保护和发展黑龙江鲟渔业

鲟科鱼类是黑龙江干流重要经济鱼类。根据黑龙江鲟科鱼类资源现状、群体结构变动情况及其生物学特点.阐明了保护和发展黑龙江鲟科鱼类的必要性并提出了建议。     

达氟沙星对施氏鲟的急性毒性及组织残留检测

将施氏鲟(Acipenser scherenscki,体重75～95g)暂养于室内玻璃水族箱内7d后进行实验。所用达氟沙星(Danofloxacin)纯度为99．5％。分别以剂量800、l040、1352、1757．60、2284．88和2970．34mg／(kg体重)对施氏鲟进行口灌,以400、440、484、532．4、585．6和644．2mg,／(kg体重)进行腹腔注射达氟沙星水溶液,给药后连续10d观察实验鱼的行为及死亡情况。用改进的寇氏法计算得出施氏鲟腹腔注射达氟沙星的LD50为429．47mg／(kg体重),LD50的95％可信限为425．22～433．66mg／(kg体重)。口灌达氟沙星LD50为l502．10mg／(kg体重),95％可信区间范围为1307．89～1738．60mg／(k体重)。对染毒死亡鱼及对照组实验鱼分别进行组织切片,并分别进行光镜及电镜观察。光镜观察结果表明,染毒死亡鱼的肝细胞的索状结构消失,肝组织呈弥漫性坏死,肝细胞肿胀,有些肝细胞失去正常的多角形形状,细胞核肿胀变形;窦状隙腔变窄,其中的红细胞形状也不同程度发生了改变。染毒死亡鱼的肝细胞的超微结构显示,肝细胞内充满脂滴,肝细胞核萎缩、消失,线粒体脊断裂,线粒体破裂,粗面内质网结构疏松有断裂,滑面内质网数量明显减少,溶酶体破裂。用高效液相色谱法测定以10mg/(k体重)剂量连续4次口灌给药后,达氟沙星在施氏鲟血浆、肝脏、肾脏、肌肉和鳃组织中的药物水平,实验结果表明,达氟沙星在施氏鲟全身组织均有分布,用药第9天后达氟沙星在施氏鲟体内消除速度很快,各组织药物水平均在最低检测限以下,其中肌肉和鳃在第6天就可降到0．005μg/(g组织)以下,肝脏和肾脏在第9天、血浆在第7天均检测不到,检测发现肝脏、肾脏中的药物水平远远高于血浆、肌肉和鳃组织中的血药水平。建议肝脏和肾脏可作为达氟沙星的残留检测的指示组织。     

中华鲟产卵洄游群体结构和资源量估算的研究

通过分析与比较,获得了能准确反映体重与体长、胸围关系的回归公式:雌鲟y=1.832×10~(-4)(x_1x_2)~(1.337)(n=29,γ=0.980,sd=12.095,C.V=5.28％);雄鲟y=2.490×10~(-5)(x_1x_2)~(1.527)(n=52,γ=0.965,Sd=5.601,C.V=6.40％)。     

不同pH和温度条件下杂交鲟胃中消化酶活性的变化

以杂交鲟(Husohuso♀×A ruthenus♂)为研究材料,测定不同pH及不同温度条件下胃中蛋白酶、淀粉酶和脂肪酶的活性。结果表明,当pH2 2～7 8时,蛋白酶随pH的升高酶活性逐渐降低,淀粉酶及脂肪酶在偏碱性条件下才具有一定的酶活性,而且活性较弱。在20～40℃范围内,蛋白酶活性随温度的升高而增加,淀粉酶、脂肪酶分别在35℃和25℃处达最大酶活性。     

鲟形目鱼类和渔业

本文论述了国内外鲟形目鱼类和渔业.包括三部分:1.鲟形目的种类和分布:2.鲟形目的生物学特征;3.世界上鲟鱼和白鲟渔业,并着重讨论该鱼类资源在我国的开发和利用.     

Trotline efficiencies and catch rates in a large river

Trotlines have proved to be an effective collection method for riverine fish species, but an understanding of the interaction between fish and gear post‐deployment is lacking. The objectives of this study were to use trotlines rigged with hook timers that record the time when fish are hooked to determine the activation rate of hook timers, to determine the retention rate of fish on trot lines, to document hourly catch rates and to document whether hooking duration causes stress or mortality. Four thousand hook timers were deployed in an 80.5 rkm reach of the Missouri River during April 2011, resulting in a mean catch rate of 14.6 fish per line, while 3.1 timers per line were activated but did not capture a fish. Over half of all fish were captured within 4 h post‐deployment. Stress and mortality associated with trotlines did not appear to be related to hooking duration. This study showed that hourly catch rates and retention rates can be ascertained from the use of trotlines rigged with hook timers. Information gathered from this study and further investigation with hook timers could aid in targeting specific time of day and set duration to collect river fish more efficiently, especially sturgeons, Scaphirhynchus species.     

运动功能相关的中华鲟和西伯利亚鲟幼鱼侧视形态比较研究

通过选取11个侧视形态特征度量进行主成分分析(principal component analysis,PCA),同时设置26个标记点进行相对扭曲分析(relative warp analysis,RWA),比较了中华鲟(Acipenser sinensis)和西伯利亚鲟(A.baerii)幼鱼在侧视形态上的差异以及相对扭曲分析和传统多元分析在鲟鱼形态研究中的优劣。结合前期对它们的有氧游泳能力比较结果(西伯利亚鲟比中华鲟强25%),分析了鲟鱼形态的水动力功能。主成分分析比较表明,中华鲟头长、头高、背鳍前基点之后的躯干高度、尾柄长、背鳍前缘长度均显著大于西伯利亚鲟(P<0.05),而尾鳍上叶显著短于西伯利亚鲟(P<0.05)。相对扭曲分析计算样本的几何信息并可视化统计结果,表明中华鲟的吻厚、吻长、头高、头长、躯干后半段高、背鳍前缘长显著大于西伯利亚鲟,而尾柄长和尾鳍上下叶长显著小于西伯利亚鲟(P<0.001)。上述形态特征直接影响着两种鲟鱼的游泳能力。     

Effect of chloride on nitrite‐induced methaemoglobinemia in Atlantic sturgeon,Acipenser oxyrinchus oxyrinchus (Mitchill)

We evaluated the effects of chloride concentration on the clinical pathology in juvenile Atlantic sturgeon, Acipenser oxyrinchus oxyrinchus (Mitchill), following semi‐static exposures to 1 mg L^?1 nitrite for 96 h. In spring water naturally low in chloride (5 mg L^?1), plasma nitrite concentrated to more than 40× environmental levels resulting in a severe methaemoglobinemia characterized by torpid behaviour, 30‐fold increase in methaemoglobin fraction, anaemia, leucopenia and hyperkalaemia. Loss of intracellular water and potassium to extracellular space may have resulted in hyperkalaemia and haemodilution. Fish survived nitrite exposure, but 60% of torpid fish died following capture and tissue sampling. Fish acclimated to 10‐fold higher chloride content (55 mg L^?1) did not concentrate nitrite in the plasma above environmental levels or develop methaemoglobinemia, but did exhibit similar haematology and plasma chemistry changes. Plasma nitrite returned to preexposure levels by 14 days following nitrite exposures, but severity of clinical pathology changes persisted or increased, suggesting that Atlantic sturgeon have reduced capacity to recover from methaemoglobinemia. Fish that survive methaemoglobinemia may be susceptible to mortality from the cumulative effects of intoxication, handling and other stresses for two or more weeks following nitrite remediation. Chloride buffering in aquaculture systems reduces the toxic effects of nitrite accumulation.     

施氏鲟在静水池塘养殖的生长特性研究

对1龄施氏鲟(Acipenser schrenckii)在静水池塘养殖条件下的生长特性进行了研究.结果表明:平均体全长25.99 cm、平均体重53.70 g的施氏鲟经过60 d土质静水池塘的培育,体全长增长58.83%,体重增长360.20%.体重与体全长呈幂函数关系,关系式为W=0.000 6 L3.484(R2=...     

贵州山区鲟鱼健康养殖技术

为贵州山区鲟鱼健康养殖提供科学依据,通过试验,从水源条件、养殖场所、品种、养殖密度、饲料和饲养管理等方面总结出了在贵州山区开展鲟鱼流水健康养殖的技术要点,并对鲟鱼养殖技术进行了推广应用.