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水库网箱不同饵料养殖匙吻鲟试验 总被引：4，自引：0，他引：4
在水库网箱中进行了3种不同饵料养殖匙吻鲟试验,分别为不投饵但灯光诱饵、投喂鱼块和投配合饲料。初放鱼种平均体长16~18 cm,平均体重20~25g,放养密度为7.5~22.5尾/m2。经过近8个月的饲养,养殖成活率平均94.4%。结果显示,配合饲料组的生长最快,平均体重为1.26 kg;鱼块组的生长次之,平均体重0.78 kg;不投饵组平均体重仅0.42 kg。 相似文献
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以褐牙鲆(Paralichthys olivaceus)和大菱鲆(Scophthalmus maximus)为养殖对象,设计了2种新型的鲆鲽类网箱,即新型塑胶环保型单、双层网箱。通过褐牙鲆和大菱鲆网箱养殖实验来验证2种新型的网箱在实际生产中的可行性。结果显示,褐牙鲆传统木箱养殖组的商品鱼成活率为92.73%,单位面积产量为16.42 kg/m~2;塑胶单层网箱养殖组的成活率为96.37%,单位面积产量为17.42 kg/m~2。2个组的成活率、单位面积产量均存在显著差异(P0.05),单位面积产量同比增产6.10%。小规格大菱鲆传统网箱商品鱼成活率为92.50%,单位面积产量为8.09 kg/m~2;塑胶单层网箱组的商品鱼成活率为92.50%,单位面积产量为8.02 kg/m~2;塑胶双层网箱组的商品鱼成活率为92.00%,单位面积产量为10.53 kg/m~2,与传统网箱、单层塑胶网箱存在显著差异(P0.05),且同比增产分别为30.00%、31.00%。大规格大菱鲆单、双层塑胶环保型网箱养殖的成活率达到95.00%以上,单位面积产量均为14.52–16.32 kg/m~2;大规格大菱鲆双层网箱实验组平均尾重与单层网箱示范组差异显著(P0.05),单位养殖面积产量同比单层网箱示范组增产11.00%。研究表明,新型塑胶环保网箱养殖褐牙鲆效果良好。新型网箱相对于传统木制网箱除了具有节能环保、节约资源、操作便利的特点外,双层网箱养殖可提高有效利用面积,增加养殖效益。 相似文献
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长吻鮠网箱养殖试验 总被引：1，自引：0，他引：1
2005年网箱培育长吻鮠冬片鱼种,应用5 m×5 m×3.5 m的网箱,放养规格为3~4 cm/尾的长吻鮠夏花鱼种,放养密度56~790尾/m2,投喂粗蛋白为42%~46%的配合饲料,经7个月养殖,长吻鮠鱼种平均规格达165g/尾,成活率82.5%,单产9 kg/m2,饲料系数1.26,投入产出比1∶2.04;2006年网箱养殖长吻鮠商品鱼,应用5 m×5 m×4.5 m的网箱,放养规格为133 g/尾左右的长吻鮠冬片鱼种,放养密度32~50尾/m2,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/尾以上的长吻鮠商品鱼比例达86%以上,成活率82.6%~87.0%,饲料系数1.38,单产22.83~26.24 kg/m2,投入产出比1∶1.59。 相似文献
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2005年11月至2006年1月,分别在传统网箱和室内水泥池投放真蛸(Octopus vulgaris)野生苗种22062头,进行了养殖初步试验。主要结果为,55口传统网箱共放养10912头,平均体重233.6g,经过40d养殖,平均体重达660.9g,生长速度快,日增重率高达2.389%,养殖成活率62.8%,饵料系数为8.08。18口室内水泥池共放养11150头,平均体重220.5g,第一阶段经过33d养殖,平均体重达364.5g,生长速度不如传统网箱,日增重率1.402%,养殖成活率70.9%,饵料系数为6.04;第二阶段进入越冬期,生长更慢,经过53d养殖,平均体重达489.5g,日增重率只有0.552%,死亡较严重,养殖成活率仅44.3%,饵料系数为8.97。传统网箱养殖经济效益高于室内水泥池,投入产出比前者为11.210,后者为11.105。此外,还对影响真蛸生长和成活的各种因素、互残和自残行为等方面内容进行了分析探讨。 相似文献
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花(鱼骨)网箱养殖试验 总被引：10，自引：0，他引：10
采用人工配合饲料进行网箱养殖花鱼骨商品鱼的试验结果表明: 在水库利用 5m×5m×2. 5m的网箱, 放养规格为 56~60尾 /500g的花鱼骨冬片鱼种, 放养密度在 500~600尾 /m2, 经分养后养殖密度在 80尾/m2左右, 投喂含粗蛋白 40% ~42%的膨化沉性配合饲料, 经一周年养殖, 花鱼骨平均规格 213. 2g/尾, 平均成活率 86. 8%, 平均单产 16. 2kg/m2, 平均饲料系数 1. 34, 单位平均净收入为 226. 8元 /m2。 相似文献
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2010年,利用优质涌泉水资源,网箱培育达氏鳇鱼种32000尾,经过180d养殖,30g的鱼种长到2320g,平均日增长12.7g,总增重71942.9kg,总利润218.2万元,投入产出比1：4.7,饲料系数0.82,成活率98.2%。 相似文献
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在水库利用网箱培育脆肉皖所需的大规格鱼种,放养规格150-200g,平均密度3.75kg/m3,收获规格680g,养殖成活率92%,平均单产9.35kg/m3,平均饲料系数为1.79. 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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Growth hormone (GH) and reproduction: a review 总被引：5，自引：0，他引：5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations. 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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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
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Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide 总被引：1，自引：0，他引：1
Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response. 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