Cd2+、Hg2+、Pb2+抑制罗非鱼EOG反应的研究

将不同浓度Ｃｄ２＋、Ｈｇ２＋、Ｐｂ２＋液分别灌注罗非鱼嗅觉器官,研究其对ＥＯＧ反应的影响。结果表明,这３种离子对ＥＯＧ反应均呈抑制效应,抑制作用的大小与金属离子的种类及浓度有关,Ｃｄ２＋、Ｈｇ２＋、Ｐｂ２＋有效ＩＣ５０分别为３３．９１、６７．７３、１９１．４４μｇ／Ｌ;毒性顺序为：Ｃｄ２＋＞Ｈｇ２＋＞Ｐｂ２＋。     

重金属离子对凡纳滨对虾的致病机理研究

研究了重金属离子Cd2+、Pb2+、Cr3+对凡纳滨对虾血清SOD、CAT活性的影响.结果表明,低、中等浓度的Cd2+、Pb2+、Cr3+均对凡纳滨对虾血清SOD活性表现为较强的诱导作用.在一定的时间和较高浓度下,Cd2+、Pb2+、Cr3+均对凡纳滨对虾血清SOD、CAT活性表现出显著抑制作用,具有一定的时间、剂量效应关系.在较低的Cd2+、Pb2+、Cr3+浓度下,SOD、CAT活性明显高于对照,且随着各处理浓度的增加和时间的延长(72 h),Cd2+、Pb2+、Cr3+对血清SOD、CAT活性表现出更加明显的抑制作用,即在低剂量、短时间内会导致酶活性提高;而在高剂量或长时间作用下,对虾SOD、CAT活性表现为抑制作用,且表现出2种金属离子对血清SOD、CAT活性的抑制作用比单一的金属离子抑制作用更加显著,显示出Cd2+、Pb2+、Cr3+复合污染具有明显协同作用.金属离子的胁迫下使SOD、CAT的活性比例失调,使对虾的生理代谢紊乱,加速对虾的衰老和死亡.     

蒽对黑鲪超氧化物歧化酶活性的影响

采用毒性实验的方法，研究了蒽对黑Ｊｕｎ几种组织的超氧化物歧化酶活性的影响。结果表明：１．不同的组织其ＳＯＤ活性高低不同，按ＳＯＤ活性由高到低的顺序依次排列为：肝＞血清＞肾＞鳃＞肌肉；２．不同的组织，其ＳＯＤ活性对蒽的敏感性有所差异，按敏感性由大到小的顺序依次排列为：血清＞肝＞鳃＞肌肉＞肾。３．不同组织的ＳＯＤ活性在蒽胁迫下的变化规律不同。低浓度的蒽引起鳃、肾、肌肉组织的ＳＯＤ活性升高，随着蒽浓度的提高，ＳＯＤ活性又表现出抑制效应；而蒽对血清及肝组织的ＳＯＤ活性从低到高浓度下始终呈现出抑制作用。     

中草药对凡纳滨对虾生长、免疫功能的影响

以凡纳滨对虾（Litopenaeus vannamei）为实验对象，基础饵料中分别添加不同水平的中草药（0％、1．0％、2．0％）,结果表明，添加不同剂量的中草药能显著提高凡纳滨对虾的增重率和增长率，显著地降低对虾的饵料系数，对凡纳滨对虾的成活率有极显著提高．能极显著提高对虾血清中溶菌酶和SOD活性，能显著提高ACP活性，极显著提高对虾对溶藻弧菌的免疫保护率。     

不同家系的万氏对虾对对虾杆状病毒抗病力的差异

不同家系的万氏对虾对对虾杆状病毒抗病力的差异郑国兴（东海水产研究所，上海２０００９０）关键词对虾杆状病毒，万氏对虾，抗毒力，家系ＤＩＦＦＥＲＥＮＣＥＩＮＲＥＳＩＳＴＡＮＣＥＴＯＥＸＰＥＲＩＭＥＮＴＡＬＩＮＦＥＣＴＩＯＮＳＷＩＴＨＢＡＣＵＬＯＶＩＲＵＳ...     

中国对虾对Pb、Cr、Zn及其混合物的回避反应

利用“Ｙ”形回避槽,进行了中国对虾（ Ｐｅｎａｅｕｓ　ｃｈｉｎｅｎｓｉｓ） 对Ｐｂ 、Ｃｒ、Ｚｎ 及其混　合物的回避反应实验。计算得出中国对虾对Ｐｂ 、Ｃｒ、Ｚｎ 的５０ ％ 回避率浓度分别为１１ ．４、３３．２ 、和２３８．１ｍｇ／Ｌ。对虾对Ｐｂ － Ｃｒ 及Ｐｂ － Ｚｎ 混合液的回避反应呈相加作用,但当混合液浓度为０．５ 毒性单位Ｐｂ加０ ．５ 毒性单位Ｚｎ 时,回避反应呈协同作用。     

世界新对虾属的资源现状及养殖发展前景

世界新对虾属的资源现状及养殖发展前景ＳＴＡＴＵＳＯＦＭＥＴＡＰＥＮＡＥＵＳＲＥＳＯＵＲＣＥＳＡＮＤＰＥＲＳＰＥＣＴＩＶＥＳＯＮＣＵＬＴＵＲＥＤＥＶＥＬＯＰＭＥＮＴＩＮＴＨＥＷＯＲＬＤ纪成林（上海水产大学，２０００９０）ＪｉＣｈｅｎｇｌｉｎｇ（Ｓｈａｎ...     

对虾病毒病研究现状

对虾病毒病研究现状ＳＴＡＴＵＳＯＦＳＴＵＤＹＯＮＶＩＲＡＬＤＩＳＥＡＳＥＩＮＰＥＮＡＥＩＤＳＨＲＩＭＰ赵永泉（中国水产科学研究院南海水产研究所，广州５１０３００）ＺｈａｏＹｏｎｇｑｕａｎ（ＳｏｕｔｈＣｈｉｎａＳｅａＦｉｓｈｅｒｉｅｓＩｎｓｔｉｔｕｔｅ...     

我国对虾移植、增殖放流技术研究进展

我国对虾移植、增殖放流技术研究进展ＳＵＭＭＡＲＹＯＮＴＨＥＰＲＯＧＲＥＳＳＯＦＲＥＬＥＡＳＩＮＧＴＥＣＨＮＯＬＯＧＹＦＯＲＣＨＩＮＥＳＥＳＨＲＩＭＰＴＲＡＮＳＰＬＡＮＴＡＴＩＯＮＡＮＤＥＮＨＡＮＣＥＭＥＮＴＩＮＣＨＩＮＡ曾一本（中国水产科学研究院,北...     

细菌J-10对凡纳滨对虾非特异性免疫指标的影响

以凡纳滨对虾(Litopenaeus vannamei boone)为试验材料，将细菌J-10添加到饲料中投喂对虾，测定其对凡纳滨对虾血清酚氧化酶(PO)、抗菌活力(Ua)和溶菌活力(U1)、溶血素活性和血清中蛋白含量的影响。结果显示，试验组各项指标均优于对照组，用副溶血弧菌进行人工攻毒，免疫保护率达到40％。结果表明，细菌J-10可以增强凡纳滨对虾的非特异性免疫功能。     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

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.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

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.     

Involvement of gonadal steroids in final oocyte maturation of white perch (Morone americana) and white bass (M. chrysops): in vivo and in vitro studies

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.     

Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide

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.     

An overview of stress physiology of fish transport: changes in water quality as a function of transport duration

This study brings an integrated analysis about the relationship between water deterioration and its physiological consequences in live fish transport. The analysis was focused on the transport water and its deterioration, and physiological challenges imposed on the fish. Usual commercial handling procedures employed to mitigate fish stress during transport were discussed. Future topics of research for the establishment of safer fish transport protocols were proposed. Transport was classified into short (≤8 h) or long transport (>8 h). The main issue in short transports should be the prevention of water pH reduction, while in long transports it is the increase in ammonia. Plasma cortisol is the most employed marker for stress and is acutely elevated upon short episodes of transport, but remains elevated even in long‐transport events. Plasma glucose is perhaps a better marker for handling stress. Plasma lactate, pH, osmolality CO₂ and ions should be more often evaluated. Plasma Na⁺ and Cl^‐ are very useful markers of acidosis, due to their respective exchange for H⁺ and , for acid–base regulation. The establishment of species‐specific transport protocols should be preceded by such combined analyses of water and physiological parameters.     

Are hatchery‐reared abalone naïve of predators? Comparing the behaviours of wild and hatchery‐reared northern abalone,Haliotis kamtschatkana (Jonas, 1845)

Abalone populations have declined worldwide, generating interest in enhancement using hatchery‐reared individuals. In many cases, such restoration efforts have met with limited success due to high predator‐induced mortality rates. Furthermore, the mortality rates of outplanted hatchery abalone are often considerably higher than for wild individuals. This study uses northern abalone (Haliotis kamtschatkana) as a case study to determine whether hatchery‐reared abalone behave differently than their wild counterparts. In the field, outplanted hatchery‐reared abalone were significantly less responsive than wild abalone, in terms of number of abalone responding and intensity of response, to nearby movement and to physical contact with an inert probe. Also, when encountering a cue to which all abalone responded (a seastar predator), hatchery‐reared individuals remained subdued. Anti‐predator behavioural deficits in hatchery‐reared abalone were more pronounced in 4‐year‐old individuals than in 1‐year‐old individuals, suggesting an influence of either age or amount of time spent in the hatchery environment. These behavioural differences are expected to increase the vulnerability of hatchery‐reared abalone to predators, and are likely a major cause of their elevated predator‐induced mortality when outplanted.     

Effects of cadmium on the kinetics of calcium uptake in developing tilapia larvae, Oreochromis mossambicus

The toxic effects of Cd²⁺ on Ca²⁺ influx kinetics in developing tilapia (Oreochromis mossambicus) larvae were evaluated. Addition of 20 µg l^-1 of Cd²⁺ to the environment of 0 and 3 day-old larvae competitively inhibited the Ca²⁺ uptake within 4h resulting in a great increase in K_m values for Ca²⁺ influx (19.3 and 17.4 fold, respectively) as compared with their respective controls. Consequently, the actual Ca²⁺ influx of larvae in solutions of 0.2 mM Ca²⁺ are suppressed by 32–45%. Also, 3 day-old larvae were more sensitive to internally accumulated Cd²⁺ than 0 day-old larvae. Although the Ca²⁺ influx in 0 and 3 day-old larvae may be restored to the levels of their respective controls with 24h of being transferred to a 20 µg l^-1 Cd²⁺ solution, total body Ca²⁺ content was significantly reduced in 3 day-old larvae. Increased Ca²⁺ uptake efficiency ensures sufficient Ca²⁺ for normal growth. However, rapid increase in Ca²⁺ influx after hatching also leads to higher Cd²⁺ uptake. Exposure to Cd²⁺ will lead to a drop in body Ca²⁺ content resulting in retardation of larval growth. Therefore, we conclude that if Ca²⁺ uptake is interfered with at this critical stage of development, larvae will not be able to maintain normal levels of body Ca²⁺ and will show signs of Cd²⁺ poisoning.     

Migratory dynamics of stream-spawning longnose gar (Lepisosteus osseus)

Abstract– Literature evidence suggests that lake-dwelling longnose gar (Lepisosteus osseus) enter tributary streams to spawn, Until the present study, the dynamics of this breeding migration had never been investigated quantitatively. During the summers of 1991 and 1992, longnose gar were captured as they entered Weaubleau Creek, Missouri, a tributary of Harry S. Truman Reservoir. The in-stream spawning migration began in early April and ended in late May, and was positively correlated with stream flow and water level, and negatively correlated with water temperature. In-stream residence times ranged from 15 to 94 days, with males exhibiting longer residence times than females. Once in-stream, longnose gar travelled as far as 10 km upstream and occupied certain pools at greater relative frequencies. Although the reason for this preferential utilization is not completely understood, it may relate to pool depth and riffle proximity. Longnose gar disperse from the spawning stream great distances, with gar captured in Weaubleau Creek being recaptured up to 48 km away. This information should provide fisheries biologists the means to consider the reproductive ecology of this species in their conservation and management decisions.     

Nutritional regulation of hepatocyte fatty acid desaturation and polyunsaturated fatty acid composition in zebrafish (Danio rerio) and tilapia (Oreochromis niloticus)

The desaturation and elongation of [1-¹⁴C]18:3n-3 was investigated in hepatocytes of the tropical warm freshwater species, zebrafish (Danio rerio) and Nile tilapia (Oreochromis niloticus). The hepatocyte fatty acid desaturation/elongation pathway was assayed before and after the fish were fed two experimental diets, a control diet containing fish oil (FO) and a diet containing vegetable oil (VO; a blend of olive, linseed and high oleic acid sunflower oils) for 10 weeks. The VO diet was formulated to provide 1% each of 18:2n-6 and 18:3n-3, and so satisfy the possible EFA requirements of zebrafish and tilapia. At the end of the dietary trial, the lipid and fatty acid composition was determined in whole zebrafish, and liver, white muscle and brain of tilapia. Both zebrafish and tilapia expressed a hepatocyte fatty acid desaturation/elongation pattern consistent with them being freshwater and planktonivorous fish. The data also showed that hepatic fatty acid desaturation/elongation was nutritionally regulated with the activities being higher in fish fed the VO diet compared to fish fed the FO diet. In zebrafish, the main effect of the VO diet was increased fatty acid Δ6 desaturase activity resulting in the production of significantly more 18:4n-3 compared to fish fed the FO diet. In tilapia, all activities in the pathway were greater in fish fed the VO diet resulting in increased amounts of all fatty acids in the pathway, but primarily eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3). However, the fatty acid compositional data indicated that despite increased activity, desaturation of 18:3n-3 was insufficient to maintain tissue proportions of EPA and DHA in fish fed the VO diet at the same level as in fish fed the FO diet. Practically, these results indicate that manipulation of tilapia diets in commercial culture in response to the declining global fish oil market would have important consequences for fish fatty acid composition and the health of consumers. Scientifically, zebrafish and tilapia, both the subject of active genome mapping projects, could be useful models for studies of lipid and fatty acid metabolism at a molecular biological and genetic level. This revised version was published online in August 2006 with corrections to the Cover Date.     

Production of diatom–bacteria biofilm isolated from Seriola lalandi cultures for aquaculture application

Controlled incorporation of selected microalgae and bacteria in aquaculture systems can be beneficial because they can act as microbiological control. That is why the characteristics of biofilm generated naturally in Seriola lalandi culture cages were analysed, their potential benefit to the growth of larvae was studied, and their controlled use for improving the larval viability and as a vector to improve incorporation of previously studied probiotic bacteria was tested. According to biodiversity results, these biofilms are composed of a diatom–bacteria mix showing a decrease in biodiversity in laboratory culture conditions being dominated by Navicula phyllepta and bacteria of the family Rhodobacteraceae. This can be produced on mesh substrates incorporated in bioreactors with rapid growth rate and adhesiveness. Preliminary results from the addition of substrates with this specific biofilm in larvae culture systems showed that it is consumed by the larvae without negative effects, while positive effects on the viability of larvae in combination with probiotics were observed. Considering preliminary results, the addition of these specific substrates with diatom–bacteria biofilms could be a good improvement for aquaculture systems and together with the use of probiotics can contribute to maintaining a stable and controlled system improving the viability of the larval fish culture in its early stages.