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本项目于1993～1995年在河池地区大化、岩滩电站库区及红水河、龙江河实施。3年累计设置网箱10274箱，面积244660m^2，总产成鱼8204．03t，平均单产33.55kg/m^2,平均成活率82．29％，其中草鱼成活率73．71％，其他鱼成活率87．74％。项目总产值8418.22万元，年均创利税1086．64万元，投入产出比1l1．97。在网箱养殖常规品种的同时，还养殖名优品种斑鳗24箱。面积731m^2，平均单产28．32kg/m^2。 相似文献
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1996年，连城县大石岩水库，进行了小体积网箱养殖团头综试验，经152天的养殖、16个计体积40m3的小网箱，总产团头访4410．5kg、平均每立方米产鱼110．3kg、出箱鱼平均规格达496克／尾，平均养殖成活率为89％，总产值74978．5元、总利润达33477.5元、平均每立方米获利837元。取得较好的养殖效果和经济效益。现把试验情况总结如下。一、材料与方法1．试验网箱为聚乙烯网箱、网目3cm，在底网附加密网布上至四边墙网15cm。4m3网箱规格为2X2X1．2m、8个，1m3网箱规格为1X1X1．2m、8个。采用简易毛竹网箱框架，投饵管为镀锌铁皮制成的内径10cm… 相似文献
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封闭式循环水养殖牙鲆鱼技术初步研究 总被引：8，自引：0，他引：8
将新功能滤料、高效混合净水菌团、水质自动监测及控制3项关键技术及配套设备用于封闭式循环水养殖牙鲆鱼。结果表明，封闭循环组成活率可达到90％－95．1％，平均产量为32．2kg/m^2。较对照组养殖密度增加75．6％－102．7％，成活率提高14％－17％，平均产量增加145％－187．5％。充分利用有限的水体，避免海水二次污染，利于环境保护。 相似文献
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淡水苏眉鱼中文学名淡水波纹鱼，具有环境适应能力较强、耐低氧、生存温度范围广、抗病力强、成活率高、杂食性、肉质佳、生长迅速等优点。雄鱼生长速度大于雌鱼，一般情况下性成熟期为2～3年，是很好的淡水养殖品种之一。2012年5月底引进经淡化的苏眉鱼苗2．25万尾试养，大棚池塘总面积5000m^2，至2014年4月初全部试养成功，养成规格0．9-1kg／尾，共上市苏眉鱼1．73万kg，成活率达81．2％。取得了较好的养殖经济效益，平均利润达30～45元／m^2。现将其试养技术介绍如下： 相似文献
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2005年网箱培育长吻能冬片鱼种，应用5m×5m×3．5m的网箱，放养规格为3～4cm／尾的长吻鲍夏花鱼种，放养密度56～790尾／m^2，投喂粗蛋白为42％～46％的配合饲料，经7个月养殖，长吻鲍鱼种平均规格达165g／尾，成活率82．5％，单产9kg／m^2，饲料系数1．26，投入产出比1：2．04；2006年网箱养殖长吻脆商品鱼，应用5m×5m×4．5m的网箱，放养规格为133g／尾左右的长吻能冬片鱼种，放养密度32～50尾／m^2，投喂粗蛋白为42％～43％的配合饲料，经6个半月时间的养殖期，养成个体规格在0．5kg／尾以上的长吻娩商品鱼比例达86％以上，成活率82．6％～87．0％，饲料系数1．38，单产22．83～26．24kg／m^2，投入产出比1：1．59。 相似文献
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从收购天然鱼种进行驯化养殖入手，经3年池塘培育，获三角鲤亲鱼1676尾，亲鱼培育成活率达96．1％；对性腺发育进行了研究，结果表明：三角鲤为每年1次产卵类型。雌鱼的性成熟年龄为3冬龄，雄鱼则为2冬龄；性成熟雌鱼卵巢系数大致变动在1．696—12．7％，全年平均约7．5％；卵径变动范围50～1450μm，平均762／μm；相对怀卵量为4．67—6．70万粒／kg，平均5．98万粒／kg；适宜的繁殖生产季节在3月初到4月底。 相似文献
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从收购天然鱼种进行驯化养殖入手，经3年池塘培育，获三角鲤亲鱼1676尾，亲鱼培育成活率达96％；对性腺发育情况进行了初步研究，结果表明：三角鲤属每年1次产卵类型，雌鱼的性成熟年龄为3冬龄，雄鱼则为2冬龄；性成熟雌鱼卵巢系数大致变动在1．6％～12．7％，全年平均约7．5％；卵径变动范围50～1450μm，平均762μm；相对怀卵量为4．67～6．70万粒／kg，平均5．98万粒／kg；适宜的繁殖生产季节在3月初到4月底。 相似文献
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流水条件下利用网箱驯化培育黄颡鱼鱼种和进行成鱼养殖,经驯化后鱼苗摄食人工膨化配合饲料取得成功,鱼种培育成活率达84．5％,成鱼养殖成活率达93．8％;密度为1000尾／m2。放养规格为180尾／k的养殖模式效果最显著。试验面积80m2,产鱼80．2kg／m2,产值2025．6元／m2,创利422．2元／m2。 相似文献
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褐菖鲉生长缓慢，在浙江南麂海域2001年4月30日放养0．9g的苗种，至2001年6月7日达8.3g，当年底达24.8g，2003年6月26日达112.3g。总养殖成活率20．1％，平均日增重0．14g，平均增重率0．62％。秋末至夏初低水温期是其主要生长期。冬春季养殖成活率高于秋夏季，第一年夏季养殖成活率低，仅28．1％。饵料系数为3．6，食性为杂食性，对网箱具有明显的清洁作用。在9～13％低水温期亦会摄食与生长。适温下限在7．2℃以下，适温上限在25．6℃以下。养殖方式以混养为宜，生产安排以10月份收购502左右的苗种养至翌年6月达100g以上规格出售为好，该养殖模式能避开台风期与高温期。褐鲉鲇肉质细嫩，味道鲜美，近年颇受人们欢迎，其经济价值高，且我国沿海褐菖鲇苗种资源丰富，养殖开发前景良好。 相似文献
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L. -G. Lnnstrm R. Rahkonen T. Lundn M. Pasternack J. Koskela A. Grndahl 《Aquaculture (Amsterdam, Netherlands)》2001,200(3-4):271-284
As indicated by market demand and cultivation prospects, the whitefish (Coregonus lavaretus L.) has the potential to become an important alternative to rainbow trout in fish farming in Finland. The fish processing industry has called for a fish species having non-pigmented flesh, and there is a long tradition of whitefish farming for stocking purposes in Finland. However, cultivation in net cages in the brackish water of the coastal area exposes fish to vibriosis (Listonella (Vibrio) anguillarum) and furunculosis (Aeromonas salmonicida salmonicida). Hence, profitable whitefish farming requires the efficient control of both of these diseases. The efficacy of vaccination (Apoject 1800®) was studied in the laboratory using challenge tests and by monitoring specific antibody production (ELISA) and the blood leucocyte pattern. The fish (22 g) were vaccinated at 15°C and the immunity developed during 8 weeks prior to challenge with vibriosis (1.8×105 cfu) and 12 weeks prior to challenge with furunculosis (4.9×102 cfu). The challenge was performed by i.p. injection. Side-effects around the injection site were studied 16 weeks post-vaccination. The immune system of the whitefish responded well and vaccination gave good protection against vibriosis and furunculosis. The RPS was 100% following the Vibrio challenge and 99% following the Aeromonas challenge. The antibody levels continued increasing in the vaccinated group throughout the study period. Lymphocyte and neutrophil counts were elevated in vaccinated compared to non-vaccinated fish at 8 weeks post-vaccination, but not after 16 weeks. Vaccination produced weak adhesions around the injection site in 42% and minor pigmentation in 9% of the 65 fish examined. 相似文献
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M. A. R. Mridha M. A. Hossain M. Nahiduzzaman M. S. Uddin 《Journal Of Applied Aquaculture》2017,29(2):152-166
This study investigated the effects of supplementary feeds with different crude protein (CP) levels on the growth and economic performances of sex-reversed Nile tilapia (Oreochromis niloticus) reared in a rain-fed rice–fish ecosystem for a period of 120 days. There were four treatments—namely, traditional feed (21% CP), formulated feed (26% CP), commercial feed (30% CP), and control (no feed was used)—with three replicates per treatment. Fish (30.04 g) were stocked in ditches at a rate of 0.5 fish m?2 considering the total area and fed one of the tested feeds twice daily at the rate of 2%–5% of body weight. Water-quality parameters of the ditches were monitored fortnightly, and these parameters were found suitable for fish farming. Organic matter, total nitrogen, and available phosphorous in soil were increased significantly (P < 0.05) in the feed treatments after fish cultivation. Highly significant weight gain and SGR were observed with fish fed the commercial feed as compared with other treatments. The highest benefit-cost ratio (2.15) was found in the control, followed by formulated feed (1.90), but in the case of numerical net return, it was the opposite. However, commercial feed showed the lowest benefit-cost ratio (1.67) due to higher feed cost than other supplementary feeds. Therefore, this study suggests that fish fed with a formulated feed (26% CP) produced significantly higher net economic return in the rice–fish farming system. 相似文献
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Abstract. Purification and in vitro cultivation techniques were developed for the fish haemoflagellate, Trypanosoma danilewskyi. The parasites were isolated and purified from the peripheral blood of experimentally infected goldfish, using a combination of Ficolt-paque gradient centrifugation to remove fish red blood cells and in vitro incubation to remove the remaining fish leucocytes. A serum-free culture medium for T. danilewskyi supported both short- and long-term cultivation of the haemoflagellates. The serum-free medium is a mixture of reagents available commercially: Leibovitz's L-15 medium, Dulbecco's Modified Eagle Medium and Hank's balanced salt solution. The doubling time was calculated to be 44.4 × 7.8h. Typically, a two- to five-fold increase in the number of cultured parasites was observed on day 7 after subculture with 1 × 106 and 5 × 105 trypanosomes ml−1 , respectively. When administered to fish, the in vitro -derived parasites caused an infection and pathology whose characteristics were similar to those observed following infection with trypanosomes obtained from infected goldfish. The freshly isolated and in vitro -grown parasites were successfully cryoprescrvcd in the culture medium containing 10% glycerine at −80°C for at least 3 months. Although the viability of the parasite decreased by 40–50% after thawing, cryoprcserved parasites retained the ability to infect goldfish.
Correspondence: Dr M. Belosevic, Associate Professor, Department of Zoology, CW-312 Biological Sciences Building, University of Alberta, Edmonton, AB, Canada T6G 2E9. 相似文献
Correspondence: Dr M. Belosevic, Associate Professor, Department of Zoology, CW-312 Biological Sciences Building, University of Alberta, Edmonton, AB, Canada T6G 2E9. 相似文献
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通过大弹涂鱼土池高密度精养试验,结果表明：4—5月份每667m^2放养规格为5．5～6．5cm和8cm左右苗种40kg（10000尾）,经过6～7个月饲养．于10月底陆续起捕至农历12月底结束,每667m。鱼产量达到上市规格的有116kg（2900余尾）,未达到上市规格的有53．2kg（5350余尾）留下继续养殖使其进一步生长。养成成活率达82．5％。同时探讨了放养前大弹涂鱼精养塘的处理、苗种放养、池塘管理．收获与销售等技术环节。 相似文献
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Intensive recirculating aquaculture relies on biofilters to sustain satisfactory water quality in the system. Fluidized bed and immobilized cell technologies were used to remove ammonia from the water and maintain fish health. A high‐rate nitrifying fluidized bed biofilter combined with valveless filter was designed for use in a recirculation aquaculture system (RAS). The suspended solids produced during fish culture could automatically be removed using a valveless filter. Natural porosity with fitting proportion, steady fluidization and expanding rate was chosen as the fluidized carrier. The technology of bacterial separation and cultivation was used. The immobilized Rhodopseudomonas palustris (R. palustris) produced through a biotechnologically embedding medium is suitable for fish and could help prevent diseases. Nitrification was promoted through the selective rearing of nitrobacteria in a fluidized bed biofilter. Water quality was improved using fluidized bed biofilter and immobilized R. palustris in the RAS. In addition, the proposed system was able to reduce costs. Maximum fish load was 45 ± 3 kg m?3 in the closed recirculating water fish culture system, and water use was reduced by 80–90%. The total ammonia nitrogen removal rate of the technology was 80–95%, and nitrite N removal rate was above 80%. 相似文献
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Leila Hayashi Nair S. Yokoya Srgio Ostini Ricardo T.L. Pereira Elisabete S. Braga Eurico C. Oliveira 《Aquaculture (Amsterdam, Netherlands)》2008,277(3-4):185-191
The potential of the red alga Kappaphycus alvarezii to remove nutrients was tested to treat effluents of Trachinotus carolinus fish cultivation, and the production of carrageenan in this condition was analyzed. Experiments were conducted in four tanks of 8000 L with approximately 1200 fishes of 30 g each integrated with three tanks of 100 L with 700 g of K. alvarezii, as initial biomass per tank. Seawater was re-circulated between tanks with seaweed and with fish. As a control, three tanks with seawater circulating in an open system were utilized. Seawater samples were collected daily for 10 days and concentrations of nitrate, nitrite, ammonium and phosphate were determined in the inflow and outflow water of the tanks. Significant differences between both collecting points were considered as nutrient removal by the seaweed. Growth rates and carrageenan yields were also analyzed in seaweed cultivated in seawater and in effluents. Growth rates of seaweed cultivated in tanks were lower than those obtained in open sea and in laboratory cultivation. Effluents had concentrations of nitrate and nitrite ca. 100 times higher than in the control. Maximum values of nutrient removal on effluents were: nitrate = 18.2%; nitrite = 50.8%; ammonium = 70.5% and phosphate = 26.8%. All plants survived throughout the experimental period, but some developed “ice–ice”, a disease associated with physiological stress. After the experimental period, some plants selected and cultivated in open sea presented higher growth rates in 40 days, indicating nutrient storage. No significant differences between carrageenan yields of K. alvarezii cultivated in seawater and in the effluents were observed. Our results show that K. alvarezii can be utilized as a biofilter for fish cultivation effluents, reducing the eutrophication process and can also be processed for carrageenan production, which provides an additional benefit to the fisheries. 相似文献
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以鳜(Siniperca chuatsi)选育群体为实验材料,在易驯食与不易驯食鳜转录组Unigene数据库中共预测到4809个SNP位点,其中胃蛋白酶基因(pepsinoge, pep)和生长激素基因(growth hormone, gh)均为转录组筛选获得的鳜驯食性状候选基因,本研究将候选基因上的多态SNP位点在易驯食和不易驯食鳜群体中进行基因分型,并与鳜驯食性状进行关联分析。在易驯食与不易驯食的鳜群体中共发现5个单核苷酸(SNP)多态性位点,有效等位基因(N_e)在1.1959～1.7001,观测杂合度(H_o)和期望杂合度(H_e)分别分布于0.1800～0.3585和0.1655～0.4160,多态信息含量(PIC)为0.2477,全部位点都属于中度多态性位点。结果表明SNP位点pep-A T/C中2种基因型TT和CT与鳜驯食性状呈高水平显著相关(P0.05),组合得到的3种基因型Genotype1(CT,CC/CT/TT,AA,AA,TT)、Genotype2(TT,CC/CT/TT, AA, AA, TT)和Genotype3(TT, CC, AA, AA, TT)也与鳜驯食性状呈高水平显著相关(P0.05),显著影响鳜驯食性状表型,其中Genotype2相关性最高,可作为最优基因型个体进行选育。本研究在鳜pep和gh基因中鉴定出与驯食性状呈显著关联的SNP分子标记,为加快易驯食鳜新品种的基因辅助选育提供有效的SNP分子标记。 相似文献