白斑综合征病毒在养殖克氏原螯虾中感染流行研究

2007年,在从南京采集的患病养殖克氏原螯虾样品超薄切片中发现大量类似对虾白斑综合征病毒(WSSV)颗粒,结合初步的流行病学调查、人工回感实验及PCR检测结果确定导致此次养殖克氏原螯虾大规模死亡的病原为WSSV。利用建立的特异性引物PCR方法,在江苏省内扬州邵伯湖、淮安白马湖、盱眙、南京禄口等多处养殖克氏原螯虾体内均检测到该病毒,且在鳃、心肌、神经、肝脏、肠道、肌肉等多处组织中被检出;未检测到另外两种常见对虾病毒:桃拉病毒(TSV)和传染性皮下及造血组织坏死病毒(IHHNV)。     

克氏原螯虾同步化与非同步化育苗效果分析

[目的]为不同规模的克氏原螯虾养殖单位提供相应的育苗技术。[方法]利用克氏原螯虾秋冬季节生殖需要一定水位的生态习性,采用降低育苗池水位的方法同步化培育苗种,并与非同步化育苗技术的效果进行比较。[结果]同步化育苗的苗种规格较小,但能在同一时间内获得规格较整齐的苗种,适合大规模养殖单位同期进苗。非同步化育苗的苗种规格较大,能在夏季养成商品虾提早上市,但无法获得大量规格整齐的苗种,只能分期分批获得不同规格的苗种,适合在不同时期供应小规模的养殖单位。同步化育苗累计出苗尾数、出苗重量和商品虾收获重量分别是非同步化育苗的1.78、0.93、0.80倍。[结论]同步化育苗能满足大规模养殖单位的需要;非同步化育苗可以不断收获苗种和商品虾,能满足小规模养殖单位的需要。     

利用生物絮团技术对克氏原螯虾的养殖效果初探

为探究将生物絮团技术应用到克氏原螯虾养殖的可能性,本实验利用生物絮团技术和普通饲料投喂2种方式短期养殖体质量为(9.70±0.32) g的克氏原螯虾30 d。比较养殖期间2实验组的水化学指标以及实验结束时2实验组幼虾的生长情况,肌肉及肝胰腺营养成分组成,胃、肠和肝胰腺组织的消化酶活性,肝胰腺和肌肉组织的抗氧化能力。结果显示,①在养殖期间,絮团组水体总氮(TN)、亚硝态氮(NO₂^--N)、硝态氮(NO₃^--N)的质量浓度均维持在较低的水平。②本实验条件下2实验组虾的终末体质量、增重率(WG)、特定生长率(SGR)、存活率(SR)均无显著差异。③絮团的粗蛋白含量可以达到36.8%,能够满足克氏原螯虾对于蛋白的需求。但絮团的粗脂肪含量较低,这也影响了絮团组幼虾肌肉组织的粗脂肪沉积量。④絮团组幼虾肝胰腺中α-淀粉酶(α-AL)、脂肪酶(LPS)、纤维素酶(CL)活性均显著高于饲料组幼虾,而饲料组幼虾在胃、肠组织中的α-AL活性较高,2实验组幼虾的胃蛋白酶活性无明显差异。⑤絮团组幼虾的抗氧化能力与饲料组幼虾相比,肝胰腺中超氧化物歧化酶(SOD)活性较高,丙二醛(MDA)含量较低,但总抗氧化能力(T-AOC)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)以及溶菌酶(LZM)无明显差异。研究表明,生物絮团技术在克氏原螯虾的养殖中具有积极作用,可以达到与饲料投喂相同甚至更好的养殖效果。     

饲料脂肪水平对克氏原螯虾亲虾生长性能、肌肉成分、繁殖性能以及血淋巴生化指标的影响

为研究克氏原螯虾亲虾对脂肪的需要量,本实验采用初始体质量为(15.46±0.20)g的克氏原螯虾亲虾324尾,分为6组(每组设置3个重复,每个重复18尾,雌雄比例为2:1),投喂粗蛋白质水平为30%,脂肪水平分别为1.98%(对照组)、4.12%、5.84%、7.89%、10.48%和11.89%的6组半精制饲料,饲养8周后,测定并分析亲虾的生长性能、肌肉成分、繁殖性能、肝胰腺消化酶活性以及血淋巴部分生化指标。结果发现:①随着饲料脂肪水平的升高,增重率和特定生长率先上升,在饲料脂肪水平达到7.89%后呈下降趋势;饲料系数和肝体比呈上升趋势,11.89%组最高。②饲料脂肪水平对亲虾肌肉水分和灰分含量无显著影响;随着饲料脂肪水平的升高,肌肉粗脂肪含量呈现先升高后降低最后趋于稳定的趋势,在饲料脂肪水平为5.84%时最高。③随着饲料脂肪水平的升高,性腺指数、抱卵率、抱卵量均呈现先上升后降低的变化规律,均在饲料脂肪水平为7.89%时达到最大。④血淋巴中总蛋白含量随饲料脂肪水平呈现先下降后上升趋势;谷草转氨酶、谷丙转氨酶活性均随饲料脂肪水平升高而升高,均在11.89%组最高;血淋巴中葡萄糖含量各组间无显著性差异。⑤饲料脂肪水平对实验虾肝胰腺蛋白酶和脂肪酶活性有显著影响,对淀粉酶活性无显著性影响。利用增重率与饲料脂肪水平进行折线回归分析,克氏原螯虾亲虾获得最佳增重率时对饲料的脂肪需要量为7.60%。对实验虾生长性能、肌肉成分、繁殖性能、肝胰腺消化酶活性、血淋巴生化指标进行综合分析,显示本实验条件下克氏原螯虾亲虾对脂肪需要量为7.60%～7.89%。     

溴氰菊酯对克氏原螯虾的氧化胁迫效应

为了解溴氰菊酯对克氏原螯虾的毒性及致毒机理,采用24h换水式生物试验研究了溴氰菊酯对克氏原螯虾的96h急性毒性,分光光度法检测了6、12、24和48h后0.01、0.02和0.04μg/L溴氰菊酯对肝胰腺超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活力和丙二醛(MDA)的含量等氧化胁迫相关指标的影响。结果表明,24、48和96h的半致死浓度分别为0.1560、0.0993和0.0562μg/L,安全浓度为5.62ng/L;在整个暴露过程中,溴氰菊酯各个处理组都引起了氧化胁迫相关指标的变化。SOD和CAT活力的变化趋势相同,都呈抑制-诱导-抑制的变化规律,MDA含量则一直高于对照组。暴露6h后,0.01μg/L浓度组MDA含量极显著高于对照组(P<0.01),0.04μg/L浓度组MDA含量约为对照组的1.98倍(P<0.05);暴露12h后,MDA仍保持较高水平,0.02μg/L浓度组MDA含量约为对照组的1.76倍(P<0.05);暴露24h后,各浓度组CAT活力分别比对照组上升了70.98%、73.05%和66.67%(P<0.01);暴露48h后,0.01、0.02μg/L浓度组的SOD活力分别下降了...     

Cu2+和Cd2+对克氏原螯虾幼虾的毒性效应研究

采用静水法生物测试,研究了Cu2+和Cd2+对克氏原螯虾幼虾(体重0 0142～0 0308 g)的急性毒性作用.试验结果表明,克氏原螯虾对Cu2+、Cd2+均会产生较强的毒性效应,其对Cu2+、Cd2+的耐受性随接触时间延长而明显降低.Cu2+对克氏原螯虾幼虾24 h、48 h半致死浓度(LC50)分别为30.854 mg/L、10.595 mg/L;Cd2+对克氏原螯虾幼虾24 h、48 h、72 h半致死浓度(LC50)分别为5.315 mg/L、1.371 mg/L和0.414 mg/L.Cu2+、Cd2+对其的安全浓度(SC)分别为0.375 mg/L、0.027 mg/L,为相应渔业水质标准的3.8倍和 5.5倍,表明克氏原螯虾具有较强耐受Cu2+和Cd2+污染的能力.     

Correlation Analysis for Feeding Habits,Morphological Parameters,Weight Parameters and Abdomen Meat Percentage of Procambarus clarkii北大核心CSCD

This experiment was conducted to determine the food source and trophic level of Procambarus clarkii from rice-crayfish field by stable isotope method, and to analyze the correlation between feeding habits, morphology parameters, weight parameters and abdomen meat percentage of P. clarkii. normal (62 individuals) and claw reborned (6 individuals) samples of P. clarkii were collected from the rice-crayfish continuous production field in Zhanjiang. At the same time, vascular plants, snails, as well as diet samples were collected. The stable carbon and nitrogen isotope values of all collected samples were analyzed, the contribution rate of diet, Elodea nuttallii and Potamogeton crispus to the abdomen meat growth of P. clarkii were calculated using a stable isotope mixing model including element concentration, and the trophic levels of P. clarkii and Pomacea canaliculata were calculated by stable nitrogen isotope model. The correlation between stable carbon and nitrogen isotope characteristics (δ13 C and δ15 N) of abdomen meat, morphological parameters (body length, full length, carapace length, carapace width, tail fan length) and weight parameters (body weight, abdomen meat weight, claw weight, claw body ratio) of the collected crayfish were analyzed. The results showed as follows: 1) the collected crayfish included 30 female and 32 male individuals, and the body weight of these crayfish ranged from 3.40 to 29.35 g, average (14.05±6.26) g. The model calculation results showed that diet contributed 63.40% of biomass, 62.28% of carbon and 75.15% of nitrogen to the abdomen meat growth of P. clarkii. 2) In this study, Cipangopaludina cahayensis was used as the baseline for primary consumers, and the calculated trophic level of P. clarkii was 2.20, while the trophic level of P. canaliculata was 2.68. 3) The abdomen meat percentage of P. clarkii (<15 g) collected were extremely negatively correlated with the claw weight and the claw body ratio (P<0.01), indicated that the growth of the claws directly affected the muscle growth of these crayfish. The abdomen meat percentage of P. clarkii (>15 g) were not significantly correlated with the claw weight and the claw body ratio (P > 0. 05), but were extremely positively correlated with the abdomen meat weight and the δ13C value (P<0.01) . It showed that the utilization of diet by these crayfish had become a key factor in determining their abdomen meat percentage. 4) There was a significant negative correlation between the claw weight and the δ13C value (P<0.05) in all collected normal crayfish. It could be inferred that individuals with well-developed claws tend to eat more P. crispus which with lower δ13C value. When the diet was sufficient, the lack of claws did not significantly affect the feeding and growth of P. clarkii (P<0.05) . It is concluded that there are significant correlation between feeding habits, morphology parameters, weight parameters, and abdomen meat percentage of P. clarkii, the diet is the main nutrient source for the abdominal muscle growth of P. clarkii in this study, but even when the diet is sufficient, P. clarkii still feeds heavily on aquatic plants. Traditional methods of stable nitrogen isotope trophic level study may not suitable for aquaculture ecosystems which are strongly influenced by diets. The results of this study can provide basic data for the genetic selection of P. clarkii and the ecological research on the integrated breeding model of rice-crayfish. © 2023 Chinese Journal of Animal Nutrition. All rights reserved.     

牛磺酸对克氏原螯虾生长性能、非特异性免疫以及肝胰脏抗氧化能力的影响

为了探讨牛磺酸对克氏原螯虾(Procambarus clarkii)生长性能、非特异性免疫以及肝胰脏抗氧化能力的影响。以300只初始体重为(4.50±0.50) g的克氏原螯虾为对象,随机分成5组,分别投喂5种不同牛磺酸含量的等氮等能饲料,投喂4周后,测定各组生长指标、血液和肝胰脏的生化指标。实验结果表明,200、300 mg/kg组克氏原螯虾的增重率、出肉率,血清总蛋白(TP)、溶菌酶(LSZ)以及肝胰脏超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活性,均高于对照组,具有统计学意义(P<0.05);200、300 mg/kg组克氏原螯虾的血清谷丙转氨酶(GPT)和谷草转氨酶(GOT)的活性均低于对照组,具有统计学意义(P<0.05);其中300 mg/kg组克氏原螯虾的成活率和肝胰脏谷胱甘肽(GSH-Px)的活性高于对照组,饵料系数低于对照组,均具有统计学意义(P<0.05);而肝胰脏丙二醛(MDA)的含量在各组间差异不具有统计学意义。因此,在饲料中添加200~300 mg/kg的牛磺酸可以促进克氏原螯虾的生长,提高虾体的非特异性免疫力和肝胰脏抗氧化能力,增强虾体的抗病力。     

信阳市不同来源小龙虾中的重金属水平评价

测定了信阳市6种不同来源小龙虾中甲基汞、镉、铬、铅和无机砷的含量,并根据单因子污染指数评价法对小龙虾的品质进行质量安全评价.结果表明,除工业区小龙虾Cr含量超出PHMSO标准外,其余均未超出相关标准.但单因子污染指数评价法表明,来自工业区、污水沟和茶叶生产区的小龙虾均受到了轻度或中度的重金属污染.     

克氏螯虾的营养需求研究及饲料应用展望

克氏螯虾来自美洲,目前已成为我国重要的特种水产养殖品种,由于它的生物学和经济学价值,对克氏螯虾营养需求及饲养方面的研究已逐步开展。文中就克氏螯虾对蛋白质、脂肪、糖类、氨基酸、矿物元素和维生素等营养素需求及相关的摄食量、消化利用率方面的研究成果进行综述和比较分析,并对克氏螯虾人工配合饲料的应用进行前景展望。