孟家段水库鲢、鳙的生长及提高鱼产量措施

孟家段水库渔获鲢鳙中，鲢年龄组成不合理，5～7龄鱼占其总尾数67%。鲢、鳙生长较慢。应加大放养规格至13～14cm，降低放养量至每年2.5万kg，鲢鳙比例调整为3:7，加大对凶猛的捕捞力度。     

Growth, Yield, Dressout, and Net Returns of Bighead Carp Hypophthalmichthys nobilis Stocked at Three Densities in Fertilized Earthen Ponds

Abstract.— Bighead carp Hypophthalmichthys nobilis have been raised in the United States for two decades and sold through the livehaul market, but their profitability in monoculture has not been evaluated. Three studies were conducted in 0.10-ha earthen ponds to evaluate the effect of bighead carp stocking density on growth, yield, dressout yield. and net returns. Initially, bighead carp (average weight of 0.36 kg) were stocked at rates of 500, 320, or 130 fish/ha with three replicates of each treatment. Stocking rates for 2-yr-old fish (average weight of 2.45 kg) were reduced to 320, 220, or 130 fish/ha in the second year. Net yields of bighead carp stocked at 500 fish/ha (963 kg/ha) were significantly higher ( P < 0.05) than net yields at the 320 fishha density (771 kg/ha), and these were significantly greater ( P < 0.05) than net yields at 130 fish/ha (369 kg/ha) in the first growing season. Net yields in the second growing season were not significantly different ( P > 0.05) among densities. There were no significant differences ( P > 0.05) among treatments in yearly growth which ranged from 11–17 g/d in the first and from 6–13 g/d in the second growing season. Dressout percentages for whole-dressed, steak, shank fillet, and shank fillets with white meat only did not differ with stocking density ( P > 0.05). Enterprise and partial budget analysis indicated that monoculture of bighead carp in fertilized ponds is profitable only in the short run at average livehaul market prices, because revenues exceeded variable but not fixed costs. The negative net returns, when all costs were accounted for, indicated that it is not profitable to construct ponds solely for monoculture of bighead carp.     

密云水库鲢鱼、鳙鱼营养成分分析与评价

为全面了解密云水库鲢鱼、鳙鱼的营养特征,以密云水库秋季鲢鱼和鳙鱼为研究对象,对其肌肉的水分、蛋白质、粗脂肪、灰分、矿物质元素含量以及氨基酸、脂肪酸组成进行分析。研究结果表明,密云水库鲢鱼和鳙鱼肌肉蛋白质含量分别为(18.40±0.40)%和(18.60±0.57)%,粗脂肪含量为(0.60±0.10)%和(1.48±0.91)%,富含人体所需的钾、钠、钙、镁、磷等常量元素及铁、锰、锌、硒等微量元素;鲢鱼、鳙鱼肌肉中,18种常见氨基酸均被检出,其中谷氨酸含量高,必需氨基酸分别占氨基酸总量的40.00%和40.16%,必需氨基酸指数分别为99.15和98.76;鲢鱼、鳙鱼肌肉中分别检出脂肪酸12种和19种,相对含量均表现为多不饱和脂肪酸>饱和脂肪酸>单不饱和脂肪酸,而多不饱和脂肪酸中均以二十二碳六烯酸相对含量最高,其次为二十碳五烯酸,两者之和分别达30.64%和23.79%。研究结果表明,密云水库鲢鱼、鳙鱼是良好的蛋白质来源,氨基酸组成合理,富含矿物质和有益脂肪酸,具有很好的营养价值和可食用性。     

Growth, Yield, Dressout, and Net Returns of Bighead Carp Hypophthalmichthys nobilis Stocked at Three Densities in Catfish Ictalurus punctatus Ponds

Abstract— Alternative fish species that can be cultured together with catfish Ictalurus punctatus provide an opportunity to diversify caffish farms. A 2-yr study was conducted in 0.10-ha earthen ponds to evaluate the effect of bighead carp (BHC) stocking density on growth, yield, dressout yield, and net returns. Initially, bighead carp (average weight of 22 g) were stocked at rates of 380, 750, or 1,130 fishha in ponds with catfish. Caffish were cultured under commercial conditions by stocking caffish at a density of 12,500/ha, aerating nightly and feeding at an average rate of 82 kgha per d. Stocking rates for 2-yr-old fish were reduced to 77, 260, and 435/ha in the second growing season. There were no significant differences among treatments ( P > 0.05) in summer growth of bighead carp in either year. Bighead carp stocked at 1,130 fishha had significantly higher yields than those stocked at 380/ha, but did not reach minimum market size of 2.2 kg during the first year ( P > 0.05). There were no significant differences ( P > 0.05) in caffish growth, yield, survival, or feed conversion ratios due to the bighead carp stocking densities. Partial budget analysis indicated that net benefits were positive for all three treatments over a range of prevailing prices of bighead carp. Bighead carp production in catfish ponds is economically feasible over a wide range of prices. Given the market risk of producing smaller fish at the higher density, the medium density is the preferred stocking density of fingerling bighead carp in catfish ponds.     

鳙鳃凝集素的分离纯化及理化性质的研究

利用DEAE-Sepharose FF离子交换和Sephacryl S-200 HR及Superdex 200 10/300 GL分子筛层析技术,从鳙鳃组织中分离纯化到一种岩藻糖专一的凝集素,命名为GANL.在还原SDS-PAGE电泳上显示单一蛋白染色带,其亚基相对分子质量为37 kD.经Superdex 200凝胶过滤层析测得其天然相对分子质量为220 kD.GANL的中性糖含量为13.4%.因此,GANL作为一种由相同亚基组成多亚基糖蛋白.GANL对兔红细胞有专一的凝集活性,其凝集活性不依赖Ca~(2+).在被测的单糖、双糖及糖蛋白中,仅岩藻糖能抑制其凝集活性.氨基酸分析表明GANL的Asp、Glu、Leu、Val、Lys的含量较高,Cys-S的含量为0.81%.GANL的最适pH为8～9;具有很高的热稳定性,最适温度为50 ℃.     

二、三倍体细鳞鲑幼鱼生长特性的研究

细鳞鲑Brachymystax lenok成熟卵受精后20min,在26℃下处理20min,获三倍体细鳞鲑幼鱼。将二、三倍体细鳞鲑幼鱼饲养在210cm×50cm×45cm(水深60cm)的玻璃钢水槽内,每槽30尾,每种倍性鱼类设3个平行,水温8~10℃下常规养殖90d后,测定试验鱼体长、体质量和肥满度等生长指标。结果表明,三倍体细鳞鲑幼鱼的日增重、增重率和特定生长率显著高于二倍体幼鱼(P<0.05),但二、三倍体细鳞鲑幼鱼的肥满度、饲料系数和存活率等差异不显著(P>0.05)。二、三倍体细鳞鲑幼鱼的体长(L)与体质量(W)呈幂指数增长相关,均为异速生长。两者的特定生长率随体质量的变化趋势相同,均呈显著负相关。本研究结果表明:三倍体细鳞鲑幼鱼的生长特性优于二倍体,可示范养殖、推广。     

鲤、鲢、鳙、草鱼消化道消化酶种类和活性的比较研究

采用聚丙烯酰胺凝胶电泳方法研究了鲤、鲢、鳙、草鱼亲鱼消化道消化酶的种类;用比色法及滴定法分别测其消化酶相对活性。结果表明：鲤、鲢、鳙、草鱼4种鱼消化道的蛋白酶、淀粉酶活性与食性有明显的相关性。其中,蛋白酶活性依次为鲤〉鲢〉鳙〉草鱼;淀粉酶活性依次为草鱼〉鲤〉鳙〉鲢。脂肪酶活性与食性的关系不明显。四种鱼消化酶的表达与消化道的组织结构特征相一致,消化道前2／5部位（G1、G2）的消化酶活性最高,是无胃鱼消化道的主要消化场所。消化道中央部位（G3）的消化酶活性次之,能将未消化完全的食糜进一步消化,而消化道后段（G4、G5）消化酶活性最低。可见,消化酶活性及消化功能呈递减形式,食物在消化道中随着消化、吸收,逐渐排出体外。本研究为鲤、鲢、草鱼、鳙4种鱼的营养生理学、高效饲料配比的研制及种质资源的科学管理提供理论依据。     

鲤、鲢、鳙、草鱼消化道消化酶种类和活性的比较研究

采用聚丙烯酰胺凝胶电泳方法研究了鲤、鲢、鳙、草鱼亲鱼消化道消化酶的种类;用比色法及滴定法分别测其消化酶相对活性。结果表明：鲤、鲢、鳙、草鱼4种鱼消化道的蛋白酶、淀粉酶活性与食性有明显的相关性。其中,蛋白酶活性依次为鲤〉鲢〉鳙〉草鱼;淀粉酶活性依次为草鱼〉鲤〉鳙〉鲢。脂肪酶活性与食性的关系不明显。四种鱼消化酶的表达与消化...     

滆湖鲢和鳙肠道生长格局研究

肠道形态种间差异是动物对食物质量的长期进化响应,本文研究了滆湖鲢(Hypophthalmichthys molitrix)鳙(Aristichthysnobilis)肠长(GL)和肠重(GM)两种肠道形态参数的生长格局,并探讨了它们对鲢鳙食性差异的指示作用。结果表明,滆湖鲢、鳙GL相对身体大小(体长BL和体重BM)、GM相对GL、肠道内含物重(GCM)相对BM均呈正异速生长或增加,鲢鳙GM相对BM分别呈等速和负异速生长。相对肠长(RGL)、ZI指数、相对肠道内含物重指数(RGCM)鲢显著大于鳙,GM/GL比值正好相反,相对肠重(RGM)鲢鳙间无显著差异。根据文献对比及RGL与营养级的经验公式,鲢鳙均为偏浮游植物杂食性鱼类,这与鳙为偏浮游动物食性鱼类的普遍认识不太一致,说明国内需要更多的研究以增加RGL对鱼类食性的指示作用。与鳙相比,鲢从更多且质量较低的食物中满足营养和能量需求的主要机制是增加肠道长度而不是分配更多组织给肠道。肠长能而肠重不能识别体型相似的2个近缘物种(鲢鳙)的食性差异。     

微粒饲料对鳙鱼繁育的影响

微粒饲料是模拟鳙鱼所滤食浮游生物的大小及营养成分配制，用鱼粉、豆粕、玉米、小麦并添加多种维生素及微量元素。1998年对96尾长江水系鳙鱼生产性应用来看．效果较显著．产卵量和产苗量比对照组明显提高。     

增温水体对鲢、鳙的生长、血液及生理指标的影响

陡河水库纳入电厂热排水后,年均水温升高3℃左右。根据水温及等温线分布情况,将库区划分为增温区、弱增温区、自然水温区三个区域。通过一年的定点网箱监测,结果表明:自然水温区鱼类生长最好,其次为增温区,弱增温区最差。增温不仅改变了鱼类生长,而且鱼类血液及生理指标也发生了改变。     

南四湖鲢、鳙增殖放流后生长的跟踪监测

2012年6月-11月,对2012年4月在南四湖增殖放流的鲢、鳙生长状况进行了连续5次跟踪调查。结果表明：鲢体质量变化在50-400g范围内,为1-2龄;鳙体质量集中在50-350g,为1-2龄;增殖鲢生长（L,体长;W,体质量）与捕捞时间的关系方程为：L=12.633＋2.3391M＋0.0648M2,W=-89654＋61.933M＋2.3341M^2;鳙L=13.186＋1.004M＋0.2449M2,W=99.204-33.203M＋12.141M2。捕获南四湖鲢、鳙个体远未达到渐进体质量乃至拐点体质量,尚处于快速生长期,在增殖放流与捕获中应加强科学规范与管理。     

Survival and Growth of Bighead Carp Fry Exposed to Low Salinities

Bighead carp (Aristichthys nobilis Oshima) fry of various ages (11, 18, and 35 days post-hatch) were exposed to the low salinities encountered during the annual intrusion of seawater in Laguna Lake, Philippines. Practical indices of salinity tolerance assessed the effect of a 96 h direct exposure to low salinities (0–16). Mean (MST) and median survival times (MST50) of fry decreased as salinity of rearing medium increased. Younger fry were less able to tolerate exposure to these salinities than their older cohorts. Median lethal salinity after 96 h (MLS) revealed higher tolerance among 35–day old fry (7.6) than 11 (2.3) and 18–day old fry (6.0), demonstrating that survival in saline water depends on their age at initial exposure to low salinities. Mean body weight of 18–day old fry reared in 0 and 2 for 3 and 4 weeks was higher than for those reared in 4 and 6 for the same period. Growth over these periods was inversely related with the range of salinities tested. These results demonstrate that, despite their known stenohalinity, bighead carp fry possess some degree of osmoregulatory capability, allowing them to survive and grow in lakes subjected periodically to saltwater inflow.     

Limnological Factors Influencing Growth of Cage-Cultured Bighead Carp ♀ x Silver Carp ♂ Hybrids

Four 2-m³ cages each stocked with 120 bighead carp ♀ X silver carp ♂ hybrids were placed in each of four ponds varying in trophic status from mesotrophic to hypereutrophic. Fish were cultured, without feeding, from 13 March to 1 October, 1987. All fish survived but lost weight (-0.37 g/fish/day) in the mesotrophic pond. Maximum fish growth rate occured in the two eutrophic ponds (6.61 and 7.04 g/fish/day). Fish growth in the hypereutrophic pond was about one-half (3.64 g/fish/day) that in the two eutrophic ponds until a sudden thermal destratification and dissolved oxygen depletion killed all the fish. Multiple linear regression analysis revealed that gross phytoplankton primary productivity accounted for 68% of the variation in fish weight gain (R² = 0.68; P < 0.0001) in all ponds. When eliminating primary productivity data from the statistical model, number of algal taxa comprising phytoplankton communities explained 49% of the variation in fish growth (R² = 0.49; P < 0.0001). Conditions of hypereutrophy believed to be detrimental to fish growth were: a decline in cladoceran density; a preponderance of blue-green algae, especially colonial forms with mucilaginous sheaths; a shift from numerous, relatively small plankton algal taxa to fewer but larger forms; degraded water quality.     

Comparative Growth of Diploid and Triploid Asian Catfish Clarias macrocephalus in Thailand

Wild caught Asian catfish were spawned manually following HCG injection, and a portion of the eggs were subjected to cold-shock at 4 C for 15 min within 2-min post-fertilization. Nuclear diameter measurements of cold-shocked fish revealed that 96% were triploids (3N), while non-shocked fish were all diploids (2N). During larval and fry culture (first 26 d), triploid fish mortality was =50%, while diploid mortality was =25%. Following 8-mo culture in tanks at three stocking densities, triploid fish survival was significantly greater ( P < 0.05), than diploids, with 84.0% and 57.3%, respectively. Triploid live weight was also significantly greater than diploids, with 69.2 and 45.9 g averages, respectively. Ninety-two percent of diploids had welldeveloped gonads after 8 mo; whereas none of the triploids had mature gonads. Gonads were undifferentiated with 31% of the triploids. These sexually undifferentiated fish had greater growth rates than male or female triploids, and greater growth than all diploids. Carcass weight (gutted) of triploids was 95.8% of live weight, compared with 92.5% for diploids. Lastly, triploids had very few deformities compared with diploids, with 1.3% and 17.6%, respectively. Deformities included curved spines, and humped backs just posterior of the head.     

Effect of Pretreatments on Hydrolysis Efficiency and Antioxidative Activity of Hydrolysates Produced from Bighead Carp (Aristichthys nobilis)

ABSTRACT

Effect of pretreatment methods including ultrasonication (US), microwave (MW), and ultrafine milling (UM) on hydrolysis efficiency and antioxidative activity of peptides produced from bighead carp were investigated. The UM peptides showed higher hydrolysis efficiency (higher degree of hydrolysis, nitrogen recovery, and oligopeptide yield; narrower molecular-weight distribution), and higher 1,1-dipheny1-2-pycrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfomic acid) diammonium salt (ABTS) radical scavenging activities, and metal chelating activities than US and MW peptides. The hydrolysis efficiency and antioxidative activity of UM peptides could remain relatively high even when the substrate concentration increased up to 50%. In conclusion, ultrafine milling may be a suitable pretreatment method in the production of peptides.     

Growth and Food Habits of Cage-Cultured Bighead Carp x Silver Carp Hybrids in Ponds of Varying Trophic Status

Four 20m³ cages stocked with 120 bighead carp x silver carp hybrids per cage were placed in each of four ponds varying in trophic status from mesotrophic to hypereutophic. Fish were cultured, without feeding, from 13 March to 1 Octorber 1987. Fish in the mesotrophic pond survived but lost weight (-0.37 g/fish/d). The mesotrophic pond produced insufficient food to sustain fish growth. Maximum fish growth rate occured in the two eutotrophic ponds (6.61vand 7/04 g/fish/d). Fish growth in the hypereutrophic pond was about one-half (3.64 g/fish/d) that in the two eutrophic ponds. Guy analysis of fish in the hypereutrophic pond revealed consumption of larger quantities (P < 0.05) of colonial blue-green algae that were apparently poorly digested and less (P < 0.05) zooplankton (primarily cladocerans) than was found in fish from the eutrophic ponds.     

千岛湖有机鳙鱼网箱暂养的体重损耗研究

本文研究了上市前的网箱暂养对千岛湖所产、经OFDC有机认证的鳙鱼的体重、丰满度及体重损耗率的影响。结果表明 ,在 6 7月水温逐渐升高 (2 4 30℃ )阶段 ,暂养鳙鱼的体重和丰满度均随时间呈指数式下降 ,而在 10 11月水温逐渐下降 (2 2 17.5℃ )阶段则随时间呈对数式下降。在不同暂养密度下和不同季节 ,鳙鱼的体重损耗率呈现不同的变化态势 :在 6 7月当暂养密度为 10 0尾 /箱 (2 72 7.6g/m3 )时 ,体重损耗率随时间呈指数式增加 ,而其他各高密度暂养组的体重损耗率均随时间呈对数式增长 ;在 10 11月 ,各密度组鳙鱼的体重损耗率均随暂养时间呈抛物线式变化 ,出现最大损耗率的时间各组均在 2 12 6d之间 ,最大损耗率出现的时间各组之间无显著差异 (P >0 .0 5 ) ,但损耗率极值的大小与暂养密度有一定关系。为了使暂养过程中的损耗降到最低 ,鳙鱼的适当暂养密度在 6 7月以 10 0尾 /箱 (2 72 7.6 g/m3 )左右为宜 ,而在 10 11月可以增加到 15 0尾 /箱 (35 97.2g/m3 ) ;暂养时间不宜超过 2 0d。     

鳙幼鱼4种典型游泳状态特性研究

研究鳙(Hypophthalmichthys nobilis)游泳行为特性与水流流速变化的响应关系,补充四大家鱼游泳特性指标,为四大家鱼资源保护、鱼类洄游通道建设提供参考依据。试验水温(23±0.5)℃,鳙幼鱼体长5.0～9.0 cm、体重2.5～11.5 g,游泳水槽300 mm×5 mm×75 mm,体积5 L。结果表明该体长范围鳙幼鱼的平均临界游泳速度为(0.468±0.161)m/s,平均突进游泳速度为(0.672±0.154)m/s,且绝对临界游泳速度和绝对突进游泳速度均随体长的增加而线性增加,相对突进游泳速度随体长的增加而线性减小;绝对突进游泳速度与绝对临界游泳速度存在如下关系：U_burst=1.922U_crit+56.726;鱼类游泳行为随水流流速变化存在4种游泳状态(顶流前进、顶流后退、顶流静止、顺流而下)相互穿插现象。以鳙幼鱼为过鱼对象的鱼道池室主流流速为16.0～46.5 cm/s,鱼道高流速区的竖缝、孔口等最佳流速为46.5～85.4 cm/s。