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We evaluated the ability of juvenile Amur sturgeon (Acipenser schrenckii) to osmoregulate and grow in saltwater. Hatchery-reared juveniles (mean weight 106.8 g, 5-month old) were transferred from freshwater to 10, 20, and 25 salinity saltwater over a period of 20 d. We measured the growth, serum osmolality, ion concentrations, and Na+/K+-ATPase activity. In addition, we prepared samples of gill tissue to quantify morphological changes in gill ultrastructure. Rearing in up to 25 saltwater for 30 d had no significant effect on growth. Similarly, serum osmolality and ion concentrations were similar to levels reported in other teleosts following acclimation to saltwater. Serum osmolality and Na+, Cl- concentrations increased significantly with the initial increase in salinity. Afterwards, levels tended to stabilize and then decrease. Serum K+ levels did not change during acclimation to saltwater. Gill Na+/K+-ATPase activity increased initially as salinity was increased. However, the activity later decreased and, finally stabilized at 3.7±0.1 μmol Pi/mg·prot·h in 25 saltwater (1.6 times higher than the level in those in freshwater). In fish that were held only in freshwater, the chloride cells were located in the interlamellar regions of the filament and at the base of the lamella. Following acclimation to 25 saltwater for 30 d, the number and size of chloride cells increased significantly. Our results suggest that juvenile Amur sturgeon is able to tolerate, and grow in, relatively high concentrations of saltwater. 相似文献
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We evaluated the ability of juvenile Amur sturgeon (Acipenser schrenckii) to osmoregulate and grow in saltwater. Hatchery-reared juveniles (mean weight 106.8 g, 5-month old) were transferred from
freshwater to 10, 20, and 25 salinity saltwater over a period of 20 d. We measured the growth, serum osmolality, ion concentrations,
and Na+/K+-ATPase activity. In addition, we prepared samples of gill tissue to quantify morphological changes in gill ultrastructure.
Rearing in up to 25 saltwater for 30 d had no significant effect on growth. Similarly, serum osmolality and ion concentrations
were similar to levels reported in other teleosts following acclimation to saltwater. Serum osmolality and Na+, Cl− concentrations increased significantly with the initial increase in salinity. Afterwards, levels tended to stabilize and
then decrease. Serum K+ levels did not change during acclimation to saltwater. Gill Na+/K+-ATPase activity increased initially as salinity was increased. However, the activity later decreased and, finally stabilized
at 3.7±0.1 μmol Pi/mg·prot·h in 25 saltwater (1.6 times higher than the level in those in freshwater). In fish that were held only in freshwater,
the chloride cells were located in the interlamellar regions of the filament and at the base of the lamella. Following acclimation
to 25 saltwater for 30 d, the number and size of chloride cells increased significantly. Our results suggest that juvenile
Amur sturgeon is able to tolerate, and grow in, relatively high concentrations of saltwater. 相似文献
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根据mtDNA D-loop 序列分析东海银鲳群体遗传多样性 总被引：3，自引：1，他引：2
根据线粒体D-loop序列对舟山群岛附近海域的银鲳(Pampus argenteus)群体(n=24)的遗传多样性进行了研究。通过PCR技术对线粒体D-loop序列进行扩增,获得大小约为500bp的扩增产物。PCR产物经纯化并进行序列测定后,得到了357bp的核苷酸片段。在24个个体中,共检测到14个变异位点,其中8个转换位点,5个颠换位点,1个转换与颠换同时存在的位点。运用MEGA软件计算出不同个体间的遗传距离,并根据其遗传距离构建了UPGMA和NJ系统树。DNASP软件计算出的单倍型多样性(h)、核苷酸多样性(π)及平均核苷酸差异数(k)分别为0.89、0.007与2.57。此外,岐点分布及中性检验显示,东海银鲳群体在历史上可能经历过种群扩张。研究结果表明,线粒体D-loop基因可用于银鲳群体内及群体间遗传多样性的分析。 相似文献
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采用Sephacryl S-300凝胶过滤和DEAE Fast Flow阴离子交换两种层析法分离纯化中华鲟(Acipenser sinensis)卵黄脂磷蛋白(lipovitellin,Lv),对每个峰进行SDS-PAGE电泳及油红O、甲基绿和Schiff试剂特异染色,峰Ⅱ蛋白均呈阳性,表明峰Ⅱ蛋白为中华鲟卵中的一种卵黄脂磷蛋白,SDS-PAGE电泳分析表明其由一种分子质量为43.5 ku的亚基构成。对中华鲟Lv氨基酸组成进行研究,证明其是一种含有相对较多天冬氨酸、谷氨酸、缬氨酸和亮氨酸的蛋白。 相似文献
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为探明工程建设后东海大桥风电场水域鱼类群落结构特征,作者利用等级聚类和多元统计等方法对该水域鱼类种类组成、优势种及群落结构进行分析。春、秋季共发现18种鱼类,隶属6目9科15属;鲈形目鱼类所占比例最高(50%),其中又以虾虎鱼科鱼类最高(44.4%)。春季优势种为短吻红舌鳎(Cynoglossus joyneri)、棘头梅童鱼(Collichthys lucidus)、矛尾虾虎鱼(Chaeturichthys stigmatias)和孔虾虎鱼(Trypauchen vagina),秋季优势种为棘头梅童鱼、龙头鱼(Harpadon nehereus)和凤鲚(Coilia mystus);棘头梅童鱼为春、秋季共同优势种。等级聚类和非度量多维标序排序表明,东海大桥风电场水域鱼类群落可分为春季和秋季2个组群,相似性检验(ANOSIM)显示2个组群差异极显著(R=0.851,P0.01)。生物与环境相关分析(BIOENV)表明温度和盐度是影响东海大桥风电场水域鱼类群落结构的最主要环境因子,两者结合因子与鱼类群落的相关系数为0.791。本研究发现,东海大桥风电场水域是棘头梅童鱼、凤鲚、龙头鱼等多种鱼类的育幼和索饵场所,群落结构具有典型的季节特征。 相似文献
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以体质量58.51 g±21.15 g、体长13.08 cm±1.856 cm的长鳍篮子鱼(Siganus canaliculatus)为实验材料,对其消化道指数和主要消化酶活性分布进行了研究.采用常规方法测定了长鳍篮子鱼的消化道指数,其比内脏重、比肝重、比胃重,比幽门盲囊重、比肠重、比肠长分别为0.1572±0.0230、0.0166±0.0060、0.0115±0.0070、0.004 3±0.002 1、0.020 2±0.0102、2.595±0.457;体质量与体长的回归方程为Y=0.080 6X2.5457(r=0.9777,P<0.01).蛋白酶在各消化器官中的比活力顺序为幽门盲囊>肠>肝脏>胃;淀粉酶的比活力顺序为肠>幽门盲囊>胃>肝脏;脂肪酶比活力顺序为幽门盲囊>肝脏>肠>胃;肠的总蛋白酶活、总淀粉酶活、总脂肪酶活在各消化器官中都最高.肝脏、胃、肠、幽门盲囊的A/P值分别为2.15、22.65、3.81,1.96.研究表明,肠道是长鳍篮子鱼消化食物的最重要的消化器官;根据消化道指数、消化酶分布、A/P值,表明长鳍篮子鱼是偏植食性为主的杂食性鱼类. 相似文献
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