The objectives of the present study were to evaluate the yolk-sac and oil globule absorption and point of no return （PNR） ofpikeperch （Sander lucioperca L.） larvae. Artificial propagation ofpikeperch was performed...The objectives of the present study were to evaluate the yolk-sac and oil globule absorption and point of no return （PNR） ofpikeperch （Sander lucioperca L.） larvae. Artificial propagation ofpikeperch was performed at （15±2）℃. Yolk-sac absorption, oil globule absorption, larval growth and the first initial feeding rate were observed to analyze the early growth and to determine the PNR of pikeperch larvae. The total length of newly hatched （0 day after hatching, DAH） pikeperch larvae was （4.25±0.22） mm and the volume of the yolk-sac and the oil globule was （0.30±0.12）mm^3 and （5.14±2.28） 10-2 mm^3 respectively. The yolk-sac and the oil globule were exhausted at 11 DAH and 14 DAH, respectively. Pikeperch larvae began feeding at 8 DAH with an initial feeding rate about 10.0%. From 9 to 14 DAH, the initial feeding rate increased rapidly, and reached its highest （about 82.7%） at 14 DAH. It declined thereafter, 48.9% at 15 DAH and 35.6% at 16 DAH, thus the pikeperch larvae reached PNR by 15-16 DAH. The appropriate first feeding time for the pikeperch larvae is 11-12 DAH, when the initial feeding rate is higher than half of the maximum initial feeding rate.展开更多
The present study examined the influence of leucine metabolite β-hydroxy-β-methylbutyrate （HMB） on the nonspecific cellular and humoral defence mechanisms and protection against Yersinia ruckeri and Aeromonas salm...The present study examined the influence of leucine metabolite β-hydroxy-β-methylbutyrate （HMB） on the nonspecific cellular and humoral defence mechanisms and protection against Yersinia ruckeri and Aeromonas salmonicida in juvenile pikeperch （Sander lucioperca）. The fish was fed with a commercial trout pellets, containing either 0 （control group） or 50 mg HMB kg^-1 body weight day^-1 （HMB fed group）. After four weeks feeding, 20 pikeperch from each group were anaesthetised and blood and pronephros samples were taken. The levels of the following immunological parameters were measured： respiratory burst activity of phagocytes, potential killing activity of phagocytes, lymphocytes proliferation stimulated by concanavaline A or lipopolisaccharide, lysozyme activity in serum, ceruloplasmin activity in serum, total protein in serum and total immunoglobulin （Ig） level in serum. A disease challenge test using Yersinia ruckeri or Aeromonas salmonicida was conducted after 4 weeks of feeding. The levels of all immunological parameters excluding ceruloplasmin activity and total protein in serum were statistically significantly higher （P 〈 0.05） in the HMB treated group compared to the control group. Feeding with HMB has led to a significant decrease in the mortality after the challenge trial with Y. ruckeri （30% lower mortality than in the control group） and with theA. salmonicida （40% lower mortality than in the control group）. The current study strongly suggests that feeding pikeperch with HMB in dose 50 mg kg^-1 body weight day^-1 may improve the innate immunity and decrease the mortality rates after experimental infection with pathogenic bacteria Y. ruckeri and A. salmonicida.展开更多
Analysis of historical and recent data is essential to understand how eutrophication and/or climate change might trigger shifts in the feeding mode of fish and trophic dynamics of shallow lakes. To assess long-term ch...Analysis of historical and recent data is essential to understand how eutrophication and/or climate change might trigger shifts in the feeding mode of fish and trophic dynamics of shallow lakes. To assess long-term changes in the diet and growth of juvenile pikeperch (Sander lucioperca), the prey selection and growth of pikeperch fry from Lake V?rtsj?rv was investigated in 2007 - 2010 and compared with data from 1920 to 1970. Over the observed period, larger cladocerans have become less frequent in the diet as eutrophication has altered the zooplankton community. Furthermore, climate change has triggered a mismatch between the predator and its prey: the smelt population has collapsed but other fish fries are too large for YOY (young-of-the-year) pikeperch. However, the mean length of fish has decreased mainly due to the postponed diet shift.展开更多
The purpose of the present study was to investigate the muscle protein expression in two pikeperches(Stizostedion lucioperca and S.volgense)through intra-and intermyomeric composition of white muscles.Using denaturing...The purpose of the present study was to investigate the muscle protein expression in two pikeperches(Stizostedion lucioperca and S.volgense)through intra-and intermyomeric composition of white muscles.Using denaturing 10%sodium dodecylsulfate-polyacrylamide gel electrophoresis,muscle protein expression was studied in relation to within-and between-species morphological development,sex,maturity and age of pikeperches.Myosin,actin and troponin have a distinct role in the contraction and length tension of muscle fibers of these species.No obvious intramyomeric differences were found in the myosin heavy chain of both species.Myosin light chains(15-38 kDa)have different expression in different age groups.The muscle protein of the fingerling and adult S.lucioperca had high molecular weight(50 kDa)myosin in contrast to the other Percid species.The molecular weight of actins increased comparatively in low-age-group fish.ATP is stored in myosin and released to cause contraction when myosin comes in contact with actin of the experimental fish.Troponin regulates increasing concentration of lightchain myosin in mature fish.Because troponin T has been implicated in the regulation of skeletal muscle kinetics,muscle contraction kinetics was predicted in different age groups.The muscle proteins of both sexes of these species have polymorphism in various age groups but have no difference in similar aged fish.No muscle protein dimorphism was found in these Percid species.The white muscle protein composition and contractile properties affect power production during fast,unsteady movement and swimming.展开更多
基金Supported by the Science Fund of Jiangsu Province(No.BY2015039-10)the Fund of Jiangsu Province Collaborative Center of Regional Modern Agriculture&Environmental Protection(No.HSXT219)the Science Fund of Changshu Science and Technology Bureau,China(No.CN201408)
文摘The objectives of the present study were to evaluate the yolk-sac and oil globule absorption and point of no return （PNR） ofpikeperch （Sander lucioperca L.） larvae. Artificial propagation ofpikeperch was performed at （15±2）℃. Yolk-sac absorption, oil globule absorption, larval growth and the first initial feeding rate were observed to analyze the early growth and to determine the PNR of pikeperch larvae. The total length of newly hatched （0 day after hatching, DAH） pikeperch larvae was （4.25±0.22） mm and the volume of the yolk-sac and the oil globule was （0.30±0.12）mm^3 and （5.14±2.28） 10-2 mm^3 respectively. The yolk-sac and the oil globule were exhausted at 11 DAH and 14 DAH, respectively. Pikeperch larvae began feeding at 8 DAH with an initial feeding rate about 10.0%. From 9 to 14 DAH, the initial feeding rate increased rapidly, and reached its highest （about 82.7%） at 14 DAH. It declined thereafter, 48.9% at 15 DAH and 35.6% at 16 DAH, thus the pikeperch larvae reached PNR by 15-16 DAH. The appropriate first feeding time for the pikeperch larvae is 11-12 DAH, when the initial feeding rate is higher than half of the maximum initial feeding rate.
文摘The present study examined the influence of leucine metabolite β-hydroxy-β-methylbutyrate （HMB） on the nonspecific cellular and humoral defence mechanisms and protection against Yersinia ruckeri and Aeromonas salmonicida in juvenile pikeperch （Sander lucioperca）. The fish was fed with a commercial trout pellets, containing either 0 （control group） or 50 mg HMB kg^-1 body weight day^-1 （HMB fed group）. After four weeks feeding, 20 pikeperch from each group were anaesthetised and blood and pronephros samples were taken. The levels of the following immunological parameters were measured： respiratory burst activity of phagocytes, potential killing activity of phagocytes, lymphocytes proliferation stimulated by concanavaline A or lipopolisaccharide, lysozyme activity in serum, ceruloplasmin activity in serum, total protein in serum and total immunoglobulin （Ig） level in serum. A disease challenge test using Yersinia ruckeri or Aeromonas salmonicida was conducted after 4 weeks of feeding. The levels of all immunological parameters excluding ceruloplasmin activity and total protein in serum were statistically significantly higher （P 〈 0.05） in the HMB treated group compared to the control group. Feeding with HMB has led to a significant decrease in the mortality after the challenge trial with Y. ruckeri （30% lower mortality than in the control group） and with theA. salmonicida （40% lower mortality than in the control group）. The current study strongly suggests that feeding pikeperch with HMB in dose 50 mg kg^-1 body weight day^-1 may improve the innate immunity and decrease the mortality rates after experimental infection with pathogenic bacteria Y. ruckeri and A. salmonicida.
文摘Analysis of historical and recent data is essential to understand how eutrophication and/or climate change might trigger shifts in the feeding mode of fish and trophic dynamics of shallow lakes. To assess long-term changes in the diet and growth of juvenile pikeperch (Sander lucioperca), the prey selection and growth of pikeperch fry from Lake V?rtsj?rv was investigated in 2007 - 2010 and compared with data from 1920 to 1970. Over the observed period, larger cladocerans have become less frequent in the diet as eutrophication has altered the zooplankton community. Furthermore, climate change has triggered a mismatch between the predator and its prey: the smelt population has collapsed but other fish fries are too large for YOY (young-of-the-year) pikeperch. However, the mean length of fish has decreased mainly due to the postponed diet shift.
文摘The purpose of the present study was to investigate the muscle protein expression in two pikeperches(Stizostedion lucioperca and S.volgense)through intra-and intermyomeric composition of white muscles.Using denaturing 10%sodium dodecylsulfate-polyacrylamide gel electrophoresis,muscle protein expression was studied in relation to within-and between-species morphological development,sex,maturity and age of pikeperches.Myosin,actin and troponin have a distinct role in the contraction and length tension of muscle fibers of these species.No obvious intramyomeric differences were found in the myosin heavy chain of both species.Myosin light chains(15-38 kDa)have different expression in different age groups.The muscle protein of the fingerling and adult S.lucioperca had high molecular weight(50 kDa)myosin in contrast to the other Percid species.The molecular weight of actins increased comparatively in low-age-group fish.ATP is stored in myosin and released to cause contraction when myosin comes in contact with actin of the experimental fish.Troponin regulates increasing concentration of lightchain myosin in mature fish.Because troponin T has been implicated in the regulation of skeletal muscle kinetics,muscle contraction kinetics was predicted in different age groups.The muscle proteins of both sexes of these species have polymorphism in various age groups but have no difference in similar aged fish.No muscle protein dimorphism was found in these Percid species.The white muscle protein composition and contractile properties affect power production during fast,unsteady movement and swimming.
