栉孔扇贝能量收支的研究

报道了在模拟自然条件下栉孔扇贝能量收支研究的实验结果。实验数据显示,在实验的温度范围内（８～１７．２℃）栉孔扇 贝的个体耗氧率和个体排氨率随壳长的增大和水浊的升高而增大,呈下相关关系。栉孔扇贝的个体大小是影响能量收支各组分比例的主要因素。随个体的增大,扇贝的呼吸能增大,而生长能减小。在能量收支方程中,呼吸能占的比例最大（４４．２％～５１．７）,其次是排粪能（３１．４％～３６．８％）,第三为生长能（     

不同生长时期中国对虾蛋白酶,脂肪酶活性变化的研究

本文对中国对虾生长各阶段的蛋白酶和脂肪酶活性变化进行了分析，探讨了蛋白质和脂肪的消化利用。结果表明，从中国对虾生长与消化酶活性的关系可将其分为两个生长阶段。第一阶段，体长在２．５５－１０．１１ｃｍ间（饲养时间为６月８日至８月２７日），在这一时期随着个体增大蛋白酶，脂肪酶活性不断升高。９月份对虾消化酶活性趋于下降，构成了在养殖后期消化功能趋于减弱的第二阶段。进入繁殖期的对虾与个体大小相似的生长期对虾     

不同温度下太平洋牡蛎三倍体和二倍体生物能量学比较

对一龄太平洋牡蛎三倍体和二倍体能量收支比较研究的结果表明，在５～３０℃下，二倍体摄入能量的３２％为粪能、３．６５％为排泄能、４１．６６％消耗于呼吸、２２．８１％用于生物生长；三倍体摄入能量的２３％为粪能、７．５４％为排泄能、４０．６５％的能量用于呼吸、２８．７８％为生长。经协方差检验，倍性和温度对牡蛎的生长能、同化能和排泄能影响显著，对代谢能和摄食能作用不明显。实验还表明，二倍体Ｋ２值平均３３．９     

不同生长时期中国对虾蛋白酶、脂肪酶活性变化的研究

本文对中国对虾生长各阶段的蛋白酶和脂肪酶活性变化进行了分析，探讨了蛋白质和脂肪的消化利用。结果表明，从中国对虾生长与消化酶活性的关系可将其分为两个生长阶段。第一阶段，体长在２．５５─１０．１１ｃｍ间（饲养时间为６月８日至８月２７日），在这一时期随着个体增大蛋白酶，脂肪酶活性不断升高。９月份对虾消化酶活性趋于下降，构成了在养殖后期消化功能趋于减弱的第二阶段。进入繁殖期的对虾与个体大小相似的生长期对虾相比较，不同组织的蛋白酶和脂肪酶活性差别情况不同，但总趋势是性腺发育的对虾蛋白酶、脂肪酶活性强于生长期对虾，海捕越冬亲虾蛋白酶、脂肪酶活性高于人工养殖越冬亲虾。     

不同饲养条件对中国对虾血清蛋白、血脂、血糖含量变化的初步研究

本文通过不同蛋白质含量饲料（蛋白质含量分别为３０％、４０％、５０％、６０％）及不同温度条件（１５±１℃、２５±１℃、２９±１℃）饲养中国对虾，测其血清蛋白、血脂、血糖含量的变化，以此血液指标结合生物学生长指标考察对虾的营养状态。结果表明，５０％蛋白质含量饲料饲养的中国对虾，血液指标和生长指标是一致的，都好于其它饲料组，２５±１℃条件下饲养的中国对虾，血液指标和生长指标一致好于其它水温组。     

pH值和Ca~（2＋）浓度对日本沼虾生长和能量收支的影响

本文报道了不同ｐＨ值（６．５、７．５和８．５）和不同Ｃａ２＋浓度（３８．８．６１．１和７８．８ｐｐｍ）对日本沼虾生长和能量收支的影响。实验结果表明，ｐＨ值对该虾的生长有一定的影响，Ｃａ２＋和ｐＨ值在影响其生长的过程中可能有一定的交互作用。ｐＨ值和Ｃａ２＋对该虾生长的影响主要是通过影响其能量摄入量实现的。本实验条件下，该虾摄入的能量平均有１５．８％用于生长，１．８％作为粪便排出体外，其余用于呼吸和排泄。     

虎纹蛙的养殖技术

１生态习性虎纹蛙属两栖纲、无尾目、蛙科、虎纹蛙属。其分布很广，遍布长江以南各省，属于国家二类保护动物。虎纹蛙属变温动物，其生长温度为２２～３０℃，气温在４℃以下或气温在３５以上时，易引起死亡。当气温低于１２℃时，即停食开始冬眠，春季气温上升到１６℃才结束冬眠。当气温高于３０℃以上时，其新陈代谢受到抑制。虎纹蛙虽能长期离水，但其皮肤要保持湿润，适度光照可加强其新陈代谢，促进生长和性腺发育。虎纹蛙对水质的要求较低，适宜ｐＨ值在６．８～７．８之间，另外，盐份太高（２０％ｏ以上）可导致脱水死亡。２人工繁…     

长吻的营养和饲料研究Ⅱ温度对摄食、生长及饲料转化效率的影响

在室内流水条件下测定不同温度（１５℃、２０℃、２５℃和３０℃）对长吻幼鱼摄食，生长及饲料转化效率的影响。结果表明：长吻摄食与生长的起始温度为１５℃；适宜温度区为２０—３０℃；最适温度为２５℃左右。水温为１０℃时，长吻　基本不摄食，水温为１５—２５℃时，长吻摄食率、生长率随永温升高而显著增加，２５℃和３０℃组间差异不大。饲料转化效率随水温上升明显提高，但水温升至３０℃时，饲料转化效率有下降的趋势。长吻幼鱼日投饵量可根据经验公式：Ｃ＝０．１４８Ｔ￣（１．６２６）Ｗ￣（－０．５２１）计算。     

美国青蛙脑膜炎病的诊断及治疗

１病原体该病病原体为脓毒性黄杆菌，大小为０．４微米×２微米，电镜可看到有荚膜样结构。能在普遍琼脂平板上生长，但发育缓慢，７２小时后形成圆形隆起、带黄色光泽、直径１毫米以上的菌落。温度５～３０℃时均能发育，生长适温为１５～２０℃，３７℃以上不发育，在含氯化钠０．１％～４％培养基上生长，含氯化钠０．５％～１．０％时生长良好，不含氯化钠的培养基不发育；pH值在６．５～１０．２均发育，最适pH值为７．８～８．３，对氯霉素、红霉素很敏感。２症状病蛙精神不振，行动迟缓，食欲减退，肛门红肿，眼球外突，双目失明，…     

盐度与温度对马氏珠母贝能量收支的初步研究

以亚心形扁藻为饵料,分别研究了盐度（15、20、25、30、35％o）、温度（10、15、20、25、30℃）对能量收支的影响。测定了马氏珠母贝的摄食能、生长能、呼吸能、排泄能、排粪能以及各组分占摄食能的比例。结果表明：（1）盐度梯度下,马氏珠母贝摄食能、生长能、呼吸能、排泄能及排粪能均有显著性差异（P〈o．05）;从占摄食能比例看出,盐度为30％。时的生长能、呼吸能、排泄能与其余梯度间存在显著性差异（P〈0．05）;（2）温度梯度下,贝的摄食能、生长能、呼吸能及排泄能与其他4个饵料浓度下的差异显著（P〈0．05）;从占摄食能的比例看出,温度为25℃时,生长能、排粪能与其余4温度组差异性显著（P〈O．05）。     

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.     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

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.