芬兰虹鳟鱼同工酶分析

运用聚丙烯酰胺凝胶电泳法对芬兰虹鳟肌肉(M)、心(H)、肝(L)、肾(K)、眼(E)等5种组织中的乳酸脱氢酶(LDH)、乙醇脱氢酶(ADH)、苹果酸酶(ME)、葡萄糖-6-磷酸脱氢酶(G6PDH)、过氧化物酶(POD)和酯酶(EST)进行了初步研究,并对各种酶的同工酶位点及酶谱表型进行分析。结果表明,除酯酶外,其他5种同工酶均表现出不同程度的组织特异性。同工酶表型种群遗传学研究发现,6种同工酶共记录15个基因座位,多态座位比例(P=40%)略高,位点有效等位基因数(Ne=1.4)较大,表明芬兰虹鳟种群遗传多样性偏高。     

Incidence of Pathogenic Microorganisms in Aquacultured Rainbow Trout (Oncorhynchus mykiss)

ABSTRACT

Quantitative levels of six known pathogens (Listeria monocytogenes, Clostridium botulinum, Salmonella species, Vibrio cholerae, Yersinia enterocolitica, and Y. pseudotuberculosis) and aerobic plate counts were measured at five aquaculture facilities. The farmed rainbow trout (Oncorhynchus mykiss) and trout fillets were sampled at two different growing seasons to monitor for microbial hazards. Listeria spp. was identified in both whole trout and trout fillets from all five facilities sampled from both growing seasons. Presumptive Clostridium botulinum spores were also identified from all five facilities for both seasons. The growing season did not affect pathogen levels and there was no evidence that any one aquacultural system was superior to the others. Salmonella spp., Vibrio cholerae, and Yersinia spp. were not isolated from any of the trout samples analyzed.     

Growth Rate, Maturation Level and Flesh Quality of Three Strains of Large Rainbow Trout (Oncorhynchus Mykiss) Reared in Estonia

Three all-female strains of large rainbow trout imported to Estonia (Danish, Finnish and Donaldson strain) were evaluated in a communal rearing experiment in tanks. The fish had been reared on different fish farms before the experiment started and they had an initial weight of 400–500 g. There were no significant genetic differences between the investigated strains on the basis of three allozyme loci. The total weight gain of the strains during the trial was similar but differences were revealed between seasons. The growth rate of the Finnish trout was high during the first autumn but decreased during the second summer of the trial, probably due to infestation by eye fluke Diplostomum sp. The strains differed in the percentage of immature fish and in the level of gonad development at the age of 2.5–3 years. The Donaldson strain had the highest number of immature fish of the studied strains. Mature females of the Finnish strain had the smallest gonads but also the lowest percentage of immature fish. The level of maturation was the main factor determining the quality – slaughter yield and flesh color.     

Land cover influences on juvenile Rainbow Trout diet composition and condition in Lake Michigan tributaries

Watershed development may alter tributaries in ways that influence the growth and development of juvenile fish. For Rainbow Trout Oncorhynchus mykiss, the extent of land cover influence on the diet composition of stream‐residing juveniles is still an open but important question, particularly given their broad global distribution. Our study evaluated the effect of land cover on diet composition and condition metrics of juvenile Rainbow Trout in Lake Michigan tributaries. Juveniles were collected in the fall of 2014 and 2015 from 18 sampling locations across the Lake Michigan basin and included a wide variety of land cover types. Multivariate statistical procedures were used to quantitatively score sites along axes that maximized variation in land cover and diet composition. Subsequently, Spearman's rank correlations were used to test for significance of correlations between (a) land cover and diet composition, (b) land cover and fish condition, and (c) diet composition and fish condition. Our results indicated that land cover had an influence on the diet compositions of juvenile Rainbow Trout, but neither land cover nor diet composition had a significant influence on Rainbow Trout condition. These findings contrast with previously published work focusing on the growth responses of other fish species and provide insight into the plastic nature of Rainbow Trout. Further, we discuss potential ways in which fish may mitigate the effect of land cover changes as they are transmitted through stream food webs; however, the magnitude of the mitigation likely varies among fish species.     

热休克诱导全雌虹鳟三倍体

以虹鳟二倍体的伪雄鱼为父本（遗传型为xx），探讨了采用热休克方法阻止第二极体排放诱导全雌虹鳟三倍体的适宜条件。结果表明：虹鳟三倍体诱导率明显受处理温度、起始时间以及持续时间等因子的影响。在孵化水温为6．5℃，卵子受精后20min经26℃热处理20min，孵化率为64．62％，三倍体诱导率为86．67％；卵子受精后lOmin经26℃热处理20min，三倍体诱导率为100％，但孵化率仅为3．87％。受精卵经26℃处理的诱导效果好于24℃和28℃的（P〈0．01）。     

Production Characteristics of Rainbow Trout,Oncorhynchus mykiss and Brook Trout,Salvelinus fontinalis Under Seasonal Pond Conditions

Abstract

The production characteristics of juvenile rainbow trout, Oncorhynchus mykiss and brook trout, Salvelinus fontinalis were compared under winter pond conditions. Juvenile rainbow trout (55.1 ±1.5 g) and brook trout (28.9 ±0.4 g) were stocked at a density of 8,750 fish/ha into six 0.04-ha ponds. After 163 days, survival, growth, and feed conversion were similar (P >0.05). The results of this study suggest that brook trout may attain growth rates similar to rainbow trout under winter pond conditions in temperate regions of North America.     

虹鳟营养需求的研究进展

简要介绍了近年来国内外虹鳟的营养研究,包括蛋白质、脂肪、维生素、矿物质等方面,提出一些虹鳟养殖中的注意事项,为虹鳟养殖、饲料生产和科研开发提供参考。     

盐度对金鳟幼鱼肌肉品质的影响

探讨了盐度驯化对金鳟(Oncorhynchus mykiss)幼鱼肌肉品质的影响.结果表明,盐度驯化对金鳟肌肉硬度、胶着性和咀嚼性无显著影响,但盐度为32时,回弹性最高,盐度为24时,金鳟肌肉的白度最高,显著高于对照组,亮度无显著性差异,但盐度为16时,肌肉颜色偏红.盐度驯化对金鳟肌肉水分、粗脂肪和粗蛋白含量无显著影响...     

荧光染色法检测虹鳟精子质量

本实验运用三种荧光染色方法对虹鳟精子的质量进行检测,并探讨荧光染色对虹鳟精子质量评价的可性及意义。在生殖季节采集虹鳟精液,分别进行Hoechst33342/碘化丙啶双染,吖啶橙染色及罗丹明123/碘化丙啶双染,然后将其制成涂片荧光显微镜下观察。经荧光染色的虹鳟精子质膜完整,DNA完整,可明显分辨出活体和死亡精子,线粒体膜功能正常精子的比率分别为90.7%、98.7%和96.4%。综上所述,结合三种检测方法可以简便快速地测定虹鳟精子的质量。     

Use of Onion (Allium cepa) and Garlic (Allium sativum) Wastes for the Prevention of Fungal Disease (Saprolegnia parasitica) on Eggs of Rainbow Trout (Oncorhynchus mykiss)

This study was designed to prevent fungal disease (Saprolegnia parasitica) that occurs on rainbow trout eggs (Oncorhynchus mykiss) by using wastes of onion (Allium cepa) and garlic (Allium sativum) plants. For this purpose, fertilized rainbow trout eggs were exposed to garlic skin, garlic stem and onion skin aqueous methanolic extracts by bathing in concentrations of 0.4, 0.8, 1.6 and 3.2 g/L, whereas the control group was left untreated. The larvae in all groups were monitored until they become free-swimming larvae, the number of eggs died due to fungus was recorded, and the data obtained from experimental groups and control group were compared. As a result, it was determined that onion skin had no effect on the number of eggs that died due to fungus (p > .05), while garlic skin and garlic stem extracts significantly reduced the number of fungal infestations without affecting the number of live larvae or the embryological development of the eggs (p < .05). In light of these data, we conclude that garlic skin (0.4, 0.8, and 1.6 g/L) and garlic stem (0.8 and 1.6 g/L) aqueous methanolic extracts are effective at preventing Saprolegnia parasitica infestation on rainbow trout eggs and may be used in aquaculture.     

虹鳟鱼核型及DNA含量分析

采用植物血球凝素（ＰＨＡ）体内注射、肾组织细胞短期培养、常规空气干燥法制备了虹鳟的染色体，并进行了核型分析。虹鳟二倍体的染色体为６０条，其核型为２２ｍ＋１ｓｔ＋７ｔ，ＮＦ＝１０４。以外周血红血球为样本，鸡红血细胞为对照，用美国产的ＦＡＣＳｔａｒｐｌｕｓ流式细胞仪测定了虹鳟的二倍体细胞核的ＤＮＡ含量，其ＤＮＡ含量为鸡血对照的１．５１倍，绝对含量为３．４７±０．２１ｐｇ／Ｎ。     

金鳟养殖试验

在辽宁省凤城市四门子镇新农水产养殖场进行金鳟鱼的养殖试验。养殖用水为当地山涧冷泉水,养殖水面为100m2,共投放单重20g的鱼种12000尾。试验期间,金鳟生长良好,成活率为99%,利润为12万元。试验结果表明,金鳟作为良好水环境的指示生物,具有极高的生态附加值,可以为进一步开发辽东山区的生态资源和冷水资源提供有效途径,为促进生态经济的协调发展奠定良好基础。     

Determination of Salt Diffusion Coefficient in Rainbow Trout (Oncorhynchus mykiss)

ABSTRACT

The diffusion properties of sodium chloride in rainbow trout muscle during dry salting at 10°C were investigated. The average initial dry matter content of the samples increased from 27.80 ± 0.10 to 36.01 ± 0.16%, and the average salt content increased to 17.98 ± 0.38 g NaCl/100 g dry matter at the end of the 10-h dry salting process. The analytical solution of Fick’s second law considering one-dimensional diffusion through an infinite slab was used to calculate effective salt diffusion coefficients (D_eff). The D_eff values in rainbow trout fillets decreased with increasing salting time and ranged from 6.64 × 10^?10 to 16.45 × 10^?10 m²/s.     

三倍体虹鳟(Oncorhynchus mykiss)血细胞发生的形态学研究

观察和测定了三倍体虹鳟(Oncorhynchus mykiss)肝脏、脾脏、头肾和外周血液血细胞的发生过程。结果显示:三倍体虹鳟外周血红细胞具有分裂的能力,外周血液是其进一步发育成熟的场所,其进一步发育成熟有核质非同步分裂(核分裂先于质分裂呈双核型)和核质哑铃型同步分裂两种形式。外周血液中未成熟红细胞、单核细胞、淋巴细胞和粒细胞细胞比例分别为5.81%、4.14%、4.52%和3.38%,其4类未成熟细胞比例明显高于造血器官;外周血液中成熟红细胞为69.6%,与造血器官成熟红细胞的比例无显著差异;外周血中单核细胞、淋巴细胞和粒细胞细胞比例分别为6.60%、4.71%和1.24%,三类细胞比例明显低于造血器官(头肾中单核细胞除外)。     

Taurine Supplementation of All-plant Protein Diets for Rainbow Trout (Oncorhynchus mykiss)

Abstract.— Taurine has been demonstrated to be conditionally indispensable for several carnivorous fish species. Current trends in trout production include decreasing levels of fish-meal content in feeds, along with faster growing strains of fish. Taurine may be a limiting nutrient in support of elevated planes of growth for rainbow trout. A 9-wk feeding trial was conducted using a factorial treatment design with protein source (fish meal or plant) and taurine supplementation (four levels) as the main effects. The fish-meal diet series included 23% herring meal and contained 1.76% total sulfur amino acids (TSAA). The plant diet series did not contain any animal proteins and substituted protein from soy protein concentrate in place of the herring-meal protein and contained 1.5% TSAA. Taurine was supplemented at 0, 5, 10, and 15 g/kg dry diet to each of the diets in the plant series and the fish-meal series of diets. All diets were formulated to contain 43.8% crude protein and 20% lipid with an estimated physiological fuel value of 4.2 kcal/g. Fifteen fish were stocked in each of 24 tanks with a mean initial weight of approximately 26.8 g per fish. The unsupplemented fish-meal diet contained 2 g/kg taurine, and the unsupplemented plant diet had taurine levels below the detection limit of 0.1 g/kg diet. Taurine supplementation improved growth, feed conversion ratios, protein retention efficiencies, and energy retention efficiencies of fish fed the plant protein diets. No effects of taurine supplementation were observed for these response factors in fish fed the fish-meal series diets. This study demonstrates that taurine supplementation may be necessary for rainbow trout fed plant-protein-based feeds.     

Effect of Stocking Density on Growth,Yield, and Costs of Producing Rainbow Trout,Oncorhynchus mykiss,in Cages

Abstract

Rainbow trout, Oncorhynchus mykiss, were raised in culture cages (1 m³) to determine the effect of stocking density on growth, survival, and percentage of market-size fish. Large fingerling rainbow trout (20-25 cm, 232 g average weight) were stocked into six cages located in a 0.4-ha pond. Two stocking densities (100 or 200 fish/cage) were used, and fish were grown for 140 days (2000-April 2001). Average total harvest weight (35.0 kg) in the low-density cages was approximately one-half the average total harvest weight (61.2 kg) in the high-density cages. Average weight gain (11.7 kg to 15.1 kg) and feed conversion (1.2 to 1.5) were also smaller for the low-density cages. Average survival was 96.7% for the low-density cages and 94.2% for the high-density cages, with the percentage of market-size fish (< 29 cm) averaging 50.3% and 52.0%, respectively. Production costs for the actual experiment and the revenues from fish sold at the end of the study were collected. An enterprise budget based on the experimental results for the two densities was developed to determine if a culture operation of this size would produce a net return. Production costs and revenues from the experiment resulted in a large negative return (-$3,124) and high breakeven price ($13.53/kg).     

虹鳟功能性饲料添加剂研究进展

功能性饲料添加剂能够提高养殖虹鳟的营养成分和品质、减少鱼药的应用、增强其免疫力、提高经济效益,是目前虹鳟养殖研究的热点。文章从饲料添加剂的主要功能角度出发,按照品质提升、免疫增强、促生长等类别,对国内外虹鳟功能性饲料添加剂的研究现状进行了总结,并分析了其中存在的难点和问题。     

Prediction of the Weight of Aquacultured Rainbow Trout (Oncorhynchus mykiss) by Image Analysis

Prediction relationships between weight and image features were established with a high correlation for whole aquacultured rainbow trout. Three hundred fish from three different farms were used. The fish were temporarily removed from the raceway, anesthetized, and their picture was taken by a digital camera. A reference square of known surface area and color was placed beside the fish. The fish were then returned to the raceway alive. The image was analyzed, and the view area of the fish was calculated using the area of the reference square. The average color of the fish was also determined (L*, a*, and b* values). The following equations were used to fit the view area (X) vs. weight (Y) data: linear, power, and second order polynomial. The R² values for the used equations were: linear = 0.98; power = 0.99; polynomial = 0.98. Image analysis can be used reliably to predict the weight of whole aquacultured rainbow trout. In addition, color and other visual attributes can be objectively determined by image analysis to sort by visual quality.     

Growth and Survival of Intrastrain and Interstrain Rainbow Trout (Oncorhynchus mykiss) Triploids1

Triploid rainbow trout exhibit improved survival and extended growth during sexual maturation, compared to their diploid counterparts. However, there have been few benefits demonstrated prior to sexual maturation. This study was undertaken to investigate the possibility of improving growth and survival parameters in triploids through interstrain crosses. Triploids were induced by heat shocking fertilized eggs from intra- and interstrain crosses of two rainbow trout strains. The four triploid groups and their diploid counterpart groups were reared to 233 days post-hatching and analyzed for growth and survival characteristics. Compared with diploids, triploids had significantly (P < 0.05) higher mortalities during the first 100 days post-fertilization, primarily just prior to and after hatching. However, during the remainder of the study triploids exhibited significantly (P < 0.05) lower mortalities than diploids. During the first 50 days of rearing all four triploid groups were significantly shorter and lighter than their diploid counterparts. The growth of the triploid groups later in the study varied considerably. At the conclusion of the rearing phase, one interstrain triploid group was significantly (P < 0.05) longer than its diploid counterpart, although not significantly heavier. The other triploid groups were either significantly smaller than, or equal to the diploids. Analysis of variance indicated that the growth of triploid rainbow trout was significantly affected by maternal strain effects. These results suggest that the use of specific strains and crosses may improve the growth of triploid rainbow trout.