去掉角质层边缘前后企鹅珍珠贝形态性状的相关性及通径分析

根据观察,企鹅珍珠贝的形态差异较大,而去掉黑色角质层边缘的贝壳部分变化可能较小。为了更好地研究企鹅珍珠贝的生长及珍珠质颜色的形成,实验随机选取企鹅珍珠贝300枚,测量其总重、壳高、足丝直径等9个数量性状。杀贝后取左壳,用工具削去角质层边缘后测量壳重、壳高等11个相关指标。除重量性状、足丝直径和壳宽外,其余形态性状通过拍照结合Photoshop软件建立坐标系和像素测距测得。所得数据用SPSS 19进行分析。结果表明:去掉黑色边缘的贝壳壳高、对角线与壳长之间的相关性优于完整贝壳,说明去掉角质层边缘的贝壳形态变化更规律,具有更好的研究意义和价值。除足丝直径外,绝大部分性状间呈显著相关性(p0.05)。依据逐步回归建立了线性回归方程:Y1=-88.969+2.629X_(18)+8.321X_1+15.3X_2。通径分析中右壳重对总重的影响最大,其次是壳高和壳宽。实验结果为企鹅珍珠贝的选择育种等方面的应用提供了重要参考依据。     

培养条件对三角帆蚌外套膜离体上皮组织珍珠质分泌能力的影响（简报）

珍珠是由珍珠贝外套膜的上皮细胞受到外源刺激物刺激形成珍珠囊（pearl—sac）,并由珍珠囊产生的钙质分泌物．其分泌物逐渐包围刺激原．使之体积急剧增长而形成的,珍珠质（nacre）是由大于95％的碳酸钙晶体与约5％的角壳蛋白组成的生物矿化产物。因此珍珠贝的外套膜在珍珠形成中起着重要的作用。珍珠贝外套膜的体外培养已开展了一些初步的研究工作。     

企鹅珍珠贝不同地理群体遗传多样性的fAFLP 分析

为阐明企鹅珍珠贝(Pteria penguin)不同地理种群的遗传多样性机制, 采用荧光标记扩增片段长度多态性(fAFLP)技术分析了企鹅珍珠贝广西涠洲岛、广东流沙湾和海南黎安3 个不同地理群体的遗传多样性。选取7 对引物组合对90 个个体(每个群体30 个)进行fAFLP 扩增, 结果发现每个个体均能扩增出清晰的、可重复的扩增条带, 每对引物的扩增位点数在100—163 之间, 共得到895 个扩增位点, 多态位点数为865 个; 涠洲岛、流沙湾和黎安群体的多态位点比例分别为70.73%、63.13%、66.82%。Nei 遗传多样性指数为0.1634、0.1558、0.1783, Shannon 遗传多样性指数为0.2635、0.2474、0.2932。3 个群体间遗传相似度在0.9722—0.9824之间, 遗传距离在0.0177—0.0282 之间。根据遗传距离绘制UPGMA 聚类图, 但Mantel 检验结果显示企鹅珍珠贝三群体间的遗传距离与地理距离之间无显著相关。Shannon 遗传多样性指数和AMOVA 分析, 结果均显示企鹅珍珠贝的遗传变异主要来源于群体内个体间, 7.91%的遗传变异来自群体间, 92.09%的遗传变异来自群体内。分析群体的显性基因型频率分布和基因流Nm 发现3 个群体有基本相同的遗传结构, 有明显的基因交流。研究结果表明北海涠洲岛群体、湛江流沙湾群体和海南黎安群体的企鹅珍珠贝种质有较高的多态位点比例, 但未发生显著地理分化。这一结果为我国企鹅珍珠贝的良种选育以及种质资源保护措施的制定提供了参考依据。       

企鹅珍珠贝微卫星标记与生长性状的相关性研究

研究利用5个高度多态性的微卫星标记,对500个企鹅珍珠贝(Pteria penguin)的4个生长性状进行了关联分析。结果显示, QEB-D15和CL-232两个微卫星标记与企鹅珍珠贝的壳宽呈极显著相关(P<0.01);位点QEBD15基因型是239/263的个体壳宽为最大值,基因型是239/273的个体壳宽为最小值,推测263 bp等位基因与壳宽之间存在正相关关系,而273 bp等位基因与壳宽之间存在负相关关系;位点CL-232基因型为157/174的个体壳长、壳宽、总重的均值较同一位点的其他基因型均为最大值,该基因型推测为优势基因型;而基因型为177/192的个体壳长、壳宽、壳高和总重的均值较同一位点的其他基因型均为最小值,推测该基因型为劣势基因型,上述结果可为企鹅珍珠贝分子标记辅助选择育种提供理论依据和参考。     

企鹅珍珠贝彩虹珠的研究初报

利用企鹅珍珠贝培育出了不同颜色的天然彩色珍珠,俗称“彩虹珠”,并对其形状及颜色进行了描述。“彩虹珠”颜色的形成与企鹅珍珠贝贝壳珍珠层的本身色泽及插核小片的位置有关,其珍珠质的分泌速度也较快,经3个月育珠,珠层厚度可达300μm以上,经9个月育珠可达890μm。但由于插核部位狭小,现有的技术水平还不能生产大型珍珠。     

5种常见珍珠贝的系统发育和遗传多样性分析

利用RAPD标记分析了珠母贝属常见的马氏珠母贝、大珠母贝、珠母贝、解氏珠母贝以及珍珠贝属常见企鹅珍珠贝的系统发育,同时分析了马氏珠母贝和大珠母贝不同地理种群的遗传多样性,并以邻接法(neighbor-joining,NJ)构建了种间及种群间的系统分支图.结果表明:(1)在珍珠贝5种9个种群中,大珠母贝的4个种群最早聚在一起分别成为2个姊妹群,这2个姊妹群聚合为1个单元群后,又与珠母贝聚在一起,然后才与马氏珠母贝姊妹群聚合成的单元群聚合,再与解氏珠母贝聚合,最后才与企鹅珍珠贝聚合;(2)珠母贝属4种珍珠贝进化程度由低到高的等级顺序为解氏珠母贝-马氏珠母贝-珠母贝-大珠母贝;解氏珠母贝是最晚形成的种类;(3)比较5种珍珠贝野生种群的Nei's多样性和Shannon多样性值为:马氏珠母贝(0.411 1和0.593 3)>珠母贝(0.397 1和0.578 4)>企鹅珠母贝(0.383 1和0.549 3)>大珠母贝(0.338 8和0.499 9)>解氏珠母贝(0.301 6和0.445 2);(4)无论是马氏珠母贝,还是大珠母贝,野生种群的遗传多样性值均大于养殖种群.     

熊果苷和丙戊酸影响企鹅珍珠贝(Pteria penguin)贝壳色泽

企鹅珍珠贝(Pteria penguin)是我国最具潜力培育大型海水珍珠的优质母贝,其贝壳色泽及珍珠层颜色与黑色素(melanin)的合成水平有关。为了筛选安全有效的企鹅珍珠贝黑色素抑制剂和增强剂,探讨其有效使用浓度和作用时间,分析其毒副作用,实验分别采用不同浓度的熊果苷(arbutin)和丙戊酸(valproic acid)浸泡1月龄稚贝不同时间,观察3月龄,5月龄和7月龄幼贝壳色,并统计熊果苷和丙戊酸的使用对幼贝变色率、存活率、壳长、壳高、壳宽的影响。结果显示,2 mmol/L熊果苷处理稚贝1h或5 mmol/L丙戊酸处理1h即可显著提高壳色变异的比率(p0.05),且幼贝变色率随熊果苷和丙戊酸的浓度和作用时间的增加而增加。对熊果苷和丙戊酸的毒性检测发现,熊果苷达到10 mmol/L处理8h时,仍不会影响幼贝的存活率、壳长、壳高、壳宽(p0.05);但丙戊酸在浓度为5 mmol/L处理4h时,幼贝的存活率即显著下降,壳长、壳高和壳宽亦显著低于对照(p0.05)。研究表明,熊果苷和丙戊酸对企鹅珍珠贝幼贝而言分别是有效的黑色素抑制剂和增强剂,熊果苷在10 mmol/L处理8h以下都未检测到毒副作用,丙戊酸在5 mmol/L处理4h时即存在一定毒性。     

腹腔镜手术治疗粘连性肠梗阻的疗效及安全性研究

目的：探讨腹腔镜粘连松解术治疗粘连性肠梗阻（AIO）的疗效，减少再梗阻率。方法：将120 例AIO 患者随机分为两组，每 组60 例，开腹组实施开腹手术，腹腔镜组实施腹腔镜粘连松解术，观察两组术后恢复及并发症发生情况，对再梗阻危险因素进行 Logistic 回归分析。结果：腹腔镜组术中失血量（73.48± 9.32）mL，少于开腹组的（207.45± 33.21）mL（P<0.05）；腹腔镜组手术、术后 镇痛、下床活动、肠恢复蠕动、肛门恢复排气、拔除尿管及住院时间分别为（69.15± 10.13）min、（14.67± 7.23）h、（27.14± 7.04）h、 （3.11± 0.96）d、（3.24± 1.02）d、（3.37± 1.23）d、（7.95± 3.05）d，均短于开腹组的（83.84± 9.24）min、（27.38± 8.02）h、（36.23± 5.87） h、（4.05± 1.35）d、（4.35± 1.74）d、（5.02± 2.13）d、（10.35± 3.71）d（P<0.05)；腹腔镜组并发症发生率、再梗阻率分别为10.00%、 10.00%，均低于开腹组的33.33%、40.00%（P<0.05)；多因素Logistic 回归分析显示开腹手术、手术时间≥ 60 min 是再梗阻发生的独 立危险因素。结论：腹腔镜手术治疗AIO 疗效优于开腹手术，而且并发症与再梗阻率低。     

秋茄幼苗对盐度、淹水环境的生长适应

室内模拟12个盐度+淹水处理组合对红树植物秋茄幼苗生长的影响,测定不同组合下秋茄幼苗的株高、茎高、基径、节数、叶数、根生物量、茎生物量、叶生物量及总生物量等9项指标.结果表明:盐度-淹水交互处理及盐度处理对秋茄各项生长指标影响显著,淹水处理对株高、茎高、基径、节数及叶数影响不显著,对根生物量、茎生物量、叶生物量及总生物量影响显著;秋茄幼苗生长量及生物量积累随盐度升高而降低,随淹水时间增加而下降;结合主成分分析得出,盐度7‰+淹水2 h下秋茄幼苗生长最好,临界胁迫组合为盐度21‰+淹水8 h处理组.     

Secretion of byssal threads in Mytilus galloprovincialis: quantitative and qualitative values after spawning stress

The effect of spawning events of the mussel Mytilus galloprovincialis on both quantitative and qualitative values of byssus secretion and its associated attachment force was investigated. Byssogenesis rates and absorption efficiency values were significantly reduced after spawning of individuals. However, the maintenance of individuals under sub-optimal conditions (lack of microalgae in the diet) for a week caused no effect on thread’s number. Surprisingly, the attachment force varied within a narrow range of values (1.7–1.9 N) with the exception of a significant drop in the experimental group spawned and kept unfed (1.0 N; P < 0.001), most likely due to a similar pattern of the thread’s thickness variability. Qualitative analysis concerned to the amino acid composition of the byssus highlighted a higher presence of the basic residues histidine and lysine in threads secreted by spawned individuals. The presence of both histidine and lysine residues in the byssal collagen is associated to the formation of cross-links and specifically histidine has a functionality with a pronounced effect on metal chelation to stabilise the integrity of the byssus. Results reported here evidence the necessity to integrate all components that eventually determines the attachment strength of the mussels to get more insight to the plasticity of such secretion. Morphology of the byssus (thickness) secreted under different endogenous conditions of mussels was the major parameter to explain variability in the attachment force. Moreover, aminoacidic composition as quality term of the byssus secreted may also contribute to understand the plasticity of this secretion and needs to be extended in further surveys.     

Effects of temperature,salinity and agitation on byssus thread formation of zebra musselDreissena polymorpha

Byssus thread production ofD. polymorpha under different conditions of temperature, salinity and agitation were studied in the laboratory. The acclimation to salinity and temperature greatly affects the byssus production ofD. polymorpha. Byssus production of mussels was significantly reduced when temperature increased beyond 20°C and decreased below 10°C. Mussels with cut threads (for counting), produced a substantially increased number of threads. However, mussels with uncut byssus threads were comparatively more mobile. Byssus production of mussels did not vary significantly at salinities up to 3. Beyond this salinity byssus production was reduced significantly. Mussels increased their byssus production with increasing frequency of agitation.     

The effect of spawning salinity on eggs of spotted seatrout (Cynoscion nebulosus, Cuvier) from two bays with historically different salinity regimes

Spotted seatrout are capable of spawning in a wide range of salinities. Along the Texas Gulf Coast, bay salinities increase from an average of 14 ppt in Galveston Bay to an average of 40 ppt in Lower Laguna Madre due to the negative gradient of freshwater inflow from north to south. Tagging studies have shown that the majority of spotted seatrout do not migrate between adjacent bay systems. Spawning salinity has been shown to affect many properties of eggs including the diameter and salinity of neutral buoyancy. Spotted seatrout from two historically different salinity regimes (Matagorda Bay (MB) and Upper Laguna Madre (ULM)) were kept in the laboratory and induced to spawn in three salinities: 20, 30, and 40 ppt. The purpose of this study was to evaluate eggs at each of the three salinities and between the two bay systems. Two-way ANOVA showed a significant effect on the egg diameter of bay and spawning salinity, and a significant interaction between bays and spawning salinity. No significant difference in size at hatch was found between spawning salinities or between bays. Hatch rates in spawning salinity were >90% in all cases. Regression of wet weight on spawning salinity was highly significant for both bays. Eggs spawned in 20 ppt have the largest wet weight and eggs spawned in 40 ppt have the smallest wet weight, irrespective of parental bay origin. Percentage of water varied between 92% for 20 ppt spawned eggs and 86% in 40 ppt spawned eggs. Neutral Buoyancy Salinity (NBS) of eggs increased with increasing spawning salinity. Eggs spawned by the Upper Laguna Madre fish held at 20 ppt were not positively buoyant at 20 ppt. The results of this study suggest that spotted seatrout are locally adapted to the prevailing salinity regime within an estuary.     

盐度对黄鳝摄食节律和排粪时间的影响

室内研究了不同盐度(0、2、4、6、8、10和12 g·L^-1)对经过摄食驯化的黄鳝摄食节律和排粪时间的影响.结果表明：盐度对黄鳝的摄食节律没有显著影响（P>0.05）,但不同时段的摄食比例存在极显著差异(P<0.01),每昼夜只有1个摄食高峰期.黄鳝排粪分批次完成,不同盐度下其批次不同.在盐度为0（对照）、2、8、10和12 g·L^-1条件下黄鳝均为3批排粪,在盐度4和6 g·L^-1下排粪批次分别为4批和5批.不同盐度下黄鳝的同批排粪时间均存在极显著差异(P<0.01),对照组的前3批排粪时间极显著高于其它组(P<0.01),即对照组前3批排粪相对推迟4～25 h.研究结果将为盐碱、滩涂水域人工养殖黄鳝的摄食管理和水质调控提供理论依据.     

水体盐度对中华绒螯蟹成体雄蟹渗透压调节和生理代谢的影响

为研究长期不同水体盐度对中华绒螯蟹(Eriocheir sinensis以下简称河蟹)成体雄蟹渗透压调节和生理代谢的影响, 在不同水体盐度条件下(0、6、12和18)对河蟹雄体进行为期60d的养殖实验, 并分别检测其渗透调节及生理代谢相关指标。结果显示: (1)血清渗透压、Na+、Mg2+和Cl-含量随水体盐度上升而显著上升(P0.05), K+和Ca2+含量有上升趋势, 但各盐度组差异不显著(P0.05); 无论何组雄蟹, 其血清渗透压均显著高于对应的水体渗透压; (2)0组雄蟹后鳃Na+/K+-ATP酶活性显著高于其他组(P0.05), 其他各组间差异不显著(P0.05); (3)就血清生理代谢指标而言, 12组雄蟹血清中甘油三酯(TG)含量显著高于其他组(P0.05), 而尿酸(UA)、葡萄糖(Glu)、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性相对较低; 所有组尿素(Urea)、碱性磷酸酶(ALP)含量差异不显著(P0.05); (4)就肝胰腺生理代谢指标而言, 6组肝胰腺MDA含量和-谷氨酰转肽酶(-GT)活力最低, 12组酸性磷酸酶(ACP)和-GT活性显著高于其他盐度组(P0.05)。因此, 适当提高水体盐度可提高河蟹成体雄蟹的血清渗透压及其主要离子含量, 同时降低其后鳃中Na+/K+-ATP酶活性。肝胰腺和血清代谢指标暗示12盐度组雄体的代谢水平相对较低, 具有较强的免疫性能和抗氧化能力。     

Green mussel Perna viridis L.: attachment behaviour and preparation of antifouling surfaces

The green mussel Perna viridis LINNE can be kept in simulated seawater for more than 6 months in good condition. The mussel forms many threads by secreting an adhesive protein from the foot, and attaches with more than 50 byssal threads, which makes most mussels clump together. In order to investigate the preparation of the antifouling surfaces toward green mussels, the attachment of mussels was tested using glass surfaces modified with silane coupling agents, together with non-treated material surfaces such as glass and silicone. The correlation between the attachment percentage and the mean number of the secreted byssus was highly significant, indicating that the mussel selects a favorable surface prior to the secretion of byssus. The relationships between the mussel attachment and the surface chemical parameters (surface free energy (sfe) and its dispersion and polar components) were examined based on a working hypothesis, which we have previously reported. The result of statistical regression test indicated that a certain correlation was found between the dispersion component and the mussel attachment, while the polar component did not correlate to the mussel attachment. The present surface chemical approach provided an additional clue for the preparation of ecologically clean antifouling materials that takes into account the combination of the wettability of both the marine adhesive proteins (MAP) and the modified surfaces.     

盐度对大麻哈鱼幼鱼血液生化指标及肝组织的影响

模拟大麻哈鱼幼鱼降海洄游水域环境盐度,设0（淡水对照）、5、10、15、20共5个盐度组,以体质量（26.57±6.32）g、全长（14.44±1.05）cm幼鱼分别进行130 d饲养试验,通过血液生化指标分析及肝组织观察,研究了大麻哈鱼降海期对不同盐度适应过程的生理变化.结果表明: 血清渗透压和血清Na⁺、Cl^-变化趋势与水体盐度变化基本一致.高盐度(15、20)组血清Na⁺、Cl^-、Mg²⁺含量与低盐度(5)组和淡水组差异显著;各盐度处理组血清K⁺含量均显著低于淡水组.盐度10组的血糖浓度显著高于盐度5和20组;各盐度处理组总胆汁酸与淡水组差异显著;幼鱼血清总蛋白(TP)、白蛋白(ALB)、球蛋白(GLB)含量随盐度的升高总体呈下降趋势,其中淡水组TP和GLB含量显著高于盐度15和20组.淡水组血清谷丙转氨酶（ALT）、谷草转氨酶(AST)与高盐度组差异显著.低盐度(盐度0、5)下试验幼鱼肝细胞有部分破裂现象,肝组织空泡化严重.各组试验鱼生长和成活率无明显差异,生理生化指标显示大麻哈鱼幼鱼降海期适应盐度以10～20为宜.     

Effect of temperature, salinity and delayed attachment on development of the solitary ascidian Styela plicata (Lesueur)

The solitary ascidian Styela plicata (Lesueur) is a common member of epibenthic marine communities in Hong Kong, where seawater experiences extensive seasonal changes in temperature (18-30 °C) and salinity (22-34‰). In this investigation, the relative sensitivity of different developmental stages (i.e., duration of embryonic development, larval metamorphosis and post-larval growth) to various temperature (18, 22, 26 and 30 °C) and salinity (22‰, 26‰, 30‰ and 34‰) combinations is reported. Fertilized eggs did not develop at lower salinities (22‰ and 26‰). At higher salinities (30‰ and 34‰), the duration of embryonic development increased with decreasing temperature (18 °C: 11.5±0.3 h; 30 °C: 8.5±0.3 h). More than 50% of larvae spontaneously attached and metamorphosed at all the levels of temperature and salinity tested. At higher temperatures (22, 26 and 30 °C) and salinities (30‰ and 34‰), functional siphon developed in about 72 h after hatching, whereas at low temperature (18 °C), siphon developed only in <30% of individuals in about 90 h. However, none of the metamorphosed larvae developed subsequently at low salinity (22‰). When forced to swim (or delayed attachment), larvae lost about 0.27 mJ after 48 h (about 22% of the stored energy). Such a drop in energy reserves, however, was not strong enough to cause a significant impact on post-larval growth. This study suggests that temperature and salinity reductions due to seasonal monsoon may have significant effect on the embryo and post-larval growth of S. plicata in Hong Kong.     

Effects of low salinity on metamorphosis in estuarine colonial ascidians

Abstract. We studied the effects of brackish water on larval attachment, events of metamorphosis, and juvenile mortality in three colonial ascidian species that live in a Florida coastal lagoon. Eudistoma olivaceum and Eudistoma hepaticum are restricted in their adult distribution to areas of relatively high and constant salinity near inlets, whereas Ecteinascidia turbinata extends more than 20 km into the Indian River, where salinity can be much more variable. In all three species, metamorphosis proceeded more quickly at 33 ppt than at lower salinities. The thresholds for successful metamorphosis differed among species in a manner that corresponded to the adult distributions, with E. turbinata being capable of completing metamorphosis at salinities as low as 22 ppt, E. hepaticum as low as 24 ppt, and E. olivaceum as low as 26 ppt. Larvae of both Eudistoma species delayed settlement in very low salinity water, whereas those of E. turbinata settled very quickly, then failed to complete metamorphosis. Juvenile mortality at salinities lower than 22 ppt was 100% for all three species. Survival in salinities higher than 22 ppt was strongly correlated with salinity in E. olivaceum and E. hepaticum , but not E. turbinata.