牛磺酸对急性氨中毒的鲫和草鱼抗氧化及炎症相关基因表达影响的比较

为了比较牛磺酸对急性氨中毒的鲫和草鱼缓释作用的差异,实验分别构建了4个处理组,组1实验鱼通过腹腔注射生理盐水,组2注射醋酸铵(鲫7 mmol/g,草鱼9 mmol/g),组3注射醋酸铵和牛磺酸(100μg/g),组4注射牛磺酸。毒性实验持续96 h。结果显示,组2鲫肝脏中SOD、CuZnSOD和CAT基因mRNA表达量显著低于组1和组3;组2和组3鲫肝脏中GPx基因mRNA表达量显著低于组1;组1鲫大脑中SOD、CuZnSOD、CAT和GPx基因mRNA表达量最高;组2草鱼肝脏中SOD、CuZnSOD、CAT和GPx基因mRNA表达量显著高于其他组;组2和组4草鱼大脑中SOD和CuZnSOD基因mRNA表达量显著低于组1和组3;组3草鱼大脑中CAT和GPx基因mRNA表达量最高;此外,组2鲫和草鱼肝脏及大脑中TNF和IL基因mRNA表达量均显著高于其他组。研究表明,鱼类氨中毒会扰乱机体的抗氧化酶系统和免疫应答,引起氧化损伤和炎症反应;草鱼通过提高抗氧化相关基因表达以应对氨中毒;牛磺酸能够有效缓解氨中毒对鲫和草鱼造成的氧化伤害,但牛磺酸并不能降低氨中毒对鲫和草鱼造成的炎症反应。     

Comparative functional responses of native and high‐impacting invasive fishes: impact predictions for native prey populations

Comparative functional responses (FRs) can predict impacts of invasive species, including piscivorous fishes, via quantifying their depletion of native food resources as a function of prey density. The utility of FRs for predicting impacts on prey populations by invasive fishes of different trophic guilds was tested here by comparing the FRs of the invaders Cyprinus carpio and Carassius auratus, with three native, trophically analogous fishes, Barbus barbus, Squalius cephalus and Tinca tinca. Chironomid larvae and Gammarus pulex were used as prey items. Predictions, developed from studies on the foraging of C. carpio and C. auratus in the literature, were that the invaders would have significantly higher consumption rates for chironomids than the native fishes, but not for G. pulex. Mean consumption rates for chironomids were significantly lower for both invaders than B. barbus and S. cephalus, but were similar to T. tinca. Barbus barbus had a significantly lower consumption rate of G. pulex than both invaders, but there were no significant differences between S. cephalus, T. tinca and the invaders. All FRs were type II, with FR curves for the invaders preying upon chironomids never being significantly higher than the native fishes, contrary to predictions. For G. pulex, some significant differences were apparent between the invaders and native fishes, but again were contrary to predictions. These results indicated that when predation impacts of invasive fishes could also be a function of their population density and body sizes, these parameters should be incorporated into FR models to improve impact predictions.     

Replacement of Fishmeal by a Mixture of Soybean Meal and Chlorella Meal in Practical Diets for Juvenile Crucian Carp,Carassius auratus

A growth trial was conducted to evaluate the effect of a mixture of soybean meal and Chlorella meal (SCM) as a dietary fishmeal (FM) substitute on growth performance, apparent digestibility coefficients (ADCs), digestive enzymatic activities, and histology of juvenile crucian carp, Carassius auratus. Five isonitrogenous and isoenergetic diets were formulated to replace 0 (SCM0), 25 (SCM25), 50 (SCM50), 75 (SCM75), and 100% (SCM100) of protein from FM with SCM, respectively. The diets were fed to triplicate groups of juvenile crucian carp for 6 wk. Weight gain, specific growth rate, feed intake, protein efficiency ratio, and intestinal digestive enzymatic activities (amylase, trypsin, and lipase) tended to decline with increasing FM replacement levels (P > 0.05). Dietary SCM substitution significantly influenced dry matter content in muscle, and crude protein and lipid contents in liver (P < 0.05). ADCs for dry matter, protein, lipid, energy, and most amino acids showed no significant differences between the control and SCM25 group, but tended to decline with replacement levels over 25%. Higher SCM substitution (50–100%) caused karyopyknosis and necrosis in liver, but intestinal histology did not show noticeable pathological changes. The present study indicated that FM could be replaced by 25% of SCM, without significant adverse growth performance, feed utilization, and histology of crucian carp.     

Natural bixin as a potential carotenoid for enhancing pigmentation and colour in goldfish (Carassius auratus)

Discovering natural carotenoids for colour enhancement and health benefits of fish is important to develop new feed formulations. We have purified natural bixin from achiote seeds and evaluated the effect of colour enhancing and pigmentation in goldfish. Varying levels of bixin‐based diets were prepared with 420 g kg^?1 of crude protein and 120 g kg^?1 of lipid content. Our results clearly showed that bixin (0.05, 0.10, 0.20 and 0.60 g kg^?1) based diets significantly (P < 0.05) enhanced the skin and fin colour at 30 and 60 days compared to diet without bixin. Interestingly, diet which contains 0.20 g kg^?1 bixin and commercial feed (with astaxanthin) had similar effect on carotenoid deposition in skin. Moreover, total carotenoid deposition in fin was higher than in skin of all bixin‐containing diets. However, 0.60 g kg^?1 bixin‐containing diet had lower specific growth rate (1.01 ± 0.01) and higher feed conversion ratio (2.05 ± 0.19) compared to the control group. The present results demonstrate that achiote bixin can be successfully used as an alternative natural carotenoid source against synthetic astaxanthin in fish feed. Our data indicate that 0.20 g kg^?1 is a suitable dietary level of bixin to ensure strong pigmentation, acceptable growth and feed utilization in goldfish.     

洞庭青鲫的形态和肌肉质构特性

从北民湖采集300尾洞庭青鲫,对其进行形态学性状、生长和肉质特性分析。结果显示:各年龄组形态指标的变异系数间的差异无统计学意义,表明其性状稳定;通过Von Bertalanffy生长公式拟合得出洞庭青鲫的渐近体长和体质量分别为308.41 mm和1 075.00 g,生长系数和理论生长起点年龄分别为0.369 5和–2.407 0龄,体质量生长拐点为0.17龄;体长体质量关系表明,洞庭青鲫在1～2龄生长迅速,且各年龄段洞庭青鲫体型均呈现等比增长趋势;通过鳞片鉴定的该群体中2龄群体为优势群体,占比66.67%;该群体的雌雄性别组成为10∶1;洞庭青鲫肌肉硬度和弹性分别为(2 822.95±556.97) g和1.317±0.01。综上可知,洞庭青鲫是1种具有优良性状且在低龄阶段生长迅速的鲫群体。     

羽毛粉部分替代鱼粉对异育银鲫生长及抗氧化能力的影响

【目的】探讨羽毛粉部分替代鱼粉外加角蛋白酶DP100(DP100)对异育银鲫生长及抗氧化能力的影响。【方法】配制7组饲料,Ⅰ组(对照组)以鱼粉为蛋白源(蛋白水平为317.9 g/kg),Ⅱ～Ⅶ组以羽毛粉蛋白替代10%的鱼粉蛋白,Ⅲ～Ⅶ组添加Ⅰ组相对短缺的4种必需氨基酸并分别添加0,100,200,300和400 mg/kg的DP100。用7组饲料分别饲喂异育银鲫83 d,试验结束后根据异育银鲫初始体质量、终末体质量(FBW)以及摄食量计算体质量增加率(BWG)、特定生长率(SGR)、饲料效率(FER)、蛋白质效率(PER),并解剖取肝胰脏和肠道,测定其消化酶(蛋白酶、脂肪酶、淀粉酶)活力及抗氧化指标(超氧化物岐化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)活力及丙二醛(MDA)含量)。【结果】Ⅱ和Ⅲ组异育银鲫FBW、BWG、SGR、FER、PER及肝胰脏和肠道蛋白酶、脂肪酶、淀粉酶、SOD、CAT、GSH-Px活力均显著低于Ⅰ组(P0.05),MDA含量显著高于Ⅰ组(P0.05);在添加DP100的各组中,Ⅳ组肠道SOD活力和肝胰脏CAT活力均与Ⅰ组无显著性差异,MDA含量显著高于Ⅰ组(P0.05),其余指标均显著低于Ⅰ组(P0.05),除Ⅶ组肠道蛋白酶活力显著低于Ⅰ组(P0.05)外,Ⅴ、Ⅵ和Ⅶ组各项指标均与Ⅰ组无显著性差异。【结论】羽毛粉替代10%鱼粉外加200～400 mg/kg DP100对异育银鲫生长性能、饲料利用和机体抗氧化能力无不良影响。     

怀山药皮对淇河鲫血清生化、免疫指标及组织结构的影响

为探究怀山药皮(Chinese yam peel,YP)对淇河鲫免疫的影响,选取平均体重为(106.76±3.74)g的淇河鲫240尾,随机分为对照组(NC)、0.5%怀山药皮添加组(LYP)、1%怀山药皮添加组(MYP)、2%怀山药皮添加组(HYP)4组,养殖8周,检测实验鱼生长指标、血清生化指标及免疫相关基因的表达情况。结果显示:添加怀山药皮对淇河鲫生长指标没有显著性影响;血液生化指标中谷草转氨酶活性在MYP组显著性降低,碱性磷酸酶的活性显著升高;与NC组相比,怀山药皮添加组肝脏细胞膜与核膜完整性增强,胞质破碎,核溶解、偏移现象减轻;与NC组相比,添加怀山药皮上调了抑炎因子(IL-10)、紧密连接蛋白基因(Claudin-1)、抗氧化基因(CAT和GST)和TLR通路基因(TLR4)mRNA表达量。以上结果表明,饲料中添加怀山药皮,能在一定程度上增强鱼体免疫力。     

基于主成分分析的吸鱼泵对鱼类损伤评价方法

采用主成分分析法建立吸鱼泵的损伤综合评价方法,为吸鱼泵的研究与改进提供装备技术参数。使用真空吸鱼泵对鲫鱼进行吸捕试验,获取鱼体损伤数据。通过测定体表损伤面积比率、24 h存活率、红细胞数量、白细胞数量、超氧化物歧化酶(SOD)活力、谷丙转氨酶(ALT)活力、肌酐(Cr)含量等多个关键指标值,采用主成分分析法进行相关性分析,建立损伤综合评价模型。结果显示：采用主成分分析法提取出3个主成分的累积贡献率达到78.232%,可反映出鱼体损伤的大部分情况;损伤评价综合评价模型：F=0.285X₁+0.111X₂+0.316X₃+0.366X₄-0.118X₅+0.234X₆,真空吸鱼泵对鱼的体表和内脏无显著损伤情况,综合得分-0.102,与对照组接近,表明真空吸鱼泵对鱼的损伤影响很小。研究表明,SOD活力、白细胞数和体表损伤面积比率是对损伤评价影响较大的数据指标,采用主成分分析法建立的综合损伤评价模型可以作为评价鱼损伤情况的一种可行方法,为吸鱼泵的改进研究提供了有力参考。     

异育银鲫“中科三号”对盐度和碳酸盐碱度的耐受性

研究了盐度和碳酸盐碱度对不同规格异育银鲫(Carassius auratus gibelio)"中科三号"鱼种的急性和慢性毒性。结果表明,异育银鲫"中科三号"大规格鱼种[L=(8.81±0.62)cm]48、72 h和96 h的盐度半致死浓度分别为15.433、14.352、13.855,盐度安全浓度为4.63;碳酸盐碱度在24、48、72、96 h的半致死浓度分别为73.105、71.861、71.198、70.368 mmol·L-1,碳酸盐碱度的安全浓度为20.33 mmol·L-1。小规格鱼种[L=(1.78±0.12)cm]24、48、72 h和96 h盐度的半致死浓度分别为11.339、11.026、10.653、10.080,盐度安全浓度为2.98;碳酸盐碱度的半致死浓度分别为52.656、51.889、50.378、49.664 mmol·L-1,碳酸盐碱度的安全浓度为13.20 mmol·L-1。大规格"中科三号"鱼种对盐度和碳酸盐碱度的耐受性均比小规格鱼种强;慢性毒性实验中异育银鲫"中科三号"鱼种[L=(3.73±0.12)cm]的特定生长率和相对增重率均随着盐碱浓度的增大而降低。60 d实验后盐度3、5和7组的特定生长率分别为1.14、0.67和0.23,相对增重率分别为98.64、49.24和14.80;碳酸盐碱度7、12和17 mmol·L-1组的特定生长率分别为1.12、0.66和0.29,相对增重率分别为96.06、48.40和19.23。盐度和碳酸盐碱度浓度越强,对异育银鲫"中科三号"鱼种生长的影响越大。     

Genetic identification of a newly synthetic allopolyploid strain with 206 chromosomes in polyploid gibel carp

A newly synthetic allopolyploid strain (SAS) was selected and established from gynogenetic offspring of gibel carp clone A⁺ with 156 chromosomes induced by common carp sperm with 50 chromosomes. In this study, the allopolyploid strain was detected to contain 206 chromosomes, and the growth trait was evaluated to have 25.15% growth faster than that of clone A⁺. Genetic marker analyses of transferrin (Tf) alleles, ITS1 sequences and mtDNA D‐loop sequences indicated that the allopolyploid strain was synthetized from maternal gibel carp clone A⁺ and paternal common carp, and the synthetic chromosome sets were further confirmed by genomic in situ hybridization (GISH) and chromosome localization of 45S rDNA. Significantly, the synthetic allopolyploid strain has tended to be stable by five successive generations of gynogenesis, because it still keeps unisexual reproduction mode of gynogenesis. Therefore, it will become a novel variety for gibel carp aquaculture in future.