Cryopreservation of strip spawned sperm using non‐programmable freezing technique in the blue mussel Mytilus galloprovincialis

In this study, a non‐programmable freezing technique has been developed with the strip spawned blue mussel (Mytilus galloprovincialis) sperm. The key parameters optimized including (1) cryoprotectant agents (CPAs); (2) cooling temperature; (3) thawing temperature; (4) sugar and amino acid supplementation and (5) sperm to egg ratio. The fertilization rate and/or integrity of plasma membrane and acrosome were used as sperm quality assessment indicators. The highest post‐thaw sperm fertilization rate of 95% was achieved, when sperm were cryopreservated in 8% dimethyl sulfoxide at 7.8 cm above the liquid nitrogen surface and thawed in a 60°C seawater bath. The addition of glucose, sucrose or trehalose in dimethyl sulfoxide did not, whereas 0.8% glycine did significantly improve the post‐thaw sperm fertilization rates. The fluorescent evaluation has demonstrated that the addition of glycine significantly improved the post‐thaw sperm acrosome integrity, revealing a positive role of glycine in the improvement of post‐thaw sperm quality in blue mussels.     

Surface-exposed expression of Edwardsiella tarda EseB in live attenuated Vibrio anguillarum based on novel surface display systems

Live, attenuated Vibrio anguillarum strains can serve as vectors for the delivery of heterologous antigens for development of multivalent recombinant vaccines. Based on the outer membrane anchoring elements of V. anguillarum , we have previously constructed several efficient surface display systems Lpp-Omporf1, Lpp-OmpU, Lpp-Omp26La, Wza-Omporf1, Wza-OmpU and Wza-Omp26La. In this study, with these constructed surface display systems, a putative antigen protein EseB from pathogenic Edwardsiella tarda was successfully expressed on the surface of an attenuated V. anguillarum strain to get multivalent vaccine candidates. Further immune protection evaluation in zebra fish ( Danio rerio ) demonstrated that the V. anguillarum EseB-display strain AV/pW-26La-B could trigger full protection against V. anguillarum infection and early protection against E. tarda infection in the immunized fish. These results suggest that surface display of heterologous protective antigens in attenuated V. anguillarum could be used as a tool to develop potential V. anguillarum vector vaccine.     

日本对虾越冬亲虾性腺促熟及工厂化育苗技术研究

1997、1998年利用越冬亲虾进行性腺促熟,用镊烫法切除眼柄,促进亲虾发育。结果:两年共培育亲虾雌虾8204尾。雄虾5683尾,获交尾虾5360尾。交尾率为71.81％。每年两批育苗,共利用水体1720m~3,育出0.7～1.1cm的虾苗12450万尾,平均单位水体出苗量为7.24万尾/m~3,效益显著。     

Can fermented soybean meal and squid by‐product blend be used as fishmeal replacements for Japanese flounder (Paralichthys olivaceus)?

An experiment was carried out to evaluate fermented soybean meal and squid by‐product blend (1:1) (FP) as replacement of fishmeal (FM) for Japanese flounder, Paralichthys olivaceus. Five isocaloric (19 kJ g^?1) diets were prepared by replacing 0 (FP0), 12 (FP12), 24 (FP24), 36 (FP36) and 48% (FP48) FM protein with FP. Triplicate groups of juveniles (mean weight of 3.9 g) were delivered the test diets for 8 weeks in a flow‐through sea water system. The results showed that there were no significant differences (P > 0.05) among the growth rates of fish fed FP0, FP12, FP24 and FP36 diets. Growth and nutrient utilization parameters were significantly reduced in fish fed FP48 diet. Although, whole body proximate composition of fish were not significantly affected by the dietary treatments compared to the control; methionine and phenylalanine contents were significantly decreased in FP48 group. Protein retention was also significantly decreased in the similar group of fish. Dietary treatments did not alter most of the plasma metabolites, while some of the health parameters were improved in the replacement groups. Results suggested that FP is a potential candidate for alternative protein ingredient in aquafeed and can replace 36% FM protein in the diet of Japanese flounder.     

虹鳟鱼的养殖技术特点和前景展望

本文阐述了养鳟业的经济意义和价值,并从养鳟用水和生产方式、苗种生产、食用鱼养成、养鳟饲料、海水养鳟,疾病防治等方面总结了养鳟基本技术,同时对我国养鳟历史作了回顾,提出了我国养鳟业的发展前景。     

高寒鲤染色体核型分析

采用植物血球凝集素（ＰＨＡ）体内注射,肾组织细胞短期培养,常规空气干燥法制备了高寒鲤染色体,核型分析结果是：高寒鲤染色体的核型公式为２ｎ＝１００＝２８ｍ＋２８ｓｍ＋４４ｓｔｔ,染色体臂数ＮＦ＝１５６。     

渤海秋汛对虾数量预报方法的研究

渤海秋汛对虾的数量预报，是我国渔业预报中比较成功的报例之一。本文简述了此项预报工作的发展过程，介绍取得预报指标——相对资源量的原则和方法、加权系数的推算以及对各种回归方程的预报效果的检验结果，提出了针对不同资源水平的预报计算方法。此外，还对有争议的预报中的渔捞努力量因素问题进行了讨论。     

淡水池塘主养鲈试验

报道了首次利用淡水鱼塘,主养鲈兼养鲢,鲤,草鱼等试验,每亩放苗５１５尾,鲈占放养总重的７１．７％;主喂冷冻青鳞鱼,约占７７．７％,辅喂人工配饵;前期只充渗漏水,中后期透明度小于３０ｃｍ时,大量换水。结果：共产商品鱼８８０２ｋｇ,其中鲈３７４０ｋｇ,折合亩产１２４．７ｋｇ,成活率８９％。总产值１２８０４６．８地,纯利７６９６９．８地,平均亩纯利２５６５元,投入产出比１：２．５。     

Molecular identification and genetic analysis for 24 turf-type Cynodon cultivars by Sequence-Related Amplified Polymorphism markers

Bermudagrass (Cynodon ssp.) germplasm is genetically diverse and widely distributed in the world. The study was conducted to identify and assess the molecular variation and relationship among 24 cultivars developed in China, Australia and the USA. Sequence-Related Amplified Polymorphism (SRAP) was applied to cultivars identification in this study for the first time. Thirty of the 90 SRAP primer combinations generated a total of 274 clearly bands encompassing 249 (91%) polymorphic. Each bermudagrass cultivar has its unique binary code and can be distinguished from the others. Three distinct clusters were obtained by unweighted pair-group method with arithmetic averages based on the polymorphic markers. Coefficients of genetic distance among the genotypes ranged from 0.57 to 0.97. The results demonstrated that SRAP marker is a stable molecular marker technique for the identification of bermudagrass cultivars and their genetic relationships.