Parentage testing for hatchery-produced abalone <Emphasis Type="Italic">Haliotis discus hannai</Emphasis> based on microsatellite markers: preliminary evaluation of early growth of selected strains in mixed family farming

This study dealt with the detection of parentage in a mixed family tank of abalone Haliotis discus hannai using microsatellite DNA markers. As a preliminary investigation, the early growth rate between selected and non-selected abalone families, which were reared together in the mixed family tank from settlement stage to juvenile stage (7 months of age), was also compared. The selected families were derived from seven parents (three females and four males) selected for larger size in shell length at about 1-year-old, and the non-selected families originated from five wild captives (three females and two males). Parentage analysis based on eight microsatellite markers unambiguously allocated the 170 juveniles sampled from the single tank to the 17 parental pairs. The family size was highly heterogeneous among families, as two males in the selected families and one male in the non-selected families dominated the contribution to the offspring pool (>80%). The mean shell length of the selected families was approximately 23% larger than that of the non-selected families (Student’s t-test, P<0.001). This study demonstrated that the use of microsatellite markers is effective for parentage determination in the mixed family farming, commonly used in abalone hatcheries, and selective operations for larger size could improve the growth of the next generation.     

“零排放”复合生物净化模式用于循环水养鲍系统的试验研究

采用水生植物滤池(UB和PUB)和固定膜生物滤池（SB）的复合净化模式，对鲍鱼养殖水体和系统排放水体进行净化，实现了循环水养鲍系统的清洁生产。试验结果表明，植物滤池UB对养殖水体中总氨氮(TAN)具有很高的吸收效率，从而降低了SB的硝化负荷，大大减少了TAN、NO^－₂-N、NO^－₃-N和COD的积累，在整个试验过程中，养殖水体中TAN、NO^－₂-N、NO^－₃-N和COD的浓度分别低于0.19、0.01、1.75和1.20 mg/L。由于UB滤池的吸收作用和SB的硝化作用，养殖水体中PO^3-₄的浓度一直保持在0.30 mg/L以下。另外，这种复合净化模式具有调节水体pH值的作用，在试验期间，养殖水体中的pH值一直保持在8.11～8.14的良好水质范围，对鲍鱼的养殖十分有利。系统排放水经另一植物滤池PUB吸收净化后，PO^3-₄浓度降至0.22 mg/L 以下，NO^-₃-N的浓度甚至降至0.10 mg/L以下。本文还建立了养殖循环水体中无机氮的循环模型，用于对养殖水体中TAN、NO^－₂-N和NO^－₃-N的预测和控制。     

总氨、亚硝酸氮及养鲍污水对皱纹盘鲍生长的影响

单因子总氨氮(TNH3-N)、亚硝酸氮(N02^--N)试验表明，当养鲍用水中非离子氨氮(NH3-N)为0．035mg／L以下或N02^--N为0．8mg／L以下时，对皱纹盘鲍Haliotis discus hannai Ino幼鲍的生长不产生明显影响；NH3-N对幼鲍生长产生影响的EC5(引起幼鲍生长速度减慢5％的浓度)为0．103mg／L，不产生影响的最大浓度为0．045mg／L。双因素试验结果表明，水中TNH3-N、N02^--N对幼鲍生长的影响没有交互作用，只是简单的相加作用。经回归表明，养鲍自污染水中，NH3-N是影响幼鲍生长的主要因子，它对幼鲍生长产生影响的EC5为0．022mg／L，不产生影响的最大浓度为0．0lmg／L，均比单因子试验结果显著降低。     

Substitution effect of sea tangle (ST) (Laminaria japonica) with tunic of sea squirt (SS) (Halocynthia roretzi) in diet on growth and carcass composition of juvenile abalone (Haliotis discus,Reeve 1846)

Substitution effect of sea tangle (ST) with tunic of sea squirt (SS) in diet on growth and carcass composition of juvenile abalone was determined. One thousand four hundred and seventy abalones were distributed into 21 containers. Six formulated diets in triplicate were prepared. A 200 g/kg ST was included into the ST0 diet. The 200, 400, 600, 800 and 1000 g/kg of ST were substituted with the same amount of tunic of SS, referred to as the ST200, ST400, ST600, ST800 and ST1000 diets, respectively. Finally, Undaria was prepared to compare effect of the formulated diets on performance of abalone. The experimental diets were fed to abalone for 16 weeks. Weight gain of abalone fed the ST400 diet was higher than that of abalone fed the ST0, ST600, ST800 and ST1000 diets and Undaria. Weight gain of abalone fed the formulated diets was higher than that of abalone fed the Undaria. The chemical composition of the carcass of abalone was affected by dietary substitution of ST with tunic of SS. In conclusion, ST could be completely substituted with tunic of SS without retardation in performance of abalone. Abalone fed the ST400 diet substituting 400 g/kg ST with tunic of SS achieved the best growth.     

Evaluation of Antiviral Effect against SARS-CoV-2 Propagation by Crude Polysaccharides from Seaweed and Abalone Viscera In Vitro

Crude polysaccharides, extracted from two seaweed species (Hizikia fusiforme and Sargassum horneri) and Haliotis discus hannai (abalone) viscera, were evaluated for their inhibitory effect against SARS-CoV-2 propagation. Plaque titration revealed that these crude polysaccharides efficiently inhibited SARS-CoV-2 propagation with IC₅₀ values ranging from 0.35 to 4.37 μg/mL. The crude polysaccharide of H. fusiforme showed the strongest antiviral effect, with IC₅₀ of 0.35 μg/mL, followed by S. horneri and abalone viscera with IC₅₀ of 0.56 and 4.37 μg/mL, respectively. In addition, immunofluorescence assay, western blot, and quantitative RT-PCR analysis verified that these polysaccharides could inhibit SARS-CoV-2 replication. In Vero E6 cells, treatment with these crude polysaccharides before or after viral infection strongly inhibited the expression level of SARS-CoV-2 spikes, nucleocapsid proteins, and RNA copies of RNA-dependent RNA-polymerase and nucleocapsid. These results show that these crude marine polysaccharides effectively inhibit SARS-CoV-2 propagation by interference with viral entry.     

鲍低氧胁迫响应机制的研究进展

鲍养殖业已成为我国海洋经济发展中的重要组成部分。近年来，因低氧胁迫，特别是高温低氧联合胁迫而导致的养殖鲍大规模死亡的现象时常发生，给鲍养殖业带来了严重的经济损失，已成为阻碍鲍养殖业健康可持续发展的重要环境因素。本文从鲍的生长、存活、生理生化指标 (包括心率、代谢、酶的活性、pH等)、免疫机能、胁迫响应基因及其表达调控等方面综述了鲍低氧胁迫响应机制的研究进展，以期为进一步研究鲍的低氧胁迫响应机制、开展鲍耐低氧新品种的选育等提供参考。此外，本文还提出了鲍低氧胁迫的预防调控措施，希望对养殖业者减少因夏季低氧胁迫诱发的养殖鲍大规模死亡而造成的损失有所帮助。     

不同鲍及其杂交种的营养成分与质构特性

绿盘鲍和西盘鲍作为经全国水产原种和良种审定委员会审定通过的水产新品种，在生长和耐高温性能上表现出显著优势，已在产业上广泛推广养殖，但其营养品质方面的研究尚不完善。本研究以这两个鲍新品种以及西氏鲍、皱纹盘鲍和绿鲍为对象，对其营养成分与质构特性进行了比较分析。结果显示，绿盘鲍的肥满度为(0.76±0.14) g/cm³，相较于其母本提高了35.71%，相较于其父本提高了72.73%；足肌的粗蛋白含量为62.26%±6.62%，相较于其母本提高了9.83%，相较于其父本提高了14.26%，因此在肥满度和粗蛋白含量方面，绿盘鲍具有明显的超亲杂种优势。5种鲍的脂肪酸营养价值为皱纹盘鲍>绿盘鲍>西盘鲍>绿鲍>西氏鲍，可见杂交种的脂肪酸营养具有中亲杂种优势。在质构指标上，西氏鲍的弹性和脆度最高，绿鲍脆度最低，杂交种各项质构指标都未表现出杂种优势。熵权法综合分析结果显示，皱纹盘鲍营养品质最优，绿盘鲍和绿鲍在风味上优于西氏鲍与西盘鲍。本研究结果将为未来鲍的品质育种及产品精深加工与开发提供技术支撑。     

沉箱养鲍

在风浪大的潮间带低潮区岩礁滩，用钢筋混凝土制成的筒形沉箱，内置小型鲍礁，进行九孔鲍的养殖。每个沉箱放长２ｃｍ左右的幼鲍８００￣１０００个，随着生长将其稀疏至５００个，喂以江篱、海带。经６￣８个的养殖壳长达５ｃｍ以上，成活率为７０％左右，每个沉箱产商品鲍１０￣１２ｋｇ。