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1.
锯缘青蟹大眼幼体与凡纳滨对虾混养试验 总被引：1，自引：0，他引：1
利用3口池塘共1.14 hm2进行锯缘青蟹大眼幼体与凡纳滨对虾的混养试验,投放锯缘青蟹大眼幼体8500只,凡纳滨对虾苗2.03×105尾,经96~129 d的养殖,收获锯缘青蟹729.1 kg,凡纳滨对虾2804.3 kg;锯缘青蟹平均312 g/只,凡纳滨对虾57.5尾/kg;锯缘青蟹大眼幼体成活率27.5%,凡纳滨对虾成活率79.4%。试验结果表明,锯缘青蟹大眼幼体可以直接投入池塘中与凡纳滨对虾混养,将为今后大规模发展锯缘青蟹养殖摸索出一条有效途径。 相似文献
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锯缘青蟹 (ScyllaserrataForskal)隶属节肢动物门 ,甲壳纲 ,十足目 ,梭子蟹科 ,青蟹属。其分布较广 ,在温带、亚热带均有分布 ,我国的上海以南沿海均有分布。为把青蟹这一优良品种引到北方养殖 ,1 996年我所承担了山东省科委的科研项目“青蟹引进技术的研究”。经 6年的研究探索 ,圆满完成课题下达的各项科研指标。本文重点就1 997年锯缘青蟹的精养以及与中国对虾混养情况并 6年来的养殖推广情况总结如下 :1 养殖与管理1 .1池塘情况利用本所现有的对虾养成池进行青蟹的精养及与中国对虾的混养试验。精养池塘 1个 ,规格为 1 .5亩 ,深 1 .8m… 相似文献
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锯缘青蟹(俗称黄格蟹)是畅销国内外市场的高档水产品之一.自2002年起,上虞市渔民在海涂九六丘北塘外陆基围塘养殖锯缘青蟹,至今养殖面积已达4000余亩.2006年市近海特种水产养殖基地在陆基围塘锯缘青蟹养殖中采用生态养殖技术,当年养殖的锯缘青蟹平均规格达265克以上,其中300克以上的锯缘青蟹占30%,该锯缘青蟹品质好,肉质鲜美,深受广大消费者所喜爱. 相似文献
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笔者于2002年3月到2005年5月,从对虾病害综合防治入手,结合本市中低盐度(4～15)虾池的特点,进行了斑节对虾与锯缘青蟹混养试验,取得较好的经济效益。现将其混养技术报告如下:一、材料与方法1.混养池条件一般对虾养殖池塘均可用于混养,面积5～20亩之间为宜,平均水深1.2米以上,底 相似文献
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为探索斑节对虾的生态健康养殖模式,优化养殖结构,于2011年2月开始进行斑节对虾池套养红鳍东方鲀、花蛤试验.在2口面积均为2.5 hm2的养虾池内,每口池塘放养75万尾斑节对虾虾苗,套养平均规格约85g/尾的大棚越冬红鳍东方鲀苗种1万尾和平均规格为260粒·kg-1的花蛤苗3500 kg.经过约10个月的养殖,共收获平均规格23.33尾·kg-1的斑节对虾24400 kg、3.2尾·kg-1的红鳍东方鲀5060 kg以及平均规格103粒·kg-1的花蛤17057 kg,产值205.99万元,利润121.81万元.斑节对虾的饲料系数为1.62,红鳍东方鲀为1.59.套养试验获得了良好的经济效益. 相似文献
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《水产科学》2021,(4)
以海水池塘陆基围隔试验法比较研究拟穴青蟹、斑节对虾、缢蛏三元混养模式,以拟穴青蟹、斑节对虾为基础,作为对照组(CS),混以5个不同搭配比例的缢蛏,即5个处理组(CSR1、CSR2、CSR3、CSR4和CSR5),对各混养模式的养殖效果、氮磷收支及利用率等方面进行单因素方差分析和多重比较。试验结果显示,各混养模式下饲料是氮、磷主要输入方式,分别占氮、磷总输入的84.02%～86.31%与98.08%～98.83%,底泥沉积是氮、磷主要输出方式,分别占氮、磷总支出的44.21%～56.40%与50.38%～60.96%;不同混养模式下,养殖生物在规格、成活率、特定生长率、产量以及产值方面均存在差异,采用CSR3和CSR4混养模式可取得较高养殖效益;氮、磷利用率方面,各处理组氮利用率为12.35%～32.66%,且CSR5CSR3、CSR4CSR1、CSR2CS,差异显著(P0.05);磷利用率为9.38%～23.10%,CSR3、CSR4、CSR5CS、CSR1、CSR2,差异显著(P0.05)。试验结果表明在虾、蟹混养系统中加入适量密度缢蛏,可显著提高养殖系统养殖效益与氮、磷利用率。综上所述,结合养殖投入、养殖效益与氮、磷利用率等方面数据,CSR3处理组密度搭配最为合理,即在本试验条件下,青蟹、斑节对虾、缢蛏最优搭配为拟穴青蟹35只/25 m~2、斑节对虾300尾/25 m~2、缢蛏1000个/25 m~2。 相似文献
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关于锯缘青蟹Scylla serrara(Forskal)苗种中间培育(Intermediate Rearing)技术的探讨 总被引：1，自引：2，他引：1
利用670m2的方形土池在水温31.6～28.2℃;海水比重1.021从Ⅰ期锯缘青蟹仔蟹3万尾经过17d的培育共培育出Ⅴ～Ⅵ期幼蟹2.4548万尾,存活率为81.82%。另外在8口5×5×1.4(m)的水泥育苗池中在水温27.6～30.4℃;比重1.018～1.006的条件下从Ⅰ～Ⅱ期锯缘青蟹仔蟹26万尾经过5d的淡化培育共培育出Ⅲ～Ⅳ期仔蟹19.5266万尾,存活率为75.10%。 相似文献
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当前,天津地区的许多养殖场利用原有水体大规模养殖锯缘青蟹获得了成功,而自然海区锯缘青蟹的资源匿乏,苗种锐减,因此,解决锯缘青蟹人工育苗技术可以改变当地盐碱地池塘及半咸水池塘养殖品种单一的现状,使海水养殖得到可持续发展。一、亲蟹培育1.亲蟹来源亲蟹为天然海区已交配的雌蟹,可以通过轻压腹脐上方愈合处进行鉴别,如果贮精囊内有黄豆粒大的乳白色精点,即为已交配的雌蟹。亲蟹肥满度好,肢体完整,无病害,活力强,个体大,平均体重为300g/只~500g/只。2.亲蟹栖息环境亲蟹池5.0m×3.0m×1.3m,用经过消毒处理的细沙铺入池底,厚度约为15cm,出… 相似文献
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Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
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下载免费PDF全文 The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna. 相似文献
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Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
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In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg. 相似文献
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Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
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Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
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Sandra García‐Garrido Ismael Hachero‐Cruzado Carlos Rosas Pedro Domingues 《Aquaculture Research》2013,44(11):1741-1751
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting. 相似文献
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There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future. 相似文献
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Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load 下载免费PDF全文
下载免费PDF全文 Franz Lahnsteiner 《Aquaculture Research》2017,48(7):3901-3909
This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos. 相似文献
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T. Citarasu K. Venkatramalingam M. Micheal Babu R. Raja Jeya Sekar M. Petermarian 《Aquaculture International》2003,11(6):581-595
The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could
lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment
in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 103 to 3.76 × 105 cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load
in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 105 cfu/g).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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William King V David L. Berlinsky Craig V. Sullivan 《Fish physiology and biochemistry》1995,14(6):489-500
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass. 相似文献