玉米蛋白粉替代鱼粉对异育银鲫生长和甲状腺激素水平的影响

分别用0%(对照组)、4%、8%和12%玉米蛋白粉替代饲料中0%、33.33%、66.67%和100%的鱼粉配制4种等氮、等能的试验饲料,在室内循环养殖系统中饲养初始体质量为(13.68±1.77)g异育银鲫60d,研究玉米蛋白粉替代鱼粉对异育银鲫生长的影响,同时以15d为采样间隔研究鱼体血清中三碘甲腺原氨酸(T3)和甲状腺素(T4)含量的变化。结果表明:对照组与8%替代组的饲料系数无显著差异,且均显著低于4%和12%替代组;玉米蛋白粉对异育银鲫生长无显著影响;饲养30到60d对血清中T3含量无显著影响,而15d对照组血清中T3含量显著高于其余各替代组;30d时4%和8%替代组血清中T4含量与对照组无显著差异,而12%替代组显著低于对照组,而60d时与对照组无显著差异;60d时,各组鱼体的生长与T3、T4含量变化趋势相同。在本实验条件下,玉米蛋白粉在异育银鲫饲料中的适宜用量为4%～8%,对鱼粉的适宜替代量为33.33%～66.67%。     

日本白鲫BMP15和GDF9基因片段的克隆及组织表达分析

根据斑马鱼GDF9、BMP15基因的保守序列设计引物,采用RT PCR方法扩增获得日本白鲫GDF9、BMP15基因片段。日本白鲫GDF9基因片段长778 bp,编码145个氨基酸;BMP15基因片段长811 bp,编码270个氨基酸。氨基酸序列分析表明日本白鲫GDF9与斑马鱼的同源性最高,为78%,与其他物种的同源性在58%~78%之间;日本白鲫BMP15与斑马鱼同源性最高,为80%,与其他物种的同源性在30%~80%之间。系统进化树分析显示,鱼类的GDF9基因独立聚成一支,其中日本白鲫的GDF9基因与斑马鱼的GDF9基因聚成一支;鱼类的BMP15基因独立聚成一支,其中日本白鲫的BMP15基因与斑马鱼的BMP15基因聚成一支。半定量PCR结果显示,BMP15 mRNA在脾脏、肝脏、鳃、脑、心脏、肌肉、肾脏、卵巢中均有表达,其中卵巢中表达量最高;GDF9 mRNA在肝脏、脑、心脏、肌肉、卵巢中均有表达,而在脾脏、鳃、肾脏中表达量极低或不表达,在卵巢中表达量最高,为进一步研究日本白鲫GDF9与BMP15基因的结构与功能奠定了基础。     

4种添加剂对异育银鲫生长、消化酶活性及抗氧化能力的影响

以基础饲料为对照,分别在基础饲料中添加1%绿康源(试验Ⅰ组)、1%绿康源+0.1%合生素(试验Ⅱ组)、0.1%合生素(试验Ⅲ组)、2%小肽(试验Ⅳ组),连续投喂300尾初始体重31 g的异育银鲫(Carassius auratusgibelio)60 d后,测定试验鱼生长,肠消化酶活性及血清、肝胰脏超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性。结果表明:(1)试验Ⅲ、Ⅳ组增重率(WGR)显著高于对照组(P<0.05),饲料系数(FCR)显著低于对照组(P<0.05);试验Ⅰ、Ⅱ组与对照组差异不显著(P>0.05)。(2)试验Ⅲ、Ⅳ组的肠蛋白酶、淀粉酶活性显著高于对照组(P<0.05),脂肪酶活性与对照组差异不显著(P>0.05);试验Ⅰ、Ⅱ组中仅后者肠蛋白酶活性显著高于对照组(P<0.05)。(3)除试验Ⅱ组血清SOD活性显著高于对照组外(P<0.05),不同添加剂对血清SOD、CAT活性无显著影响(P>0.05);试验Ⅰ、Ⅱ、Ⅲ组肝胰脏SOD、CAT活性显著高于对照组(P<0.05),试验Ⅳ组与对照组差异不显著(P>0.05)。结果说明,试验Ⅲ组显示明显的促生长和抗氧化效果,试验Ⅰ、Ⅱ组对提高试验鱼的抗氧化作用明显,试验Ⅳ组则生长最佳。     

Fluctuating asymmetry, abnormalities and parasitism as indicators of environmental stress in cultured stocks of goldfish and carp

Knowledge about the effects of captivity and environmental stress on fish populations is basic to culture them for ornamental, conservation or exploitation purposes. The aim of this study was to test how captivity affect morphological development of bilateral characters and whether levels of fluctuating asymmetry, morphological abnormalities and ectoparasites reflect developmental stress caused by adverse environmental conditions in two species of cyprinids, goldfish Carassius auratus and two varieties of carp Cyprinus carpio, scale and mirror carp. Samples from captivity were caught in an artificial pond (Madrid City, Spain), which presents poor environmental conditions; while samples from nature were captured in the Ebro River basin (NE Spain). Six meristic and four morphometric bilateral characters were measured and compared between the two samples. Additionally, the incidence of morphological abnormalities and ectoparasites was also recorded. Captive goldfish presented significant lower number of scales of the lateral line, scale rows above lateral line and length of pectoral and ventral fins. Captive carps showed significant shorter first barbels and longer ventral fins. Ornamental goldfish showed significant higher levels of fluctuating asymmetry than wild samples for number of branched rays of pectoral fin, lateral line, scale rows below lateral line and length of pectoral and ventral fins. Ornamental carps presented a similar trend for the same characters, except for branched rays and length of pectoral fins, together with the length of second barbels. In the artificial pond, the incidence of abnormalities was higher in carp, whereas goldfish showed a higher occurrence of ectoparasites. These facts support the hypothesis of a different species response to environmental stress. The overall results indicate that fish from the artificial pond are subjected to environmental stress caused by adverse conditions such as overcrowding and lower water quality. Moreover, estimated parameters in this study mean a useful tool to detect developmental instability in confined fish.     

分级对银鲫生长和个体大小差异的影响

在室内水槽进行12周的饲养实验以检验分级对银鲫生长和鱼群内个体大小差异的影响。用隔网将实验水槽分为两部分，每个水槽内放养10尾大鱼（体重8.0~9.0 g）和10尾小鱼（体重6.5~7.5 g），分级时将个体大小相近的10尾鱼分布在隔网同一侧。实验中，3组鱼分别隔1周、2周或4周分级1次，1组鱼不进行分级作为对照。鱼摄食率和生长率随分级间隔时间缩短而降低。实验结束时，隔1周分级1次的鱼体重低于对照组，隔4周分级1次的鱼体重与对照组无显著差异。实验结束时被分级的鱼群中大鱼体重的变异系数高于小鱼，表明大鱼对分级操作更敏感。本实验结果表明,分级未能明显提高银鲫生长速度和降低鱼群内个体大小的差异程度。     

几种植物源提制品对鱼的毒性与安全性评价

为全面评价几种植物源提制品的安全性,采用半静态法测定了其对红鲫鱼的急性毒性。78%川楝素、2.5%楝树粗提粉、0.5%川楝素乳油对红鲫鱼的LC50(96 h)分别为1 417、30.59和37.52 mg/L;95%鬼臼毒素、1.5%砂地柏乙醇浸膏、0.75%鬼臼毒素乳油对红鲫鱼的LC 50(96 h)分别为161.6、4.49和8.15 mg/L。根据LC50(96 h)值的大小划分等级,川楝素、鬼臼毒素和0.5%川楝素乳油对鱼类属于低毒;0.75%鬼臼毒素乳油属于中毒。就鱼类安全性而言,0.5%川楝素乳油的安全使用浓度为3.75 mg/L,0.75%鬼臼毒素乳油的安全使用浓度为0.82 mg/L。     

氟虫腈等7种杀虫剂对鲫鱼的毒性及安全性试验研究

本文研究了氟虫腈等杀虫剂对鲫鱼的急性毒性作用。室内毒力测定结果表明:溴氰菊酯、高效氯氟氰菊酯对鲫鱼的毒性最高,毒死蜱、三唑磷毒性较高,氟虫腈、阿维菌素较安全,杀虫双对鲫鱼最安全。大田实验结果与室内实验结果基本一致,只是溴氰菊酯在稻田环境下,对鲫鱼的急性毒性大幅度下降。     

新疆银鲫肝胰脏和肠道蛋白酶活性的初步研究

本文分析了研究了银鲫肝胰脏和肠道蛋白酶活性及其在肠内的分布状况,发现银鲫肝胰脏和肠蛋白酶最适ｐＨ范围在ｐＨ７．６－９．５之间,其肠道蛋白酶活性略高于肝胰脏蛋白酶活性。肠道蛋白酶以中肠活性最高。     

金黄地鼠（Mesocricetus auratus）朊蛋白基因的克隆及其原核表达

采用RT-PCR技术从金黄地鼠(Mesocricetus auratus)脑组织获得朊蛋白基因(Prion protein nucleic acid,PRNP)开放阅读框(Open reading frame,ORF),截去其N端信号肽(66 bp)和C端GPI锚定位点(69 bp)形成朊蛋白编码区PRNPx;将编码区重组于融合表达质粒Pet-DsbA中,并在大肠杆菌BL21(DE3)plysS中经IPTG诱导表达,并经Western-blot验证。结果表明,金黄地鼠PRNP基因ORF区全长为765 bp,编码254个氨基酸的前体蛋白,核苷酸序列与已发表金黄地鼠序列(M14054)同源性为99.87%,其第116个氨基酸发生了同义突变由GCT变为GCC;朊蛋白在大肠杆菌得到高效表达,产物是相对分子质量为47 000的融合蛋白。     

Seasonal morphological and biochemical changes of Dahlgren cells implies a potential role of the caudal neurosecretory system (CNSS) in the reproduction cycle of teleostean fish

The purpose of this mini-review is to summarize recent research on the seasonal morphological and biochemical changes of Dahlgren cells in the caudal neurosecretory system (CNSS) of the freshwater teleosts carp Carassius auratus. The quantitative proof for these seasonal changes in the morphology and biochemistry of Dahlgren cells reflects the relationship between the CNSS and the reproduction cycle of fish and implies that the CNSS is probably involved in the reproduction process of fish.