壳聚糖对异育银鲫生长和消化酶的影响

以基础饲料为对照,以在基础饲料中分别添加0.125%、0.25%、0.5%、0.75%、1%的壳聚糖为实验饲料,饲养异育银鲫（Carassius auratus gibelio）60 d,与对照组比较生长、成活、饲料系数、蛋白质效率、鱼体营养成分、白肌RNA/DNA比值及肝胰脏、肠道的蛋白酶、淀粉酶活性.结果表明,本次实验所添加壳聚糖对异育银鲫的成活率、鱼体营养成分和白肌的RNA/DNA比值均无显著影响（P＞0.05）.添加0.5%、0.75%和1%壳聚糖可以显著提高异育银鲫的特定生长率和蛋白质效率,显著降低异育银鲫的饲料系数.添加0.5%壳聚糖可以显著提高异育银鲫肠道的淀粉酶活性;添加0.75%和1%壳聚糖可以显著提高肠道和肝胰脏的蛋白酶活性和肠道的淀粉酶活性.[中国水产科学,2006,13（3）：440-445]     

异育银鲫性别控制的研究

用含４００和８００ｐｐｍ １７α－甲基睾酮的饲料投饲孵化后３天的异主能银鲫仔鱼４５天，再用无激素的饲料饲养成年，结果获得了一批性腺呈细线状、难辨雌雄的中性不育鱼。经随机解剖测定，中性不育鱼的比例分别是对照组的３．７１和３．４０倍；与对照组比较，试验组的平均体重分别增长１６％和１１％，平均性腺系数分别降低４５．５％和２４．５％；平均出肉率分别增长６．５％和５．０％。切片观察未发现中性鱼的性腺内有生殖     

Pharmacokinetics of minocycline in crucian carp (Carassius auratus) after intravenous and oral administration

The pharmacokinetic of minocycline was studied after a single intravenous as well as oral dose (5 mg/kg body weight) in crucian carp (Carassius auratus) reared in freshwater at 10°C. Plasma samples were randomly collected from six fish at each sampling time. Plasma concentrations were determined by high‐performance liquid chromatography and further subjected to noncompartmental analysis. Initial concentration of minocycline just after intravenous administration was calculated as 7.320 μg/ml, while the other parameters after intravenous injection were determined as flows: apparent elimination rate constant (λ_z) of 0.064 per hr, apparent elimination half‐life () of 10.82 hr, total body clearance (Cl) of 142.72 ml/hr/kg, volume of distribution (Vz) of 2,227.38 ml/kg and volume of distribution at steady‐state (Vss) of 1,937.08 ml/kg. While after oral administration, the λ_z, , mean absorption time (MAT), absorption half‐life (t_1/2ka) and bioavailability were determined as 0.059 per hr, 11.74, 5.55, 3.84 hr, and 81.98%, respectively, and the peak concentration was observed as 1.474 ± 0.362 μg/ml at 8 hr. It was shown that minocycline was slowly but relatively completely absorbed, extensively distributed, and slowly eliminated in crucian carp. Based on the ratios of AUC_0–24 hr/MIC90, a minocycline dosage of 5 mg/kg body weight administered intravenously or orally would be only effective to successfully treat crucian carp infected by bacterium with MIC values ≤0.25 μg/ml.     

Rapid visual detection of cyprinid herpesvirus 2 by recombinase polymerase amplification combined with a lateral flow dipstick

Herpesviral haematopoietic necrosis (HVHN), caused by cyprinid herpesvirus 2 (CyHV‐2), causes significant losses in crucian carp (Carassius carassius) aquaculture. Rapid and convenient DNA assay detection of CyHV‐2 is useful for field diagnosis. Recombinase polymerase amplification (RPA) is a novel isothermal DNA amplification and detection technology that can amplify DNA within 30 min at ~37°C by simulating in vivo DNA recombination. Herein, a rapid and convenient detection assay based on RPA with a lateral flow dipstick (LFD) was developed for detecting CyHV‐2. The highly conserved ORF72 of CyHV‐2 was targeted by specific and sensitive primers and probes. The optimized assay takes only 15 min at 38°C using a water bath, with analysis of products by 2% agarose gel electrophoresis within 30 min. A simple lateral flow strip based on the unique probe in reaction buffer was developed for visualization. The entire RPA‐LFD assay takes 50 min less than the routine PCR method, is 100 times more sensitive and displays no cross‐reaction with other aquatic viruses. The combined isothermal RPA and lateral flow assay (RPA‐LFD) provides a simple, rapid, reliable method that could improve field diagnosis of CyHV‐2 when resources are limited.     

寡糖-中草药复合物和黄霉素对异育银鲫生长、免疫及抗病力的影响

在基础日粮中分别添加6 mg/kg黄霉素、0.1%寡糖-中草药复合物、0.2%寡糖-中草药复合物,连续投喂600尾异育银鲫(Carassius auratus gibelio)56 d后,测定鱼的生长、血清溶菌酶活性,丙二醛含量,超氧化物歧化酶活性,谷丙转氨酶活性,谷草转氨酶活性及血液生化指标等。结果显示:与对照组相比,添加6 mg/kg黄霉素显著提高了异育银鲫血液甘油三酯含量、血清溶菌酶活性;添加0.1%寡糖-中草药复合物显著提高了异育银鲫增重率、特定生长率、血清溶菌酶活性、超氧化物歧化酶活性;添加0.2%寡糖-中草药复合物显著提高了异育银鲫增重率、特定生长率、血液葡萄糖含量、血清溶菌酶活性、超氧化物歧化酶活性,显著降低了谷丙转氨酶活性、谷丙转氨酶/谷草转氨酶(即GPT/GOT)活性比值。鱼攻毒试验也表明试验各组都有死鱼,但是对照组死亡率是最高的。因此添加0.2%寡糖-中草药复合物能提高机体免疫机能与抗氧化能力,抵抗病原菌感染,保护肝脏,能促进鱼体生长。     

葡萄糖、维生素C对普安银鲫早期发育的影响

为探究葡萄糖和维生素C（VC）对普安银鲫（Carassius auratus gibelio）早期发育的影响,采用静水溶液浸泡法研究了葡萄糖和VC溶液浸泡中普安银鲫仔鱼出膜时间、孵化率、成活率及卵黄囊仔鱼生长特点。结果显示,葡萄糖溶液质量浓度低于15 g·L^-1,仔鱼出膜时间随着葡萄糖质量浓度的增加而缩短,孵化率、成活率、体质量和全长则升高;葡萄糖溶液质量浓度高于15 g·L^-1对普安银鲫的早期发育表现出抑制作用。VC溶液质量浓度低于30mg·L^-1时,仔鱼出膜时间随着ρ（VC）的增加而降低,孵化率、成活率、体质量和全长则升高。ρ（VC）高于30mg·L^-1对普安银鲫的早期发育表现出抑制作用。研究表明适宜浓度的葡萄糖和VC能促进普安银鲫的早期发育。     

红白鲫人工繁殖及鱼苗培育技术

采用鱼用LRH-A2催产剂,体腔注射法催情红白鲫亲鱼,使其同步产卵,经池塘孵化、鱼苗培育可以获得批量红白鲫鱼苗。     

银鲫肠道内抑制嗜水气单胞菌的潜在益生菌筛选及其特性研究

从养殖的银鲫(Carassius auratus gibelio)肠道中分离纯化得到60株具有不同特征的菌株,以嗜水气单胞菌(Aeromonas hydrophila)为指示菌,点种法初筛得到12株菌株,再通过牛津杯实验筛选出4株对嗜水气单胞菌有明显抑制作用(抑菌圈直径在14 mm以上)的益生菌疑似株,并进行了耐热试验、耐酸试验和人工肠液耐受试验,筛选出最符合益生菌功能特性的菌株YJ-9。该菌株在90℃高温水浴30 min后相对存活率为1.51%,在pH3的液体培养基中4 h内相对存活率为8.37%,活菌数都保持在106 CFU/mL以上,并且可以在人工模拟肠液中缓慢生长。在急性毒力实验中,10倍于实验剂量的菌株YJ-9对银鲫无毒,动物保护实验证明菌株YJ-9能有效增强银鲫对嗜水气单胞菌的免疫抵抗力,相对保护率达到80%。研究结果表明,菌株YJ-9可以作为一个新的饲用微生态制剂候选菌种。     

草金鱼幼鱼蛋白质需要量的初步研究

分别给初始体重为(19.56±1.78)g的金鱼幼鱼投喂蛋白质水平为26%、28%、30%、32%、36%、40%和42%的7种颗粒饲料,探讨草金鱼对饲料中蛋白质的需求。38d饲养试验结果表明:饲料中蛋白质含量36%时,草金鱼的增重率最大,显著高于蛋白质含量为26%、28%、30%和42%的饲料组(P<0.05),蛋白质含量为32%～40%的3个组间的增重率没有明显差异(P>0.05)。蛋白质含量为28%～44%饲料组的蛋白质效率无显著差异(P>0.05)。蛋白质含量为36%的饲料组饲料系数最低。通过对相对增重率和蛋白质效率两项指标的回归分析,确定草金鱼幼鱼配合饲料最适蛋白质含量为33.83%～35.31%。     

异育银鲫氨氮排泄与耗氧的研究

采用静态试验法对异育银鲫的氨氮排泄与耗氧进行了研究,结果表明：体重4．51—13．05g的异育银鲫,其单位体重排氨率为0．0269—0．0156mgN／（g·h）;溶氧的死亡临界值为0．56—0．25mg／L,窒息点为0．21—0．08mg／L。异育银鲫的呼吸属顺应型,瞬时耗氧速率与溶氧呈线性正相关,溶氧越低,瞬时耗氧速率越小;瞬时耗氧速率随体重的增加而减少;排氨率与体重呈良好的幂函数,其中单位个体排氨率随体重增大而增大,而单位体重排氨率却随体重增大而减小。