采用人工受精获得的南方鲇Silurus meridionalis Chen胚胎和仔鱼为实验对象,以Pb(NO3)2为毒物源,在水温22.5℃条件下,观察了水体中不同质量浓度铅(Pb)暴露对南方鲇胚胎孵化率、畸形率、自主运动、孵化历时的影响,并进行了初孵仔鱼的Pb...采用人工受精获得的南方鲇Silurus meridionalis Chen胚胎和仔鱼为实验对象,以Pb(NO3)2为毒物源,在水温22.5℃条件下,观察了水体中不同质量浓度铅(Pb)暴露对南方鲇胚胎孵化率、畸形率、自主运动、孵化历时的影响,并进行了初孵仔鱼的Pb暴露毒理实验.实验结果表明,在水体中Pb2+质量浓度分别为0(对照),4,8,12和16mg/L的条件下,南方鲇胚胎孵化率随着Pb质量浓度的上升呈下降趋势,分别为84.94%,71.23%,69.75%,66.57%和64.69%,各Pb质量浓度处理组的孵化率显著低于对照组(p<0.05);且孵出的仔鱼出现心包水肿,脊柱弯曲以及尾巴弯曲退化等畸形特征,畸形率随着Pb质量浓度的升高呈上升趋势,分别为10.27%,15.28%,22.28%和36.67%,各Pb暴露组均显著高于对照组(2.37%)(p<0.05);各Pb质量浓度暴露组胚胎在出膜前期的自主运动频率分别为63.86,52.71,48.43和47.14次/min均显著低于对照组(78.00次/min)(p<0.05);各Pb质量浓度暴露组的胚胎孵化历时均显著长于对照组(p<0.05).孵化后在净水(未加入Pb(NO3)2的实验水体)中养殖的卵黄囊期仔鱼72h死亡率随着其胚胎期Pb暴露质量浓度的上升呈上升趋势,胚胎期Pb暴露质量浓度分别为0,4,8,12和16mg/L的条件下,仔鱼期的净水死亡率分别为9.45%,18.22%,20.95%,24.05%和26.29%,胚胎期各Pb质量浓度暴露组所获仔鱼的死亡率均显著高于对照组(p<0.05).根据水体Pb暴露对南方鲇初孵仔鱼急性中毒致死的观测结果推算,其96h半致死质量浓度(96hLC50)为0.32mg/L.本研究结果表明,南方鲇胚胎对水体Pb暴露的耐受性高于其初孵仔鱼,可能与南方鲇的受精卵卵膜较厚,对水体中的Pb2+进入胚胎具有较大的阻滞作用有关.展开更多
实验室循环水养殖系统中,27．5℃条件下,以对照组(添加0％碳水化合物)和处理组(添加12％碳水化合物)的人工配合饲料喂养南方鲇(Silurus meridionalis Chen)幼鱼(38～42 g),在喂养0,2,4周后分别测定实验鱼胃、肠、胰的淀粉酶和蛋白酶活...实验室循环水养殖系统中,27．5℃条件下,以对照组(添加0％碳水化合物)和处理组(添加12％碳水化合物)的人工配合饲料喂养南方鲇(Silurus meridionalis Chen)幼鱼(38～42 g),在喂养0,2,4周后分别测定实验鱼胃、肠、胰的淀粉酶和蛋白酶活性．结果显示:胃、肠、胰淀粉酶活性在对照组与处理组之间差异均不显著;南方鲇幼鱼的淀粉酶活性的基础水平(未经实验处理的0周)在胃、肠分别为0．073,0．108 U／mg,高于某些肉食性鱼类的相应水平;蛋白酶活性在摄入碳水化合物后却产生了明显的变化(p<0．05)．研究表明:南方鲇幼鱼淀粉酶活性对饲料碳水化合物的变化具有相对保守性,而蛋白酶活性对碳水化合物的变化则表现出明显的反应．本研究提示,南方鲇幼鱼能够利用饲料碳水化合物可能与其淀粉酶活性的基础水平较高有关．展开更多
The large-scale green tide caused by Ulva has occurred successively in the Yellow Sea since 2007,and new events of green tide also continued to appear in nearby sea areas,indicating an undergoing rapid development of ...The large-scale green tide caused by Ulva has occurred successively in the Yellow Sea since 2007,and new events of green tide also continued to appear in nearby sea areas,indicating an undergoing rapid development of occurrence patterns for harmful macroalgal blooms(HMBs)along coastal China.In August 2021,a green tide occurred for the first time in Bayuquan sea area of Yingkou city,Liaoning Province in the Bohai Sea.In this study,morphological and molecular approaches were used to identify the causative species as U.meridionalis,an alien subtropical alga previously found to dominate green tides in the South China Sea.According to the hydrological data of Bayuquan in summer 2021,combined with morphological and developmental observations for this alga,we hypothesized that the disturbance caused by the typhoon In-Fa might have detached the local U.meridionalis from substrates,especially for those thalli with poorly developed holdfasts,and the ensuing wave-free period with unusually high temperature,which fell in the reported optimum growth temperature for U.meridionalis,might have provided the favorable conditions for the final bloom of the floating seaweeds.This is the first report on the bloom of subtropical U.meridionalis in the north temperate sea zone,indicating that the ecological risk of causing green tides in the future by this rapidly spreading species deserves high attention.展开更多
The pepsin and trypsin activities and some of the properties of the two enzymes of southern sheatfish larvae were studied. The results were as follows: the highest level of trypsin activity is in the foregut in all...The pepsin and trypsin activities and some of the properties of the two enzymes of southern sheatfish larvae were studied. The results were as follows: the highest level of trypsin activity is in the foregut in all measured tissues; from foregut to hindgut, trypsin activities decrease; the pH optimum of trypsin activity is pH9.0; the strongest pepsin activity is in the stomach; the proper density of haemoglobin for detecting pepsin activity is 1.0%. These data are useful in solving applied nutritional problems, such as the adequacy of artificial food to the digestive abilities of the fish.展开更多
文摘采用人工受精获得的南方鲇Silurus meridionalis Chen胚胎和仔鱼为实验对象,以Pb(NO3)2为毒物源,在水温22.5℃条件下,观察了水体中不同质量浓度铅(Pb)暴露对南方鲇胚胎孵化率、畸形率、自主运动、孵化历时的影响,并进行了初孵仔鱼的Pb暴露毒理实验.实验结果表明,在水体中Pb2+质量浓度分别为0(对照),4,8,12和16mg/L的条件下,南方鲇胚胎孵化率随着Pb质量浓度的上升呈下降趋势,分别为84.94%,71.23%,69.75%,66.57%和64.69%,各Pb质量浓度处理组的孵化率显著低于对照组(p<0.05);且孵出的仔鱼出现心包水肿,脊柱弯曲以及尾巴弯曲退化等畸形特征,畸形率随着Pb质量浓度的升高呈上升趋势,分别为10.27%,15.28%,22.28%和36.67%,各Pb暴露组均显著高于对照组(2.37%)(p<0.05);各Pb质量浓度暴露组胚胎在出膜前期的自主运动频率分别为63.86,52.71,48.43和47.14次/min均显著低于对照组(78.00次/min)(p<0.05);各Pb质量浓度暴露组的胚胎孵化历时均显著长于对照组(p<0.05).孵化后在净水(未加入Pb(NO3)2的实验水体)中养殖的卵黄囊期仔鱼72h死亡率随着其胚胎期Pb暴露质量浓度的上升呈上升趋势,胚胎期Pb暴露质量浓度分别为0,4,8,12和16mg/L的条件下,仔鱼期的净水死亡率分别为9.45%,18.22%,20.95%,24.05%和26.29%,胚胎期各Pb质量浓度暴露组所获仔鱼的死亡率均显著高于对照组(p<0.05).根据水体Pb暴露对南方鲇初孵仔鱼急性中毒致死的观测结果推算,其96h半致死质量浓度(96hLC50)为0.32mg/L.本研究结果表明,南方鲇胚胎对水体Pb暴露的耐受性高于其初孵仔鱼,可能与南方鲇的受精卵卵膜较厚,对水体中的Pb2+进入胚胎具有较大的阻滞作用有关.
文摘实验室循环水养殖系统中,27．5℃条件下,以对照组(添加0％碳水化合物)和处理组(添加12％碳水化合物)的人工配合饲料喂养南方鲇(Silurus meridionalis Chen)幼鱼(38～42 g),在喂养0,2,4周后分别测定实验鱼胃、肠、胰的淀粉酶和蛋白酶活性．结果显示:胃、肠、胰淀粉酶活性在对照组与处理组之间差异均不显著;南方鲇幼鱼的淀粉酶活性的基础水平(未经实验处理的0周)在胃、肠分别为0．073,0．108 U／mg,高于某些肉食性鱼类的相应水平;蛋白酶活性在摄入碳水化合物后却产生了明显的变化(p<0．05)．研究表明:南方鲇幼鱼淀粉酶活性对饲料碳水化合物的变化具有相对保守性,而蛋白酶活性对碳水化合物的变化则表现出明显的反应．本研究提示,南方鲇幼鱼能够利用饲料碳水化合物可能与其淀粉酶活性的基础水平较高有关．
基金Supported by the Science&Technology Basic Resources Investigation Program of China(No.2018FY100205)the National Natural Science Foundation of China(No.41776153)+4 种基金the National Key R&D Program of China(No.2018YFD0901500)the Key Deployment Project of Centre for Ocean Mega-Research of ScienceChinese Academy of Science(No.COMS2019Q05)the Key R&D Program of Shandong Province(No.2019GSF107012)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23050302)。
文摘The large-scale green tide caused by Ulva has occurred successively in the Yellow Sea since 2007,and new events of green tide also continued to appear in nearby sea areas,indicating an undergoing rapid development of occurrence patterns for harmful macroalgal blooms(HMBs)along coastal China.In August 2021,a green tide occurred for the first time in Bayuquan sea area of Yingkou city,Liaoning Province in the Bohai Sea.In this study,morphological and molecular approaches were used to identify the causative species as U.meridionalis,an alien subtropical alga previously found to dominate green tides in the South China Sea.According to the hydrological data of Bayuquan in summer 2021,combined with morphological and developmental observations for this alga,we hypothesized that the disturbance caused by the typhoon In-Fa might have detached the local U.meridionalis from substrates,especially for those thalli with poorly developed holdfasts,and the ensuing wave-free period with unusually high temperature,which fell in the reported optimum growth temperature for U.meridionalis,might have provided the favorable conditions for the final bloom of the floating seaweeds.This is the first report on the bloom of subtropical U.meridionalis in the north temperate sea zone,indicating that the ecological risk of causing green tides in the future by this rapidly spreading species deserves high attention.
文摘The pepsin and trypsin activities and some of the properties of the two enzymes of southern sheatfish larvae were studied. The results were as follows: the highest level of trypsin activity is in the foregut in all measured tissues; from foregut to hindgut, trypsin activities decrease; the pH optimum of trypsin activity is pH9.0; the strongest pepsin activity is in the stomach; the proper density of haemoglobin for detecting pepsin activity is 1.0%. These data are useful in solving applied nutritional problems, such as the adequacy of artificial food to the digestive abilities of the fish.
