美洲帘蛤软体部营养成分分析及评价

美洲帘蛤Mercenariamercenaria(Linnaeus,1758)又称硬壳蛤、北方帘蛤或小圆蛤,原产地分布在美国佛罗里达州Cawrence湾,墨西哥湾,加利福尼亚Hamboldt湾到英格兰海域,与我国的文蛤(Meretrixmeretrix)同属帘蛤科,是一种生长快,适应能力强,适温、适盐范围广,经济价值高的大型双壳贝类[1,2]。目前生产性人工育苗已成功[3],2000年山东省海洋水产研究所由美国引入种贝,2001和2002年连续两年成功地进行了工厂化育苗,滩涂养殖正在逐步走向规模化。本文对美洲帘蛤软体部做了比较全面的营养成分测定分析,并与贻贝等多种双壳贝类进行了比较[4],旨在为…     

硬壳蛤与长毛对虾土池混养技术

<正>硬壳蛤(Mercenaria mercenaria Linnaeus)是我国近年来从美国引进的双壳贝类,隶属瓣鳃纲、真瓣鳃目、帘蛤科,又称小圆蛤、北方帘蛤或美洲帘蛤。它个体大、肉质鲜美、营养丰富。硬壳蛤为广温、广盐性贝类,能在沙底、沙泥底、泥底和海岸床等多种底     

尖吻鲈幼鱼耗氧率的研究

在不同水温条件下对两种规格尖吻鲈幼鱼的耗氧率进行测定。结果表明:(1)水温和规格对耗氧率有极显著的影响,小规格的明显高于大规格的,分别为0.1028±0.0251mg·g-1·h-1和0.0879±0.0215mg·g-1·h-1;(2)尖吻鲈幼鱼夜间的耗氧率比白天明显要高,分别为0.1109±0.0187mg·g-1·h-1和0.0799±±0.0186mg·g-1·h-1。     

美洲帘蛤池塘养殖试验

美洲帘蛤隶属于软体动物门、瓣鳃纲、帘蛤目、帘蛤科,又称硬壳蛤、北方帘蛤或小圆蛤,原产于美国东海岸,与我国的文蛤同属帘蛤科,属广温、广盐性底栖贝类,对环境耐性强,不仅能在砂底质而且能在泥底质中较好的生长,有较强的耐受低溶解氧能力,     

中华绒螯蟹雄性生殖系统生化组成及精子代谢

通过对中华绒螯蟹肝胰腺及生殖系统各组织生化成分和乳酸脱氢酶(LDH)活性的测定发现:总碳水化合物的含量以副性腺及输精管内容物(含精荚和精浆)较高,为33.456mg·g-1湿重和21.537mg·g-1湿重,肝胰腺、精荚及精巢的含量较低;碳水化合物中的糖原和葡萄糖含量分别以输精管内容物和肝胰腺最高,分别为0.385mg·g-1湿重和5.866mg·g-1湿重,精巢和肝胰腺中的糖原含量太低而无法检测到,精荚葡萄糖含量最低;蛋白质含量以肝胰腺最高,其余各部分含量显著低于肝胰腺;脂类含量以精巢和肝胰腺最高,其中的甘油三酯仅存于肝胰腺和精巢,且肝胰腺含量显著高于精巢。乳酸脱氢酶活性以贮精囊最高,精荚仅为中等,这可能与精荚壁的通透性有关,而精浆和肝胰腺显著低于其它组织。结果表明,中华绒螯蟹能量代谢主要物质是脂类和蛋白质;精子代谢的能量物质为碳水化合物,并由精浆提供,而其代谢的方式以厌氧代谢为主。     

维生素C、E对中华绒螯蟹生殖性能的影响

通过对河蟹雌性亲体投喂不添加或添加VC、VE的4组实验饲料,并以新鲜河蚌为对照,进行198d饲养试验,以雌蟹性腺系数、产卵力、孵化率以及各组织中SOD活性、MDA含量等指标作为判据,研究了VC、VE对雌蟹生殖性能的影响。结果表明,1(投喂添加0.5mg·(100g)-1VC饲料组)、2(投喂添加0.022mg·(100g)-1VE饲料组)和3(投喂添加0.5mg·(100g)-1VC饲料和0.022mg·(100g)-1VE饲料组)3个组雌蟹的产卵力分别为3620个卵细胞·g-1体重、3540个卵细胞·g-1体重、3710个卵细胞·g-1体重,孵化率分别是83.03%、84.06%、86.27%,均极显著高于4组(投喂未添加维生素饲料组)雌蟹的产卵力(2490个卵细胞·g-1体重)和孵化率(29.28%)(P<0.01),也显著高于5组(饲喂河蚌)雌蟹的产卵力(3010个卵细胞·g-1体重)和孵化率(71.12%)(P<0.05)。雌蟹卵巢中SOD活性,1、2和3组则比4组和5组显著低(P<0.05),分别为56.35Nu·mL-1、53.61Nu·mL-1和39.87Nu·mL-1,相应地,MDA含量分别为6.03nmol·mL-1、5.65nmol·mL-1和5.57nmol·mL-1;4组雌蟹,虽然其卵巢中SOD活性较高,达79.25Nu·mL-1,但因饲料中缺乏抗氧化性的VC、VE,引发卵子脂质过氧化,MDA含量显著增加(P<0.05),为23.18nmol·mL-1,导致卵质低下,从而影响了卵子孵化。综上所述,雌蟹饲料中添加适量的VC     

北太平洋柔鱼渔场浮游动物数量分布及与渔场的关系

根据2001年6-7月在北太平洋152°E～171°W、39°～42°N水域生态环境和资源综合调查资料,分析结果表明调查水域浮游动物总生物量均值为92.12mg·m-3(0.81～1035.68 mg·m-3),其中中部(160°～180°E、39°～42°N)及西经水域(170°～178°W、40°～41°N)为113.51mg·m-3,西部水域(152°～157°E、41°～43°N)为22.89mg·m-3;桡足类丰度居首(42.11%),其次为海樽类(30.91%);伪细真哲水蚤(Eucalanus pseudattenuatus)、太平洋哲水蚤(Calanus pacifica)和软拟海樽(Dolioletta gegenbauri)为主要优势种.甲壳类的分布与柔鱼中心渔场存在较好的对应关系,中心渔场位于浮游动物总生物量高密集区(250～500mg·m-3)和甲壳类的最高丰度区(50～100 ind·m-3)内或边缘区;头足类幼体分布于磷虾类和端足类的高丰度区(10～25ind·m-3)内或边缘水域.     

4种帘蛤目软体动物的营养成分分析与营养价值评价

测定了美洲帘蛤、四角蛤蜊、杂色蛤、文蛤的常规营养成分和各种氨基酸的含量，并对其营养价值进行综合评定。结果表明：4种帘蛤目软体动物的粗蛋白质含量均在44．35％以上，必需氨基酸与非必需氨基酸的含量比值大于1．00。谷氨酸、天冬氨酸、赖氨酸的含量最高。同时，4种风味氨基酸（天冬氨酸、谷氨酸、丙氨酸、甘氨酸）占氨基酸总含量的38．96％～39．47％。氨基酸计分（AAS）和化学评分（CS）显示，赖氨酸含量高于鸡蛋蛋白水平标准，可弥补谷类食物的不足。必需氨基酸指数（EAAI）则分别为73．45—79．48，具有非常高的营养价值。从鲜味氨基酸的比例和氨基酸组成来看，4种帘蛤目软体动物不仅味道鲜美，而且营养丰富，具有非常广阔的市场前景。     

硬壳蛤虾池生态养殖技术

<正>硬壳蛤又称小圆蛤、北方帘蛤、美洲帘蛤,是美国大西洋沿岸浅海和滩涂主要的经济双壳贝类之一,其肉质细嫩,味道鲜美,营养丰富,富含蛋白质,其贝壳具有很高的工艺价值和药物价值,同时硬壳蛤还具有生长速度快、适应性强等特点。为了进一步优化我市养殖品种结构,提高养殖经济效益,丰富老百姓的菜篮子,2012年7月~2013年8月,     

贝类养殖技术之五:美洲帘蛤国内围塘养殖技术

美洲帘蛤又称美国硬壳蛤,原分布于美国东海岸,是美国大西洋沿岸浅海和滩涂主要的经济双壳贝类之一,属广温、广盐性底栖贝类,对环境耐性强,不仅能在砂底质沿海生长,而且在泥底质中也能够获得较好的生长,特别适合泥砂质滩涂,比其他养殖贝类(如文蛤、青蛤)具更强的耐低溶解氧能力.我国的纬度与美洲帘蛤自然分布的地理纬度相同,自然条件能满足其生长需要,故可在我国广泛开展增养殖.近年来,浙江省玉环县连续引进美洲帘蛤试养,积累了不少养殖经验.     

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.     

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.     

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.