盐度对近江牡蛎耗氧率、排氨率、O:N 和吸收率的影响

以半现场流水槽法研究了不同盐度(5、10、15、20、25、30、35)对近江牡蛎(Crassostrea hongkongensis)耗氧率、排氨率、O:N、吸收率的影响,并测定了盐度为20条件下牡蛎耗氧率和排氨率的周日变化.结果表明,近江牡蛎耗氧率、排氨率、O:N先随着盐度的升高而下降,在20左右降到最低,随着盐度继续上升,又升高;而近江牡蛎的吸收率先随着盐度的升高而升高,在20左右达到最高,然后随盐度升高而下降.根据数据得出耗氧率与盐度的拟合方程: y=0.0033x2-0.1161x+1.5523, R2=0.9018;排氨率与盐度:y=0.0001x2-0.0041x+0.0871, R2=0.9889;O:N与盐度:y=0.0016x3-0.0782x2+0.9051x+10.818, R2=0.955;吸收率与盐度: y=-0.0011x2+0.0399x+0.4393.R2=0.9453.一日内,8时、14时、19时、22时4个时间点,近江牡蛎耗氧率和排氨率变化较大,在14时最大,表明该时点其代谢活动最强.     

Effects of salinity on embryonic development,survival, and growth of Crassostrea hongkongensis

This study examined the effects of salinity on embryonic development, survival, and growth of the Hong Kong oyster Crassostrea hongkongensis. The embryos, larvae, and juveniles of C. hongkongensis were held in artificial seawater at three different salinities (low, 15; medium, 23; and high, 30) to determine the optimum hatchery and nursery conditions for mass production of the seeds. Results showed that the percentage production of straight-hinged larvae from fertilized eggs was significantly lower at the high salinity than at the low- and medium-salinities (P < 0.05). The survival rates of larvae and juveniles differed significantly among the three salinity trials, with the highest survival rate observed at the low salinity (P < 0.05). The shell height of larvae was significantly larger at the low salinity than at the high and medium salinities from days 9 to 15 (P < 0.05), whereas that of juveniles was significantly larger at the low salinity than at the high and medium salinities on day 70 (P < 0.05). These results indicate that the larvae and juveniles of C. hongkongensis are tolerant to a wide range of salinities (15 to 30), but show better growth and survival at relatively low salinities. Thus, it is recommended to use relatively low salinities in hatchery and nursery systems for improved yields of C. hongkongensis.     

长牡蛎F3 代快速生长选育群体生长特性的研究

采用模型拟合方法研究了长牡蛎(Crassostrea gigas)F3代快速生长选育群体不同时期各生长性状的发育规律。结果表明,长牡蛎幼虫期壳高(SH)、壳长(SL)对日龄(t)的回归遵循Logistic模型,生长方程分别为SH=455.612/(1+9.500e-0.142t),R2=0.999;SL=462.476/(1+8.026e-0.108t),R2=0.996。幼虫期壳高与壳长成直线相关,回归方程为SL=0.76SH+18.82,R2=0.994。长牡蛎养成期各生长性状呈现明显的季节变化,壳高(SH)、壳长(SL)、壳宽(SW)和总质量(TW)对月龄(X)的多项式回归方程分别为SH=-0.0297X4+1.0365X3-12.0220X2+57.6500X-68.9260,R2=0.985;SL=-0.0173X4+0.5893X3-6.5702X2+30.2420X-34.4150,R2=0.986;SW=-0.0068X4+0.2620X3-3.2806X2+16.9170X-22.1410,R2=0.956;TW=-0.0219X4+0.8234X3-10.1680X2+50.7040X-85.4110,R2=0.972。壳高、壳长、壳宽与总质量均呈幂函数相关,回归方程分别为SH=23.645TW0.3213,R2=0.998;SL=12.337TW0.3776,R2=0.995;SW=6.611TW0.3589,R2=0.981。     

Tetraploid induced by physical and chemical methods in Jinjiang oyster(Crassostrea rivularis)

ＴｅｔｒａｐｌｏｉｄｉｎｄｕｃｅｄｂｙｐｈｙｓｉｃａｌａｎｄｃｈｅｍｉｃａｌｍｅｔｈｏｄｓｉｎＪｉｎｊｉａｎｇｏｙｓｔｅｒ（Ｃｒａｓｓｏｓｔｒｅａｒｉｖｕｌａｒｉｓ）￥ＲｏｎｇＳｈｏｕｂａｉ，ＳｈｉＳｈｕｍｅｉ，ＭｃＱｉｒｏｎｇ，ＬｉｕＳｈａｅｑｉｏ...     

长牡蛎繁殖期糖原含量与类胰岛素基因表达的相关性分析

为探究长牡蛎在繁殖期间的糖原含量与类胰岛素基因(cgMIP123、cgMIP4、cgMILP7、cgILP)和相关转录调控因子(cgPdx)相对表达量的相关性,自2020年5月至2020年10月采集了山东胶南养殖海区的长牡蛎,测定了血糖含量、糖原含量、条件指数、类胰岛素基因相对表达量及环境因子(酸度、温度、盐度)等数据,采用多元统计方法对数据进行分析。logistic回归分析结果显示,长牡蛎配子排放前后血糖含量和内脏团糖原含量具有显著差异。构建的回归模型可以通过血糖含量和内脏团糖原含量准确判断配子是否已经排放,区分度C-index为0.903,Hosmer-Lemeshow拟合优度检验χ²值为9.06,P>0.05,验证结果显示该模型可靠。多元线性回归分析结果显示:条件指数与cgMIP123和cgMIP4基因的相对表达量具有相关性,R²为0.91,P值为0.0076,极显著相关;内脏团和唇瓣组织的糖原含量与ILPs和cgPdx相对表达量具有一定的相关性,其中cgMILP7的相对表达量与内脏团和唇瓣组织的糖原含量呈负相关,cgPdx相对表达量与唇瓣组织的糖原含量呈负相关,cgMIP4和cgILP的相对表达量与糖原含量呈正相关。     

利用不同盐度诱导长牡蛎三倍体的研究

采用低盐度(4、6、8、10、12、14、16)和高盐度(40、45、50、55、60、65、70)在40%~50%受精卵出现第一极体时处理10和15min,进行长牡蛎三倍体的诱导。在低盐度诱导三倍体实验中,随着盐度降低,D型幼虫孵化率逐渐降低,处理10和15min的卵裂率差异显著(P0.05),孵化率差异不显著(P0.05)。当盐度为8时,处理受精卵10与15min,三倍体诱导率最高分别可达84.4%和91.0%,两处理组三倍体诱导率差异显著(P0.05)。在高盐度诱导三倍体实验中,随着盐度升高,D型幼虫孵化率逐渐降低,处理10和15min的卵裂率和孵化率均差异显著(P0.05)。当盐度为55时,处理受精卵10min,三倍体诱导率最高为80.3%;当盐度为60时,处理受精卵15min,三倍体诱导率最高为97.1%,两处理组三倍体诱导率差异显著(P0.05)。研究发现,在盐度为8和60条件下,40%~50%的受精卵出现第一极体时,处理15min,长牡蛎三倍体诱导率最高。     

长牡蛎基因组微卫星引物的开发和特性描述

长牡蛎于20世纪80年代从日本引进中国.在我国,长牡蛎已经成为重要的贝类养殖产业之一.本实验从全基因组上筛查微卫星序列,在微卫星筛查的范围、数目和类型上是传统的富集文库法开发微卫星所无法比拟的.利用基因组微卫星序列总共设计了104对引物,54对引物能扩增出目的片段,其中有34对引物显示多态性扩增,占32.7％,20对引...     

雄性三倍体长牡蛎繁殖潜力的初步研究

国内外很多人做过三倍体长牡砺的诱导工作，但在三倍体性腺发育及配子活力方面的研究，目前仅见Ａｌｌｅｎ等１９８６年和１９９０年对三倍体的海螂和长蛎异常配子的发生报道。Ｃｏｘ１９９６年研究了悉尼岩牡蛎三倍体性腺发育情况，姜卫国等对三倍体合浦珠母贝的生殖腺进行了观察，李霞［１］对三倍体长牡蛎的性腺发育做了较系统的分析和总结。作者用流式细胞仪对长牡蛎Ｃｒａｓｓｏｓｔｒｅａ　ｇｉｇａｓ二、三倍体的性腺细胞进行了初步分析，回答了三倍体长牡蛎生殖潜力及性比方面的一些问题，为进一步研究三倍体长牡蛎的生长、繁殖、杂…     

The Ectoparasitic Gastropod Boonea (= Odostomia) impressa: Population Ecology and the Influence of Parasitism on Oyster Growth Rates

Abstract. Boonea (= Odostomia) impressa is a common ectoparasite of oysters. In the laboratory, small oysters (Crassostrea virginica) parasitized by natural densities of B. impressa produced 75 % less new shell than unparasitized oysters. Shell deposition rates of previously parasitized oysters increased significantly after all B. impressa were removed. Thus, the decrease in growth rate, although significant, apparently was not permanent. B. impressa preferentially parasitized small, living oysters (≤2.5cm) in the field, even though a higher percentage of large, living oysters (>2.5cm) was available. The snails maintained an aggregated distribution on the oyster reef. The number of B. impressa per oyster clump was positively correlated with the number of living oysters per clump, however some clumps with few or no living oysters had many B. impressa. Thus, food availability only partially explained the pattern of distribution. B. impressa was very mobile. About 50 % of the population moved in one week. Reproduction occurred throughout the year with a peak period in May. Recruitment was greatest in July, however new recruits were observed throughout the year. The reduction in growth rate of parasitized oysters, the snaiľs propensity towards parasitizing small oysters and the snail's tendency to be contagiously distributed suggests that B. impressa potentially exerts a significant influence on the population structure and health of oyster populations.