微生态制剂在鲟鱼工厂化养殖中的应用

循环水工厂化养殖过程中由于饲养的高密度和丰富的饵料投入会产生大量代谢污染物,随之也带来了养殖排放废水对环境的污染,长期以来存在氨氮、亚硝酸盐总量不断积累的问题,影响鲟鱼品质和产量。微生态制剂是从天然环境中筛选出来的微生物,具有促生长、无毒副作用,能消除养殖水体中的氨氮、亚硝酸盐、硫化氢等有害污染物,维持养殖系统中微生物的生态平衡,改善水质及水体环境。利用微生态制剂对养殖水体进行调控,对养殖鲟鱼实行全程质量控制管理,生产出无公害、无污染的优质鲟鱼产品。     

人工感染维氏气单胞菌对杂交鲟体内组织抗菌肽含量的影响

为探究抗菌肽在鲟鱼体内的表达规律,试验采用维氏气单胞菌人工感染杂交鲟后,采集不同时间段杂交鲟的肝脏、脾脏、心脏、肌肉、肠道、鳃6个组织样品,利用ELISA方法进行抗菌肽含量的检测。结果:(1)正常对照组杂交鲟6个组织中均有抗菌肽表达,在鳃和肠道组织中含量最高,在肝脏中含量最低。(2)与正常对照组比较,人工感染组杂交鲟6个组织中抗菌肽含量在不同时间段均明显升高,差异显著(P<0.05)。其中:在24 h和96 h鳃和肠道的抗菌肽含量差异极显著(P<0.01);在48 h肝脏、肌肉、心脏、脾脏的抗菌肽含量差异极显著(P<0.01)。结论:杂交鲟可能是通过抗菌肽来抵御细菌感染,这为杂交鲟细菌性疾病的防治提供了新思路。     

黑鱼子酱加工副产品在中餐中的应用探析

黑鱼子酱是由鲟鱼卵腌渍而成,是我国鲟鱼养殖基地的主导盈利产品,副产品包括鲟鱼皮、鲟鱼肠、鲟鱼骨、鲟鱼鳍、鲟鱼肚和鲟鱼肉等。鲟鱼骨富含硫酸软骨素,可采用多种烹调方式加工;鲟鱼翅和鲟鱼肚以焖、炖为主;鲟鱼肉富含优质蛋白质和脂类,有多种传统及风味菜肴。黑鱼子酱加工副产品的鲟鱼肉为分割速冻产品,既可采用传统的各种中餐烹调方式,也可借鉴西餐中烤、煎的方式,制作出多种类型的菜肴。大力开发黑鱼子酱加工副产品在中餐中的应用,为鲟鱼的综合运用提供一条新的思路。     

Renal -gulono-1,4-lactone oxidase activity as affected by dietary ascorbic acid in lake sturgeon (Acipenser fulvescens)

Sturgeon can synthesize -ascorbic acid (vitamin C) as they possess in their kidney -gulono-1,4-lactone oxidase, the enzyme catalyzing the last step of AA biosynthesis. The effect of increasing dietary ascorbic acid on gulonolactone oxidase activity was studied in lake sturgeon. Two-year-old lake sturgeon (body weight 253±89 g) were fed in triplicate groups with casein-based semipurified diets supplemented with either 0, 50, 250 or 1250 mg ascorbic acid/kg in the form of ascorbyl-2-monophosphate Mg for 38 days at 19.8°C. At the end of the trial, there were no significant differences in growth rate and survival among groups. Tissue total ascorbic acid concentrations increased significantly with dietary ascorbic acid. Renal gulonolactone oxidase activity was inconsistently affected by dietary treatment. These results suggested that, in sturgeon kidney unlike in the livers of ascorbic acid-synthesizing mammals, dietary ascorbic acid did not exert a negative feedback control on gulonolactone oxidase activity and thus on ascorbic acid synthesized. Using in vitro kinetics data we estimated a theoretical biosynthetic rate of ascorbic acid of 17 μmol (or 3 mg) per kilogram body weight per day at 15°C in juvenile lake sturgeon.     

Oxygen consumption rates of white sturgeon under commercial culture conditions

Oxygen consumption rates of white sturgeon (Acipenser transmontanus) were measured under commercial culture conditions. Mean fish size ranged from 0.09 to 3.8 kg (0.2–8.4 lbs). Mean daily values of oxygen consumption rates ranged from 70–330 mg kg fish⁻¹ h⁻¹. Peak oxygen consumption rates were measured to be as much as twice the mean daily values and were seen to occur in response to feeding for fish fed a ration of less than 2.6% body mass per day. With higher feed rations, peak oxygen consumption rates were a smaller percentage of the mean daily value. Multiple regression analysis showed that 93% of the variations in measured oxygen consumption rate values could be attributed to variations in feed ration.     

南方人工养殖达氏鲟心外膜囊肿症的组织病理研究

本文针对我国南方人工养殖达氏鲟(Acipenser dabrganus)高温期发生死亡现象，研究患病鱼的病理组织，通过解剖观察：患病鱼心外膜囊肿、形成大小不一的瘤状突起，囊内有水样物质；肝脏淤血、胆囊肿大；组织细胞病理研究结果表明：心外膜细胞坏死、溶解，发生脂肪质增生，心外膜囊肿腔内及心肌出现炎性细胞浸润，毛细血管构成网状结构；部分肝细胞坏死形成巢性病灶，并出现吞噬细胞群；肾脏的尿细管上皮细胞坏死、溶解，发生颗粒变性，尿细管腔内有脱落的尿细管上皮细胞；运用电子显微镜综合研究各脏器的病灶细胞组织，均未发现病毒、细菌、寄生虫等病原体。初步认为：心外膜囊肿病变、心脏功能的衰退、血液循环障碍、肾脏尿细管上皮细胞坏死是致死的主要原因；持续的高温和水质不良与致病有密切的关系。     

Calculation of protein and energy requirements in beluga sturgeon (Huso huso) using a factorial approach

This study tried to determine the protein and energy requirements of growing beluga sturgeon Huso huso using a factorial approach. The experiment was composed of four small‐scale growth trails covering different weight ranges. The fish fed at 0, 20, 40, 60, 80 and 100% of satiation. DWG had a steady increase throughout the experiment following a non‐linear equation as Y = 1.433 (±0.056) × Ln(X) ?2.740 (±0.261); r² = 0.99, p < 0.001, where Y = weight gain (g/day) and X = fish weight (g). The daily requirement of digestible energy (DE) for maintenance amounted to 79.09 kJ × BW (kg)^0.8. The daily requirement of DP for maintenance calculated as 0.93 g × BW (kg)^0.7. The relationship between DE intake (X) and DE gain (Y) expressed as Y = ?0.0004 (±0.000) X² + 0.600 (±0.082) X ?44.95 (± 6.72). Also, the relationship between DP intake (X) and protein gain (Y) was expressed as Y = ?0.019 (±0.006) X² + 0.548 (±0.062) X ? 0.498 (±0.121). The daily requirements of energy and protein were estimated as 79.09 kJ × BW (kg)^0.8 + 2.94 × DE gain and 0.93 g × BW (kg)^0.7 + 2.63 × DP gain. Apparently, beluga sturgeon is inefficient in converting energy and protein into body tissue. Therefore, energy content of the diet should be sufficiently high to satisfy large energy demands in beluga sturgeon and also to reduce the catabolism of protein.     

黑龙江施氏鲟繁殖群体结构现状调查

2010年5月10日-6月20日对黑龙江同江至抚远江段的施氏鲟（Acipenser schrencki）捕捞群体结构进行调查,测量施氏鲟90尾,全长为96～201（150.53±18.93）cm;其中雌性个体全长为 113～201（163.14±22.24）cm;雄性个体全长为96～183（138.48 ±20.55）cm。体重为3～44（18.46±10.17）kg;其中雌性个体体重为7.5～44（24.48±10.33）kg;雄性个体体重为3～30.5（12.70±5.94）kg。繁殖群体的雌雄比例为1:1.05;以16～20龄个体为主,占捕捞群体的37.2%;优势群体在11～25龄,占总群体的84.7%。繁殖群体中雌性的生长方程为:Y=0.00129x3.3169 ,R2=0.9202 ,雄性的生长方程为: Y=0.0029X3.0899, ;R2=0.9375 。     

First genetic characterization of sturgeon mimiviruses in Ukraine

A group of pathogenic nucleocytoplasmic large DNA viruses (NCLDVs) related to the Mimiviridae family infect farmed sturgeons across Europe, causing mild-to-severe losses. One of these viruses, Acipenser iridovirus-European (AcIV-E), was identified in six sturgeon species. During the 2018–2019 period, nine sick Siberian (A. baerii) and Russian (A. gueldenstaedtii) sturgeons were sampled in Ukrainian farms and tested for the presence of AcIV-E using real-time PCR. The presence of AcIV-E was confirmed in some samples. High-resolution melting (HRM) assay and Sanger sequencing demonstrated the presence in three farms of two alleles of the major capsid protein (MCP) gene, called var1 and var2. Five samples carried both var1 and var2 at varying ratios, and the sixth sample was infected with only var1. These results constitute the first detection of AcIV-E in Ukraine and the first detection of a sample carrying only var1. The full-length sequences of the MCP genes confirmed the existence of two genetic lineages of AcIV-E, tentatively named V1 and V2, each displaying multiple substitutions in the MCP gene. Some of the MCP sequences showed a genetic relationship to both V1 and V2 lineages, depending on the fragment examined. Most likely, these sequences resulted from recombination events.     

鲟鱼苗种微粒饲料开口养殖试验

在鲟鱼苗种培育转食阶段,多采用先喂活饵,再逐渐驯食投喂人工配合饲料的方法进行转食.利用地下河水进行杂交鲟鱼苗种流水养殖,直接采用微粒饲料进行鲟鱼苗开口,苗种成活率为74.0%,饵料系数为1.31,平均单产为23.64 kg/m2,投入产出比1:2.12,养殖成本为17.9元/kg,取得较好养殖效果,证明利用微粒饲料直接开口饲养是可行的.