Cytogenetic mechanism for the aneuploidy and mosaicism found in tetraploid Pacific oyster Crassostrea gigas (Thunberg)     

ZHANG Zhengrui  WANG Xinglian  ZHANG Quanqi  and Standish Allen Jr. 《中国海洋大学学报(英文版)》2014,13(1):125-131

Chromosome constitution was investigated in adult tetraploid Pacific oyster produced by blocking the first polar body of triploid eggs which were fertilized with haploid sperms. A high incidence of aneuploid and heteroploid mosaics were found among the offspring. Of 20 individuals identified, only 9 (45%) were eutetraploid which contained 40 chromosomes; 2 (10%) were aneuploid (hypotetraploid), which contained 39 and 38 chromosomes, respectively; and 9 (45%) were heteroploid mosaics. One mosaic was consisted of cells containing 40 and 39 chromosomes, respectiovely (1:1 in cell number), while the other 8 were consisted of cells containing chromosomes varying between tetraploid and triploid. It was also interesting to note that 3 mosaics even contained some diploid cells with 20 chromosomes. A certain number of cells of 2 tetraploids and 8 mosaics spread with 32–37 well-scattered and some clumped chromosomes at metaphase. The percentage of aneuploid cells with chromosomes varying between triploid and tetraploid correlated significantly with that of heteroploid mosaics cells with clumping chromosomes (P<0.05). Our findings suggested that reversion existed in both tetraploid and triploid oyster and chromosome clumping may underline the chromosome elimination in tetraploid oyster. It seems that the reversing cells, at least some of them, continuously eliminate their chromosomes until the most stable diploid state is established.  相似文献   

Saldanha Bay,South Africa III: new production and carrying capacity for bivalve aquaculture     

TA Probyn  JF Atkins  GC Pitcher 《African Journal of Marine Science》2015,37(4):521-531

Measurements of NH₄, NO₃, urea and HCO₃ uptake using 15N and 13C stable isotope tracers were undertaken in Saldanha Bay, South Africa, between January 2012 and January 2013. These studies provide the first direct measurements of N utilisation by the plankton in the bay. Primary production in the bay is driven predominantly by the advection of nutrients from the neighbouring shelf environment during upwelling events, with terrestrial and other sources providing minor inputs. New production (NO₃-based) was calculated from the f-ratio and total primary production and was used to provide estimates of potential carrying capacity for bivalve culture. Despite the apparent light limitation of NO3 uptake in the winter, the availability of NO₃ appeared to exert the major influence on new production throughout the year. In addition, new production was modulated by NH₄ availability as shown by the suppression of NO₃ uptake by concentrations higher than 1?1.5?mmol m^?3. The estimated areal new production of 0.60?g C m^?2 d^?1 yielded a bay-wide annual estimate of 9 811 t C ha^?1 y^?1, slightly higher than previous calculations based on physical models. It is estimated that the total annual production of mussels and oysters, respectively, for a 1 000-ha cultivation area is approximately 40 000–53 000 t y^?1 (mainly Mytilus galloprovincialis) and 4 600–6 000 t y^?1 (Crassotrea gigas). The combined total production figures constitute only 24–31% of the surplus new production. A combined harvestable carrying capacity of 74 000–82 000 t y^?1 can be calculated from this surplus. However, from a management and ecological perspective, bivalve culture should be limited to well below this theoretical maximum. Even with this constraint, there appears to be considerable scope for expansion of bivalve farming over the modest, present levels with little jeopardy to ecological integrity.  相似文献   

长牡蛎(Crassostrea gigas)贝壳与外套膜中黑色素的提取和鉴定   总被引：1，自引：0，他引：1  

于文超  何成  武长路  王娇  李壮  郭婷  李永川  王晓通 《海洋与湖沼》2015,46(4):909-914

为了提取和鉴定长牡蛎(Crassostrea gigas)贝壳与外套膜中的黑色物质,选取贝壳与外套膜颜色均为黑色的长牡蛎,将贝壳及外套膜进行粉碎、盐酸水解、水浴加热、乙醚抽脂,从3份贝壳中提取出3份黑色固体物质,从3份外套膜中提取出3份黑色固体物质,将提取的黑色固体溶解于0.01m L/L氢氧化钠水溶液中,在150—500 nm的范围内测定紫外吸收光谱,发现其最大吸收峰在210 nm左右,随着波长增加,其吸光值迅速大幅度下降,与公认的黑色素紫外吸收光谱特征一致,从而首次确定长牡蛎贝壳与外套膜中的黑色物质为黑色素。  相似文献   

太平洋牡蛎中Cg-IL-17和Cg-TGF-β的表达及其免疫作用的研究     

董洪亮  刘乃国  倪娜  李彩玉  郑静  苗双 《海洋学报》2015,37(2):104-110

目的:探讨Cg-IL-17和Cg-TGF-β在太平洋牡蛎中表达的组织定位、免疫作用及其可能的机制。方法:采用Real-time PCR、原位杂交和图像分析的方法进行研究。结果:实时定量PCR研究表明,Cg-IL-17和Cg-TGF-β在弧菌感染后的太平洋牡蛎的鳃、外套膜、心包液、唇须、消化道和闭壳肌中表达明显增强。原位杂交实验结果表明,Cg-IL-17和Cg-TGF-β在未染菌组牡蛎的消化道、消化腺、鳃、唇须、外套膜中都有表达;染菌组以上各组织中的Cg-IL-17和Cg-TGF-β表达量均有显著增高,而消化道、消化腺中的表达量明显高于其他组织,闭壳肌中也均有微弱表达;感染弧菌前后两种基因在性腺中均未见表达。相关性分析发现这两种基因表达量在唇须和外套膜中具有明显的相关性。结论:Cg-IL-17和Cg-TGF-β具有多种生物学效应,且都参与了太平洋牡蛎的固有免疫反应;消化道可能是牡蛎主要的免疫反应器官之一;Cg-IL-17和Cg-TGF-β在唇须和外套膜中可能存在调控关系或协同作用。  相似文献   

The incentives of a resource owner: Evidence from a private oyster fishery     

《Marine Policy》2015

European flat oyster Ostrea edulis fisheries were once abundant around the UK coastline. The sole remaining productive O. edulis fishery in Scotland is in Loch Ryan. This fishery has been privately owned and managed by a single family since 1701. Economic theory predicts that ownership, whether public or private, is a necessary condition for rational fishery management. In this paper, a series of four leases and a licence are examined, covering an 85-year period over the 20th and 21st century, to examine whether the management of the Loch Ryan fishery conforms to the expected norms of rational management. The leases show that, over this period, the owners appear more willing to expend resources on regulating tenant behaviour, supporting the conclusion that successive generations of owners developed an evolving sense of what “rational management” might require. The results of this study could inform the management of other fisheries – both public and private – by emphasising the importance of learning from experience.  相似文献   

不同盐度和温度对熊本牡蛎(Crassostrea sikamea)稚贝生长与存活的影响   总被引：1，自引：0，他引：1  

王涛  李琪 《海洋与湖沼》2017,48(2):297-302

熊本牡蛎(Crassostrea sikamea)自然分布于中国长江以南沿海、日本有明海以及韩国沿海地区,具壳质坚硬、肉味清甜等特点,是巨蛎属牡蛎中重要经济种之一。为阐明熊本牡蛎稚贝生长发育的适宜盐度和温度范围,本研究分析了6个不同盐度(15、20、25、30、35和40)和5个不同温度(16、20、24、28和32°C)对熊本牡蛎稚贝生长与存活的影响。盐度实验结果显示,盐度15、20和25组中熊本牡蛎稚贝壳高和壳长显著高于盐度35和40组(P0.05),且随盐度增加,稚贝壳高、壳长表现为先升高后降低的趋势;盐度20组存活率最高,与盐度30和40组差异显著(P0.05);熊本牡蛎稚贝的适宜生长盐度为20—25,适宜存活盐度为15—25。温度实验结果显示,稚贝壳高和壳长在温度28°C组最大,随温度的降低,壳高、壳长也逐渐减小;温度20、24和28°C组存活率显著高于温度16和32°C组(P0.05);熊本牡蛎稚贝的适宜生长温度为24—28°C,适宜存活温度为20—28°C。熊本牡蛎稚贝对低盐高温有较强的适应能力。  相似文献   

Evidence of Ostrea lurida Carpenter, 1864, population structure in Puget Sound,WA, USA          下载免费PDF全文

Jake E. Heare  Brady Blake  Jonathan P. Davis  Brent Vadopalas  Steven B. Roberts 《Marine Ecology》2017,38(5)

Species traits that carry adaptive advantages such as reproductive timing and stress resilience may differ among populations. Knowledge and consideration of these traits should, therefore, be integrated into conservation efforts that include long‐term persistence of species. To test for adaptive differences between Olympia oyster, Ostrea lurida, populations a reciprocal transplant experiment was carried out monitoring survival, growth and reproduction using three established populations of O. lurida within Puget Sound, WA, USA. Performance differed for each population. Ostrea lurida from Dabob Bay had the highest survival at all sites but the lowest reproductive activity and growth. Oysters from Oyster Bay demonstrated the greatest proportion of brooding females at a majority of sites with moderate growth and survival. Together these data suggest the existence of O. lurida population structure within Puget Sound and provide information on how broodstock should be selected for restoration purposes.  相似文献   

海水主要离子在合浦珠母贝精子激活中的作用   总被引：1，自引：0，他引：1  

喻达辉  江世贵  苏天凤  陈竞春 《海洋学报》1999,21(6):134-137

合浦珠母贝(Pinctada fucata)是我国海产珍珠重要母贝,其大批量种苗的人工繁殖于70年代获得成功合浦珠母贝的繁殖生物学有其特殊的地方,即人工解剖获得的精子在自然海水中不运动,没有受精能力,需用一定的化学物质激活才能受精[1-3]。  相似文献   

珠江口沿岸牡蛎养殖场沉积物及牡蛎体内重金属含量与评价   总被引：10，自引：0，他引：10  

王艳  高芸  方展强 《热带海洋学报》2005,24(6):61-66

应用原子吸收分光光度计对珠江口9个牡蛎养殖场沉积物及近江牡蛎Crassostrea rivularis样品中的Cd、Cu、Zn、Pb、Cr和Ni的含量进行测定。结果显示,沉积物中的Cd、Cu、Zn、Pb、Cr和Ni的平均含量分别为0.35—3.8、32.4—108.0、58—395、13.2—96.1、14.7—39.9和9.35—40.15μg.g-1干重;牡蛎体内Cd、Cu、Zn、Pb、Cr和Ni的平均含量分别为0.11—12.07、128.8—380.6、1 456.2—1 938.4、0.43—0.98、3.26—10.53和1.44—3.31μg.g-1干重。河口区沿岸养殖牡蛎与沉积物中的Cd、Cr含量具显著相关(p<0.01;p<0.05),可作为Cd和Cr污染的良好指示生物。所有采样点牡蛎体内Pb和Cr含量均低于我国颁布的无公害水产品质量安全标准,但6个采样点的Cd含量略超过安全标准(1.00μg.g-1湿重);4个采样点的Cu含量略超过安全标准(50.00μg.g-1湿重),应引起有关部门的重视。  相似文献   

渤海湾西北岸中全新世埋藏牡蛎礁的硅藻记录及古环境意义   总被引：1，自引：0，他引：1  

李冬玲  范昌福  黄玥  蒋辉  王宏  商志文 《海洋通报》2009,28(3)

通过对渤海湾西北岸大吴庄牡蛎礁壳体内部的泥质填充物中硅藻组合的研究,试图探讨该区沉积硅藻组合变化指示的礁体古气候环境变化.分析结果表明,在 7 200～5 600 cal. a BP 整个礁体建造期间,沿岸种 Cyclotella stylorum 是含量最丰富的硅藻种类,其与海水种 Thalassionema nitzschioides 的含量变化指示了礁体生长区河流径流与海水相互作用的强弱波动,主要包括三个阶段:7 200～6 500 cal. a BP,礁体建造初期,礁体受海水影响显著;6 500～5 720 cal. a BP,礁体建造中期,礁体生长区的盐度降低,海水作用减弱,淡水作用增强;5 720～5 600 cal.a BP,礁体建造结束期,礁体生长区的盐度显著降低,礁体受海水影响进一步减弱.  相似文献