巨大芽孢杆菌MPF-906对养鱼水质净化的初步研究

以鲫鱼为对象,利用从水产养殖水体中分离得到的巨大芽孢杆菌MPF-906,研究了其微生态制剂同步净化养鱼水质的动态变化。结果显示,在水族箱中添加巨大芽孢杆菌MPF-906制剂后,与对照组相比,水中的亚硝酸盐显著降解,COD也有所下降,pH值稳定在7.78￣8.19之间,表明巨大芽孢杆菌微生态制剂对净化养鱼水质和调节养殖水体微生态结构稳定具有明显的作用,其最适使用浓度为4×108CFU/mL。     

A reovirus disease in cultured mud crab, Scylla serrata, in southern China

A reovirus, designated mud crab reovirus (MCRV), associated with large economic losses was recently isolated from marine cultured mud crab, Scylla serrata, in southern China. The complete viral particle is 70 nm in diameter, icosahedral and non-enveloped. The virus infects connective tissue cells of the hepatopancreas, gills and intestine in mud crab and develops in the cytoplasm. Hundred per cent mortality was observed in mud crab experimentally infected by intramuscular injection, bath inoculation and oral inoculation, while cohabitation infection caused 80% mortality. The viral genome consists of 13 linear dsRNA segments, with an electrophoretic pattern 1/5/7. The results of this study suggest that the virus is highly pathogenic and can be transmitted enterically as well as via the body surface of mud crab. Although the genomic organization of this virus is different from that of the other crab reoviruses, CcRV-W2 and DpPV, all three of these reoviruses have similar electrophoresis patterns. Therefore, MCRV may be a new member of the DpPV and CcRV-W2 group.     

The impact of net-isolated polyculture of tilapia (<Emphasis Type="Italic">Oreochromis niloticus</Emphasis>) on plankton community in saline–alkaline pond of shrimp (<Emphasis Type="Italic">Penaeus vannamei</Emphasis>)

We used 12 land-based experimental enclosures (6 m × 5 m) in a saline–alkaline pond of shrimp (Penaeus vannamei) to determine the impact of net-isolated polyculture of tilapia (Oreochromis niloticus) on plankton communities for 40 days. Tilapias were stocked in net cages suspended in enclosures, in polyculture ponds including tilapia and shrimp. Four tilapia biomass were tested: 0, 39, 115 and 227 g m⁻². Shrimp stocking biomass were 0.7 g m⁻² in all treatments. There were three replicates in each treatment. Our results showed that the presence of tilapia significantly reduced phytoplankton biomass directly through predation and indirectly through top-down effect. The stocking of tilapia reduced zooplankton biomass, particularly rotifer biomass. However, copepod biomass was not been significantly affected. So, net-isolated polyculture of tilapia can thus have a strong impact on phytoplankton allowing the co-existence of large numbers of copepods with planktivorous fish and improving the water quality of shrimp ponds.     

癸甲溴铵对褐牙鲆的急性毒性及抑菌试验

通过药浴方式,进行了癸甲溴铵对褐牙鲆的急性毒性试验;采用二倍稀释法,进行了癸甲溴铵对鳗弧菌、副溶血弧菌的体外抑菌试验;探讨了癸甲溴铵对鳗弧菌引起的褐牙鲆细菌性疾病的防治效果。结果表明,在19.0～21.0℃和24.5～25.5℃时,癸甲溴铵对褐牙鲆的24、48h半数致死浓度(LC50)和安全浓度(Sc)分别为6.35、4.84、0.84和2.43、2.14、0.5mg/L。通过对中毒死亡褐牙鲆的病理组织学观察表明,癸甲溴铵对褐牙鲆的鳃损害最严重,其次是肝脏,对肾脏的损害相对较轻,特别是对鳃的损害与鱼的死亡有很大的关系。在24和32℃,癸甲溴铵对鳗弧菌、副溶血弧菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)分别为10、20和5、10mg/L。防治效果试验表明,癸甲溴铵0.3mg/L浓度药浴可有效防治鳗弧菌引起的褐牙鲆细菌性疾病。     

The effects of dietary fermented wheat bran polysaccharides on mucosal and serum immune parameters,hepatopancreas antioxidant indicators,and immune-related gene expression of common carp (Cyprinus carpio) juveniles

Aquaculture research has focused on polysaccharides as they are among the most promising new-generation immunostimulant used to control aquatic diseases. The aim of this study was to investigate the immunomodulatory effects of fermented wheat bran polysaccharides (FWBPs) on juvenile common carp (Cyprinus carpio). Carps were fed different FWBP amounts (0%, 0.1%, 0.2%, and 0.4%) for 8 weeks and then their skin mucus and serum immune parameters, hepatopancreas antioxidant indicators, and immune-related gene expression in the intestines, kidneys, and spleen were measured. The skin mucus IgM levels significantly increased in 0.1% FWBP group, but decreased in 0.4% FWBP group. The skin mucus protease and the serum alkaline phosphatase activities increased significantly in the 0.2%, 0.1%, and 0.4% FWBP groups, respectively. The serum total Ig levels increased noticeably in the 0.1% and 0.2% FWBP groups. The highest and lowest serum lysozyme activities were observed in the 0.1% and 0.4% FWBP groups, respectively. The hepatopancreatic total superoxide dismutase activity was higher in the 0.1% FWBP group than in the control. The malondialdehyde levels decreased significantly in the 0.2% and 0.4% groups. The intestinal mRNA levels of the LZM-C and IL-10 genes were significantly higher in the 0.2% than in the 0.4% FWBP group; TNF-α was significantly upregulated in the 0.1% group. The gene expression in the kidneys did not differ significantly among the treatments, except for a significant increase in the IL-10 expression in the 0.1% treatment. Significantly elevated expression of LZM-C in 0.2% group and IL-10 in 0.1% group was observed in the spleens. TNF-α and IL-1β were significantly downregulated in the 0.4% group. These results suggest that FWBPs could be used as immunostimulant feed additives in common carp cultures.

     

日本蟳幼体发育的研究

日本蟳Charybdis(charybdis)Japonica(A.Milne-Edwards)是我国大型海产食用蟹类之一。它遍布我国、日本、朝鲜和马来西亚沿岸,红海等亦有分布。关于日本蟳幼体发育的研究,Aikawa(1937)曾观察了第1期溞状幼体,Kurata和Nishina(1975)观察到第4期溞状幼体;八塚刚(1952、1957、1962)和寺田正之(1979)也曾对日本蟳的溞状幼体进行过描述,而我国沿海日本蟳发育,迄今未见研究报告。笔者自1984年7月,开始了日本蟳的室内人工繁殖和幼体培育,并培养出第1期幼蟹,85年又对各期幼体的发育形态进行了系统的观察和研究。现将结果整理如下。     

Requirement of vitamin E of growing sea cucumber Apostichopus japonicus Selenka

This feeding trial was conducted to determine the vitamin E requirement of growing sea cucumber Apostichopus japonicus Selenka. Six isonitrogenous and isoenergetic experimental diets were formulated to contain graded levels of vitamin E (6.7, 81.2, 159.3, 237.8, 314.6, 395.9 mg/kg diet). Each diet was assigned randomly to 30 growing sea cucumber with initial body weight 15.43 g in triplicates for 8 weeks. Survival rate was not affected by dietary vitamin E; meanwhile, both the weight gain (WG) and specific growth rate were presented the trend of increasing first and then kept stable. With the increasing of dietary vitamin E, crude lipid content of body wall was evaluated firstly and dropped afterwards. When dietary vitamin E contents were lower than 159.3 mg/kg, vitamin E contents of body wall were increased by dietary vitamin E levels, but there were no more differences when dietary vitamin E higher than 159.3 mg/kg. There were minor effects on digestive enzymes of intestine by dietary vitamin E. Contents of malondialdehyde were decreased, while the total superoxide dismutase activity was increased first and then decreased with the increasing of dietary vitamin E. Activities of intestinal alkaline phosphatase were increased, and glutamic oxaloacetic transaminase were decreased first and then increased with the increasing of dietary vitamin E. In conclusion, analysis by a linear regression equation of WG or vitamin E contents in body wall indicated that the optimum requirement of vitamin E for growing sea cucumber (initial body weight 15.43 g) was 165.2–187.2 mg/kg diet.     

兴凯湖大白鱼人工繁殖及胚胎发育研究

2019年6月,通过人工催产获得兴凯湖大白鱼受精卵,系统地观察了胚胎发育的全过程。结果表明,在池塘养殖的条件下,人工养殖可获得成熟的亲鱼,人工催产获得的兴凯湖大白鱼的受精卵为圆球型,呈青灰色或黄绿色。平均卵直径为0.78 mm(0.65～1.02 mm),吸水后平均卵直径为4.02 mm。胚胎发育过程可分为23个阶段。在24.5～26.8℃范围内,受精42 min后开始第一次卵裂,受精10 h 45 min后开始形成器官。胚胎发育的总积温为486.98℃·h。     

水产品等食品中磺胺类抗生素残留分析与预处理方法的研究进展

对水产品等食品中磺胺类抗生素常用的分析方法和预处理方法进行了综述,归纳和比较了毛细管电泳法、微生物方法、液相色谱-质谱法、免疫法、气相色谱法、分光光度法、高效液相色谱法等特点。其中高效液相色谱法由于操作简便、快速、灵敏、准确的特点,是当前检测磺胺类抗生素的主要方法。同时,对包括固相萃取、分子印迹等预处理方法进行了综述。     

Production, disinfection and evaluation for aquaculture applications of rotifer resting eggs from Bohai Bay, P.R. of China

The dynamics of resting egg production of the rotifer Brachionus plicatilis originating from a wild population in the Tanggu Saltworks (P.R. China) was investigated. In the natural environment as well as in semi-controlled rearing conditions an increased resting egg production was noticed with declining food availability. Processed resting eggs had a hatching efficiency of 3 x 10 6 rotifers per gramme irrespective of their origin. Hatching started 22 h after the initiation of incubation and was completed after 36 h. Rotifers obtained from resting eggs could be further cultured on Culture Selco® and enriched with Super Selco®. The fatty acid profile of these rotifers were not divergent from reference rotifers (originating from the Laboratory of Aquaculture and Artemia Reference Centre) demonstrating that this strain was not catabolizing essential fatty acids and could be used for enrichment purposes. Storage of resting eggs at 4°C resulted in a 50% lower hatching after 1 year but remained stable during the next 2 years. The resting eggs used for storage could easily be disinfected without affecting their hatching characteristics. These results indicate that this material could be used as inocula for mass cultures of live food for commercial hatcheries.