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β-1,3-葡聚糖及其羧甲基衍生物对海湾扇贝免疫功能的影响 总被引：3，自引：0，他引：3
2003年3月和2004年4月，新疆某养殖场和西安灞桥区某养殖场的白斑狗鱼（Esox lucius Linnaeus）相继爆发“败血症”。从具有明显症状的濒死病鱼体表病灶和内脏组织分离得到12株优势菌株，经人工感染试验表明：其中10株分离菌为致病菌。对分离菌株进行形态、培养特征、生理生化试验鉴定，认为该病原菌为杀鲑气单胞菌史氏亚种（Aeromonas salmonida subsp．smith）。血清学试验表明各分离菌株具有相同的保护性抗原。组织病理学研究表明：患病狗鱼病灶肌纤维明显肿胀断裂，肌纤维束之间出现间隙；肝胰组织严重坏死，细胞核溶解消失，细胞浆崩解；肾小管绝大部分均已坏死，细胞破裂，胞浆呈红色团块状流失于管腔。脾脏细胞大量坏死，髓质内含铁血黄素沉积。代表菌株EL0304-1药敏试验结果为：对供试24种抗菌药物中的磺胺二甲嘧啶钠、磺胺二甲嚯唑钠等不敏感；庆大霉素、卡那霉素等中度敏感；对氧氟沙星、培氟沙星、新霉素等高度敏感。 相似文献
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Balázs Kucska László Pál Tamás Müller Márk Bódis Ádám Bartos László Wágner Ferenc Husvéth & Mikós Bercsényi 《Aquaculture Research》2006,37(1):96-101
Fat content and fatty acid profile of two pike yearling groups grown on two different diets were compared. The groups originated from culture on artificial feed. One group (cultured pike fed first pellet then prey‐fish (PF)) was fed with natural food, live prey‐fish, while the other one (cultured pike fed exclusively pellet (PP)) by trout feed through a 3‐month experimental period. Growth of pike was lower with PP than with PF. The trout feed resulted in an increase of the fat content of fillet and the formation of abdominal fat depots. Feeding of natural food decreased the fat content. The proportion of the saturated fatty acids in fillet was higher in the (PF) group. The n‐6 fatty acids (arachidonic C20:4n‐6 and docosatetraenic C22:4n‐6 acids) were lowest in PP‐fed pike. Regarding total n‐3 fatty acids ratio there was no significant difference between the groups, but the level of α‐linolenic (C:18:3n‐3) acid showed significant difference among groups. 相似文献
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Abstract – A total of 40 (20 age-3 + 20 age-4) radio-tagged hatchery-reared brown trout ( Salmo trutta L.) and 40 wild radio-tagged northern pike ( Esox lucius L.) were released into a regulated river. Age-3 brown trout were predicted and observed to be highly vulnerable to predation by pike (50% mortality), whereas age-4 brown trout were predicted and observed to enjoy an almost absolute size refuge from predation (5% mortality). Almost half of the fish from both age groups similarly emigrated and survived from the river within 3 days of the release. However, there was a considerable difference in survival between age groups for fish that remained in the river for a longer period. Of these, all except one age-3 brown trout were eaten by pike, whereas all but one age-4 fish survived predation. 相似文献
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采用PHA和秋水仙素胸腔体内注射法,以头肾组织为材料,低渗-空气干燥法制片,对取自新疆额尔齐斯河流域白斑狗鱼的染色体核型进行了分析。经对5尾白斑狗鱼的45个中期分裂相进行显微分析和测量,结果显示:白斑狗鱼的25对染色体均为端部着丝粒染色体,其核型公式为2n=50 t,NF=50。白斑狗鱼染色体大小的绝对值为0.96~1.36μm,平均长度为1.20μm。25对染色体相对长度大小依次递减,大小差异较显著,平均值为5.68。目前,对新疆额尔齐斯白斑狗鱼的染色体组型研究尚未见报道。 相似文献
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Abstract – Threespine stickleback ( Gasterosteus aculeatus ) samples from Prator Lake in southcentral Alaska consist of the relatively rare form of weakly armoured individuals with few lateral plates and no pelvic spines. Prator Lake has been sampled for threespine stickleback since 1983. Exotic northern pike ( Esox lucius ) were first observed in this lake in 1996. The appearance of pike corresponds with a dramatic decrease in stickleback numbers and apparent local extinction. The stickleback population may have been vulnerable to an exotic predator because Prator Lake lacks native piscivorous fishes, and this population had extreme armour reduction. 相似文献
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养殖密度和温度对白斑狗鱼在设施养殖中生长的影响 总被引：11，自引：0，他引：11
研究了养殖密度和温度对白斑狗鱼稚鱼在设施养殖中生长的影响。经过30d的养殖试验发现养殖密度和温度对白斑狗鱼稚鱼在设施养殖中的摄食和生长都有显著影响。日增重、特定增长率、生长效率、摄食效率随密度的增大而减小,净增重24ind·m-3和16ind·m-3密度组最高;随着温度的升高,日增重、特定增长率、生长效率均呈现先升高后下降的趋势,其中24℃组生长最快,摄食效率则随温度的升高而增大。特定生长率与密度之间存在显著直线回归关系,其回归方程为SGR=7.30-0.122SD(r2=0.9927);养殖温度和特定增长率之间存在显著二次函数关系,其回归方程为SGR=-0.047T2 2.169T-19.56(r2=0.8342),当温度为23.1℃时,白斑狗鱼的特定增长率最大为5.544,表明白斑狗鱼最适生长水温应在23～24℃。白斑狗鱼尽管是凶猛性鱼类,但只要控制好一定的养殖密度和水温,进行设施养殖是可行的。 相似文献
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Ine S. Pauwels Peter L.M. Goethals Johan Coeck Ans M. Mouton 《Ecology of Freshwater Fish》2014,23(3):373-382
Northern pike, Esox lucius, needs different habitats to survive and reproduce and thus depends on the availability and accessibility of these habitats. To efficiently manage pike, information is needed on its spatial and temporal patterns of migration. In this study, we investigated the occurrence of adult pike migration and which environmental variables influenced migration. From December 2010, we followed 15 pike for 1 year by use of radio telemetry in the River Yser, a typical lowland river characterised by anthropogenic impacts such as artificial embankments. Pike migrated most in February and March, which could indicate they frequented spawning habitat in this period. Four environmental variables significantly affected pike migration, ranging from the location where pike were observed (strongest effect), over water temperature and flow to diel water temperature change (weakest effect). The relation between migration and the location where pike were observed could demonstrate that pike preferred specific regions in the river. Increasing water temperature triggered migration for both sexes, and males started migrating at lower temperatures than females, which suggests that males start migrating earlier. This was the only substantial difference observed between male and female pike migration. The results suggest that migration was inhibited by high flow, as no migration was observed at high flow. River managers can use this information to efficiently manage their pike populations, for example, by removing or temporarily opening hydraulic structures like valves, weirs and sluices. This may facilitate access to suitable habitats at moments pike needs these habitats to fulfil its life cycle. 相似文献
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在水温22~26℃条件下,研究了在不同饥饿时间处理后再投喂对白斑狗鱼(Esox lucius)生长性能的影响,试验设置饥饿14、21、28、35、42 d组和正常投喂对照组,各组饥饿结束后恢复正常投饵,在投喂后以7 d为一个生长阶段,比较各处理组的增重率、特定生长率、摄食率、饲料系数,试验周期为56 d。结果显示,随着饥饿时间的延长,白斑狗鱼的总体重损失率呈逐渐升高的趋势,而各饥饿阶段体重损失率呈下降的趋势;各饥饿处理组恢复投喂后的增重率和特定生长率均显著高于对照组(P<0.05),且随饥饿时间的延长而逐渐升高,但在恢复投喂后的第35天,S14组(饥饿14 d组)与对照组无显著性差异(P>0.05);各饥饿处理组恢复投喂后的摄食率随饥饿时间的延长而显著性升高(P<0.05);饵料系数随饥饿时间的延长而逐渐下降,其中在第14天时,S42组(饥饿42 d组)的饵料系数显著高于其他饥饿处理组(P<0.05),与对照组无显著性差异(P>0.05)。在同一饥饿处理组,随着投喂时间的延长,增重率、特定生长率和摄食率均呈显著性下降的趋势(P<0.05),饵料系数呈升高的趋势,其中S14组在第35天时恢复到对照组水平。结果表明:摄食率升高和饵料系数下降是饥饿再投喂白斑狗鱼增重率显著上升的原因,且这种生长倾向随着恢复投喂时间的延长而不断减弱。 相似文献
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温度对白斑狗鱼胚胎发育的影响 总被引：2，自引：1，他引：1
研究了不同梯度的孵化温度对白斑狗鱼(Esox lucius)胚胎发育的影响,并对其孵化率和畸形率等指标进行了统计分析。结果显示:在各温度梯度组中,16℃温度组的孵化率和正常仔鱼孵出率均最高,分别为61.5%和59.75%,其次为14℃温度组,其孵化率和正常仔鱼孵出率分别为59.75%和56.25%;白斑狗鱼胚胎发育的适温范围为14~16℃;水温和发育时间呈显著负线性相关,其相关方程为:Y=-20.133X+469.8,R2=0.9678;在8~18℃范围,总积温为2130.19~2825.96℃.h。 相似文献