放养密度和微生态制剂对施氏鲟养殖水质的影响

将初始体质量(54.86±10.19)g的施氏鲟Acipenser schrenckii饲养在面积16m~2(4m×4m)、水深1.7~1.9m的陆基围隔中,密度分别为2 000尾/667m~2、3 000尾/667m~2、4 000尾/667m~2和5 000尾/667m~2,每个密度组均设3个平行,常规饲养,混合泼洒光合细菌、枯草芽孢杆菌和乳酸菌,第一次泼洒量为光合细菌50m L、枯草芽孢杆菌50g和乳酸菌50g,之后每5d泼洒第一次量的1/2,研究微生态制剂对静水土养殖池塘水质的影响。结果显示:水体中溶解氧量随养殖密度的增加逐渐降低(P0.05),氨氮、亚硝酸盐浓度随养殖密度的增加逐渐升高(P0.05)。在使用微孔增氧的条件下,泼洒微生态制剂对溶解氧量和氨氮浓度的影响不显著(P0.05),但显著降低了水体亚硝酸盐浓度(P0.05),显著增加了浮游动物生物量(P0.05)。     

Genotyping,pedigree reconstruction and endocrinological characterization of Acipenser naccarii (Bonaparte, 1836) using microsatellite markers and plasma steroid levels

This study aimed to set up a method for the long‐term management of Adriatic sturgeon, through the analysis of sex steroids and the genetic profiling of individuals in order to maximize the already reduced genetic variability of this species. Ten A. naccarii adults (nine of captive origin, one captured in the Ticino river and then moved into captivity) and eight subadults located in a semi‐natural land‐locked pond in Abbiategrasso (Milan, Italy) were analysed. Plasma testosterone differed significantly in the eight analysed subadults allowing their differentiation into two groups: the first group with an average testosterone concentration of 5.42 ± 1.31 ng/ml (probably female) and the second group with an average of 423.14 ± 75.97 ng/ml (probably male), as subsequently confirmed by artificial stripping. The plasma testosterone level was also significantly different between adult males and females (371.37 ± 43.58 vs. 95.34 ± 51.10 ng/ml), while the E2 levels showed no significant differences. Animals were genotyped on the basis of 10 microsatellite loci and their parental relationships were defined: four adults, two females and two males, generated the eight subadults. On the basis of pedigree analyses and genetic distances, 15 unrelated couples were identified for the future breeding seasons. Finally, the adult female captured in the Ticino River showed an interesting genetic profile, widely different from all of the other 17 specimens analysed, and represents a valuable source of genetic diversity.     

不同配比南极磷虾粉饲料对网箱养殖俄罗斯鲟生长及氟累积的影响

配制南极磷虾粉替代饲料中鱼粉比例分别为0%、10%、20%、30%的4组饲料饲喂俄罗斯鲟(Acipenser gueldenstaedtii)200 d后,分析南极磷虾粉替代部分鱼粉对网箱养殖俄罗斯鲟生长和鱼体组织氟残留的影响。结果表明:(1)随着南极磷虾粉替代比例的升高,俄罗斯鲟的末重、增重、特定生长率、蛋白质效率先上升后下降,饲料系数先降低后升高,10%组显著高于对照组和其它试验组(P0.05);(2)实验结束时,俄罗斯鲟肌肉、肝脏和鱼鳔的氟浓度低于检测限,但鳃、皮、脊骨和背骨呈现剂量浓度效应,各试验组较对照组显著升高(P0.05)。综上所述,在本实验条件下,在俄罗斯鲟饲料中加入10%比例的南极磷虾粉时获得最佳生长效果和较低的组织氟累积。     

中华鲟神经内分泌多肽7B2基因克隆及组织特异性表达

以中华鲟(Acipenser sinensis)脑垂体总RNA为模板,采用RT-PCR和RACE方法,获得中华鲟神经内分泌多肽(7B2)基因的3个重叠片段,测序后拼接得到986 bp全长基因序列,其中包括5'端非翻译区(5′-UTR)14 bp、3′端非翻译区(3-′UTR)261 bp和开放阅读框711 bp。翻译编码236个氨基酸。其中前43个氨基酸为7B2的信号肽。经BLAST比对发现中华鲟7B2蛋白的同源性与斑马鱼(Danio rerio)的相似性最高为82%。系统发育分析表明,中华鲟与斑马鱼亲缘关系最近。半定量RT-PCR分析表明:在脑中7B2 mRNA表达量最高,心脏、性腺、胰等组织中表达次之,肠、肾、皮肤等组织中少量表达,肝和鳃几乎不表达。     

MS-222不同处理方式对史氏鲟和中华鲟麻醉效果的影响

MS-222的药液浸浴和药液鳃部喷洒可作为史氏鲟（Acipenser schrenckii）和中华鲟（Acipenser sinensis）的麻醉方式。在水温16～18℃的条件下,史氏鲟的浸浴有效浓度为90～110 mg/L,浸浴安全时间不超过30 min;中华鲟的浸浴有效浓度为80～100 mg/L,浸浴安全时间不超...     

Low levels of Aflatoxin B1 could cause mortalities in juvenile hybrid sturgeon,Acipenser ruthenus ♂×A. baeri♀

Toxicity of aflatoxin B₁ (AFB₁) was investigated in juvenile hybrid sturgeon Acipenser ruthenus ♂ × A. baeri♀, an important coldwater finfish farmed in China and other countries. Seven experimental diets (Diet A–G) containing different levels of AFB₁ (0, 1, 5, 10, 20, 40 and 80 μg kg^?1 diet) were fed to juvenile sturgeon weighing 10.53 ± 0.17 g kg^?1 to determine its effect on survival, growth, feed consumption, hematocrit, liver histology as well as muscular and hepatic toxin accumulation. The experiment lasted for 35 days and was conducted in two periods of 25 and 10 days each. No external changes or unusual behaviour was observed in the fish fed diets with AFB₁. Mortality was observed in fish fed with highest levels of AFB₁ (80 μg kg^?1– Diet G) from day 12 onwards. After 25 days, fish fed the diet of 80 μg AFB₁ kg^?1 showed significant lower survival (50 ± 5.77%) followed by those fed 40 μg AFB₁ kg^?1 diet (80 ± 5.77%) and 20 μg AFB₁ kg^?1 diet (86.66 ± 3.33%). No significant difference was observed in specific growth rate (SGR) or hepatosomatic index (HSI) between groups. Hematocrit was significantly higher in the fish fed the diet of highest AFB₁. The fish were weighed at day 25 in some treatments (Diets F and G) because of high mortality. However, feeding was continued for another 10 days to observe mortality or behavioural changes if any in the other groups. After 35 days, survival in the fish fed Diet F (40 μg AFB₁ kg^?1) was 40% and those fed Diet E (20 μg AFB₁ kg^?1) was 36.2%. Significant histopathological changes including nuclear hypertrophy, hyperchromasia, extensive biliary hyperplasia, focal hepatocyte necrosis and presence of inflammatory cells were observed in the liver of fish fed high levels of aflatoxin (40 and 80 μg kg^?1). AFB₁ accumulation in fish muscle and liver increased with increased dietary AFB₁ levels. It could be confirmed that 10 μg AFB₁ kg^?1 diet was the maximum allowable level in hybrid sturgeon diet.     

史氏鲟南移培育的技术研究与探讨

本文介绍史氏鲟从黑龙江南移至莆田市养鳗池的培育技术研究结果。培育过程仔鲟成活率达74．5％，人工配合饲料驯化转口率达88．7％，从二日龄苗种培育成平均体重690g。并对史氏鲟南移培育生长的基本要素进行了探讨。     

维生素B6对史氏鲟幼鱼胰蛋白酶活性的影响

试验研究了饲料中不同水平维生素B6对史氏鲟（Acipenser schrencki）幼鱼胰蛋白酶活性的影响。在温度为（20±0.5）℃、pH值为6.8～7.5的条件下,研究了低蛋白含量（28%）饲料中,添加不同水平的维生素B6（0、15、30、45、60、75mg/kg）对史氏鲟幼鱼[（34.07±3.44）g]胰蛋白酶活性的影响。结果表明,饲料中的维生素B6添加量为45～60mg/kg时,对幼鲟胰蛋白酶的激活作用最大,并可相应提高对饲料蛋白质的消化率。     

Growth,survival rate and fatty acid composition of sterlet (Acipenser ruthenus) larvae fed fatty acid‐enriched Artemia nauplii

We evaluated the growth and survival rate of sterlet (Acipenser ruthenus) larvae fed Artemia nauplii enriched with Olioω3 or Red Pepper commercial emulsions (BernAqua NV, Belgium). Sterlet larvae, 0.022 ± 0.002 g body weight, were randomly assigned to one of three feeding regimes with two different feeding durations. After administering live feed for 7 or 14 days, larvae were weaned onto commercial food and reared to 36 days posthatching (28 days of feeding). There were no significant differences in body weight among groups at the end of the trial. A significantly higher survival rate (p < 0.05) was observed in larvae fed Artemia enriched with Red Pepper for 14 days compared to other feeding regimes. Based on the analysis of growth parameters, we can conclude that 7 days of live feeding to be sufficient for efficient rearing of sterlet larvae. And longer duration of live feeding with use of special enrichment can be recommended for a higher survival rate.     

电麻醉对西伯利亚鲟幼鱼血液生化指标的影响

设置5个麻醉组(15～35 V)与1个对照组(0 V),研究直流电麻醉对西伯利亚鲟幼鱼血液13项生化指标的影响.随着电压强度升高,西伯利亚鲟麻醉组总蛋白与白蛋白质量浓度逐渐升高,35 V组总蛋白质量浓度显著高于15 V组与20 V组.高密度脂蛋白、低密度脂蛋白和甘油三酯浓度在15 V组中最低,在35 V组最高,35 V...