻¹) was also high, although glycogen content in this treatment (0.41%) was low. In the Nitzschia treatment, growth rate of the oyster (0.94 g month⁻¹) was the lowest and glycogen content (0.83%) was also low relative to that in the Chaetoceros treatment. Chlorophyll a concentration in fecal pellets was lowest in the Nitzschia treatment (<2.7 μg mg⁻¹), suggesting more complete digestion of Nitzschia by the oyster. Thus, Nitzschia was edible and digestible but not assimilated by P. fucata. We propose the following scenario for the relationship between Nitzschia dominance and mass mortality. When Nitzschia dominates in a culture area, the physiological condition of P. fucata deteriorates due to low assimilation of Nitzschia by the oyster, followed by susceptibility of the oyster to infection by agents lethal to the oyster.     

马氏珠母贝蛋白的分离及分子量分布研究

试验结果表明,马氏珠母贝全脏器各分离蛋白组分占总蛋白含量分别为:非蛋白氮1.48%,肌浆蛋白33.20%,肌原纤维蛋白13.14%,碱溶性蛋白21.54%,基质蛋白30.65%;贝肌肉各分离蛋白组分占总蛋白含量分别为:非蛋白氮0.83%,肌浆蛋白26.56%,肌原纤维蛋白18.48%,碱溶性蛋白30.34%,基质蛋白23.79%;马氏珠母贝蛋白氨基酸组成均衡,呈味氨基酸及支链氨基酸含量高,但在各蛋白组分中的含量存在一定差异性.利用聚丙烯酰胺凝胶电泳(SDS-PAGE)测定的分子量分布结果显示,2种原料蛋白的肌浆蛋白分子量分布范围较宽,集中在200～19 kDa,肌原纤维蛋白分子量分布集中在200～45 kDa,碱溶性蛋白集中分布在41～3 kDa.     

马氏珠母贝大亚湾和三亚野生种群内自繁及种群间杂交一代的RAPD分析

运用RAPD技术分析了广东大亚湾野生种群内繁殖一代DDl群体和海南三亚野生种群内繁殖一代SSl、两野生种群间杂交一代DS1群体各18个个体的遗传多样性。筛选的28个含10碱基的随机引物中，其中11个随机引物可产生稳定和可重复的多态扩增结果，共检测出86个位点，其中DDl群体有74个基因位点，其中56个表现多态，多态比例为75．68％；SSl群体79个基因位点，其中57个表现多态，多态比例是72．15％；DSl群体有72个基因位点，其中64个表现多态，多态比例为88．89％。用修正的Shannon表型多态性指数量化3个群体的遗传多态性，DDl、SSl和DS13个群体的遗传多态性分别为0．2280，0．2ll5和0．2456。不同地理种群间杂交能够增加子代的遗传多态性。     

企鹅珍珠贝和马氏珠母贝软体部脂肪酸组成

对企鹅珍珠贝和马氏珠母贝软体部脂肪进行了提取和测定。结果表明,企鹅珍珠贝和马氏珠母贝软体部脂肪含量分别为8.3%和9.6%。企鹅珍珠贝脂肪酸中DHA EPA的总含量为39.71%,比马氏珠母贝脂肪酸中DHA EPA的总含量(30.86%)高。2种珍珠贝软体部脂肪酸均具有重要的开发利用价值。     

马氏珠母贝不同地理种群内自繁和种群间杂交子一代主要性状的比较

为了培育马氏珠母贝新品种，开展了不同地理种群内自繁和种群间杂交的工作，获得了3个自繁群体和3个杂交群体，BB1、DD1和SS1分别来自北海野生种群(BW)、大亚湾野生种群(DW)和三亚野生种群(SW)自繁一代；BDl、BS1和DSl分别来自BW与DW、BW与SW以及DW与SW杂交一代。运用方差分析对6个子一代群体的5个主要性状(壳长、壳宽、壳厚、总体重和壳重)进行了比较，3个杂交群体未表现出杂种优势。但获得的6个群体将成为进一步选育的基本群体。子一代的变异性增加为进一步选育奠定了基础。