中国对虾（Penaeus orientalis Kishinouye）的几种必需脂肪酸营养价值的比较研究

用四种试验饵料，其中分别含有１％高纯度的ω－３及ω－６不饱和脂肪酸（亚油酸Ｃ１８∶２ω６、亚麻酸Ｃ１８∶３ω３、花生四烯酸Ｃ２０∶４ω６、二十二碳六烯酸Ｃ２２∶６ω，ＤＨＡ）以及一种对照饵料含有５％棕榈酸Ｃ１６∶０和油酸Ｃ１８∶１ω９混合物对中国对虾（ＰｅｎａｅｕｓｏｒｉｅｎｔａｌｉｓＫｉｓｈｉｎｏｕｙｅ）幼虾进行了为期３２天的投喂试验，从成活率、蜕皮次数及增重等实验结果可见二十二碳六烯酸（ＤＨＡ）对中国对虾幼虾具有最高的营养价值。同时，对海捕和人工养殖的中国对虾的脂肪酸组成进行了比较，两者都含有大量的ω－３系列的高度不饱和脂肪酸；但是与海捕虾相比较，人工养殖对虾的ＤＨＡ含量较低，而亚油酸含量较高。上列结果表明在对虾饵料中补充富含ＤＨＡ的脂肪源将有效地促进对虾增产。     

野生及人工养殖的中国对虾（Penaeus Chinensis）的脂肪酸组成的分析及比较研究

通过对野生及人工养殖的中国对虾的肌肉、肝胰脏、性腺及卵的脂肪酸的分析比较，结果显示野生及人工养殖的中国对虾都含有大量的ω－３系列高度不饱和脂肪酸，这与其它海洋甲壳类的脂肪酸组成相类似；与野生的中国对虾相比较，人工养殖对虾的各组织及卵含有较高比例的亚油酸及较低比例的二十二碳六烯酸（ＤＨＡ）。野生与人工养殖的中国对虾在脂肪酸组成上的这一差异，是由于它们的生态环境及所摄食物的不同所造成的。从我们先前的实验证明ω－３系列和ω－６系列长链高度不饱和脂肪酸是中国对虾的必需脂肪酸，其中尤以ＤＨＡ最为重要，对于幼虾的生长及亲虾的成熟都是必需的。可见在人工养殖中国对虾的配饵中添加富含ＤＨＡ的脂肪源将是提高人工养殖对虾产量和质量的一个重要途径。     

长毛对虾仔虾对不饱和脂肪酸需求量的初步研究

用正交法对不饱和脂肪酸进行６因素２水平的饲料含量设计，并在对虾营养试验系统中进行饲养实验。结果表明；长毛对虾仔虾的生长率，存活率受不２饱和脂肪酸种类与含量的影响。在本实验条件下，长毛对虾仔虾期Ｃ１６：ｎ，Ｃ１８：ｎ，Ｃ１８；２ｎ，Ｃ１８；３ｎ，Ｃ２０：１－５ｎ和Ｃ２２－２４的最适宜含量分别上饲料的０．２４％，１．４０％，１．８５％，０．４３％，０．７６％和２．２５％。     

三种海胆性腺总脂的脂肪酸组成的研究

本文采用了ＦＦＡＰ石英毛细和气相色谱柱，对光棘球海胆，虾夷马粪海胆及海刺猬的性腺中总脂的脂肪酸组成进行了研究。结果表明这几种海胆含有四十种以上的脂肪酸，分布十分相似。主要的ＨＵＦＡ为１８：４ｎ－３（３．２％－７．４），２０：４ｎ－６（６．４％－１６．７％）及２０：５ｎ－３（６．６％－１２．１％），并含有非常罕见的ｎ－５及ｎ－７烯酸。     

中国对虾（Penaeuschinensis）脂肪酸转化能力的研究

用脂肪酸含量不同的饲料饲喂中国对虾，结果表明，对虾具有亚油酸转化为二十碳四烯酸、将亚麻酸转化为二十碳五烯酸和二十二碳六烯酸的能力，但转化率低。     

野生及人工养殖的中国对虾的脂肪酸组成的分析及比较研究

通过对野生及人工养殖的中国对虾的肌肉、肝胰脏、性腺及卵的脂肪酸的分析比较，结果显示野生及人工养殖的中国对虾都含有大量的ω－３系列高度不饱和脂肪酸，这与其它海洋甲壳类的脂肪酸组成相类似；与野生的中国对虾相比较，人工养殖对虾的各组织及卵含有较高比例的亚油酸及较低比例的二十二碳六烯酸（ＤＨＡ）。野与人工养殖的中国对虾在脂肪酸组成上的这一差异，是由于它们的生态环境及所摄食物的不同所造成的。从我们先前的实验     

饲料中不饱和脂肪酸对斑节对虾幼虾存活、蜕皮和生长的影响

在基础饲料中添加四种含不同脂肪酸的脂肪源组成四种试验饲料，对斑节对虾幼虾进行４５天的喂养试验。结果表明，饲料中含有高度不饱和脂肪酸（ＨＵＦＡ），能促进幼虾的生长和提高幼虾的成活率。幼虾摄食含有不同脂肪酸的饲料，虽然虾体内脂肪含量接近，但虾体脂肪酸含量差异显著。斑节对虾幼虾对１８碳以下的脂肪酸转化能力有限。在斑节对虾幼虾的养殖饲料中直接添加含有ＨＵＦＡ的脂肪源是必要的。     

ω—3及ω—6不饱和脂肪酸对中国对虾幼虾存活,蜕皮和生长的影响

用高纯度单一ω-3和ω-6系列脂肪酸、亚油酸、亚麻酸、花生四烯酸以及二十二碳六烯酸,分别以饵料1％的含量添加到含脂类4％棕榈酸和油酸的基础饵料中,组成四种试验饵料。对照饵料的脂类组成为5％的棕榈酸和油酸。对中国对虾幼虾进行32天的投喂试验,测定ω-3和ω-6系列不饱和脂肪酸对幼虾存活、蜕皮和生长的影响。结果表明,投喂不含ω-3和ω-6系列脂肪酸的对照饵料,幼虾生长几乎停止,存活率极低。添加1％的亚油酸或亚麻酸或花生四烯酸,效果较好;添加1％的二十二碳六烯酸,效果最佳。说明ω-3和ω-6系列不饱和脂肪酸对中国对虾幼虾的存活和正常生长是必需的。     

地下卤水养殖中国对虾试验报告

地下卤水经盐度及主要离子含量的调节后，用于养地虾，能防止病毒性虾病的发生。用地睛卤水养殖中国对虾２年试验结果表明：０．６ｃｍ的虾苗经２５天暂养，体长达３．０ｃｍ，成活率为６３－６６．７％，再经４个月养殖，体长增至１１．２－１３．２ｃｍ，每亩产量达到３９．７－９２．５ｋｇ     

饲料中不同脂肪酸搭配对仿刺参幼参生长和体组分的影响

在水温13．0～23．0℃下，将平均质量1.45g的仿刺参Apostichopus japonicus幼参放养在容量50L（45cm×31cm×30cm）的水槽中，投喂以鱼粉、虾糠和玉米蛋白为蛋白源，添加马尾藻粉、海泥、贝壳粉和黄原胶等粗蛋白12．70％和粗脂肪5．48％的饲料。在饲料中含有不同比例的亚油酸（LA）、α-亚麻酸（LNA）、二十二碳六烯酸（22：6n-3）（DHA）和二十碳五烯酸（20：5n-3）（EPA），以橄榄油平衡脂肪含量，以贝壳粉平衡其他成分，配制成LA和LNA的比例分别为20：0（S1）；20：1（S2）；1：2（S3）和2：1（S4）；LA、LNA、DHA和EPA的比例分别为6：1：5：0（S5）；10：1：30：5（S6）和10：5：6：1（S7）的膏状饲料。80d的饲养表明，幼参摄食只添加橄榄油（S1）、添加橄榄油和亚油酸（S2）的饲料时生长最慢，显著低于其他各组的幼参（P〈0．05）；摄食只添加亚麻酸（S3）或亚油酸和亚麻酸（S4）的饲料时，生长较慢，二者差异不显著（P〉0．05），但均显著低于摄食添加DHA（S5）和EPA＋DHA（S6）的幼参（P〈0．05）；摄食添加上述4种脂肪酸（S7）饲料时，生长最快，即LA，LNA，DHA和EPA的比例为10：5：6：1时，体壁最厚，肠道中淀粉酶和蛋白酶的有效活力最高，对饲料脂肪和蛋白质的消化率显著高于其他各组（P〈0．05）。摄食实验饲料的仿刺参体内蛋白＋脂肪十灰分的含量之和（平均85．79％）远大于初始刺参（79．70％）的相应之和，由高至低依次为：S2（90．57％）〉S1（87．97％）〉S3（85．78％）〉S4（85．29％）〉S7（84．19％）〉S5（83．79％）〉S6（82．97％）。仿刺参摄食后体内18碳脂肪酸含量呈负增长，而体内EPA的含量均呈正增长，且恒定变化在4．36％～6．83％之间，表明饲料中的18碳脂肪酸能转化为仿刺参体内的EPA。添加了4种脂肪酸的S4、S5、S6和S7组幼参肠过氧化氢?     

Effects of nauplial density, product concentration and product dosage on the survival of the nauplii and EFA incorporation during Artemia enrichment with liposomes

In order to determine an optimal enrichment protocol with krill phospholipid liposomes, three different experiments were carried out to evaluate the effects of nauplial density, the concentration of liposome, and the number of doses delivered to the nauplii on the survival and the essential fatty acid (EFA) bioencapsulation in Artemia nauplii. No survival differences were found between the different liposome treatments and the control nauplii enriched with a commercial emulsion. This result confirms that previously described mortalities during Artemia enrichment with liposomes can be minimized and controlled. On the other hand, the EFA incorporation obtained from the three experiments indicates that maximal bioencapsulation is achieved when incubations are carried out under nauplial densities of 300 nauplii ml^− 1, where liposomes are dispensed in a single dose at the beginning of the incubation yielding a concentration of 0.5 g l^− 1. These findings complete those obtained in two preliminary studies, and propose a well defined enrichment protocol with krill liposomes as an alternative complementary method to improve the nutritional value of the Artemia nauplii used as food for marine fish larvae.     

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.