The essay studies the influence of the different intensities of fishing stress on body weight （7.30 ± 1.48） g of red crucian carp juvenile body length, weight, fatness, feeding rate, specific growth rate, food ...The essay studies the influence of the different intensities of fishing stress on body weight （7.30 ± 1.48） g of red crucian carp juvenile body length, weight, fatness, feeding rate, specific growth rate, food conversion rate, intestinal protease, amylase and immunoglobulin. The result showed that body length, weight, fatness, feeding rate, specific growth rate of red crucian carp juvenile were significantly inhibited from fishing stress compared with the control group, and the magnitude of the inhibitory effect increased with the time going and increased. Fishing stress could increase the food conversion rate of red crucian carp juvenile, and the different intensity stress had no significant different influence. The intestinal protease activity decreased in the beginning, then increased, and was consistent with the level of the control group ultimately. High-stress group accelerated the decline of intestinal amylase activity of the juvenile. The stress increased the number of immunoglobulin of juvenile red crucian carp significantly, but the increase disappeard with the stress time extended.展开更多
We used data from bottom trawl surveys to study the factors influencing the abundance of small yellow croaker, Larimichthys polyactis, in the southern Yellow Sea （SYS） and the East China Sea （ECS）. The resource de...We used data from bottom trawl surveys to study the factors influencing the abundance of small yellow croaker, Larimichthys polyactis, in the southern Yellow Sea （SYS） and the East China Sea （ECS）. The resource density index （RD1） was generally higher in summer and autumn than in spring and winter. RDIs were also significantly greater in the SYS than in the ECS in summer and autumn. The bottom water salinity and depth of spatial distribution of small yellow croaker was similar between the two areas in summer, but different in other seasons. Regression analysis suggested that environmental factors such as bottom water temperature, salinity, and depth influenced the RDIs in summer in these areas. Growth condition factor （GCF） in the two areas varied monthly and the croaker in the SYS grew more slowly than those in the ECS. This was likely due to the low bottom temperature of the Yellow Sea Cold Water Mass in summer and autumn or to higher human fishing pressure in the ECS. To ensure sustainable utilization of the croaker stocks in these regions, we recommend reducing the fishing intensity, increasing the cod-end mesh size, and improving the protection of juveniles.展开更多
The present study compared vertebral deformities of hatchery-reared and wild-caught juvenile Japanese flounder, Paralichthys olivaceus. A total of 362 hatchery-reared flounder （total length 122.5- 155.8 mm） were col...The present study compared vertebral deformities of hatchery-reared and wild-caught juvenile Japanese flounder, Paralichthys olivaceus. A total of 362 hatchery-reared flounder （total length 122.5- 155.8 mm） were collected from three commercial hatcheries located in Yantai, East China, and 89 wild fish （total length 124.7 161.3 mm） were caught offYangma Island near Yantai City （37°27′N, 121°36′E）. All the fish were dissected, photographed, and images of the axial skeleton were examined for vertebral deformities. Compared with wild-caught flounder in which no deformed vertebrae were detected, 48 （13.3%） hatchery- reared fish had deformed vertebrae. The deformities were classified as compression, compression-ankylosis, and dislocation-ankylosis. The vertebral deformities were mainly localized between post-cranial vertebra 1 and 3, with vertebrae number 1 as the most commonly deformed. The causative factors leading to vertebral deformities in reared Japanese flounder may be related to unfavorable temperature conditions, inflammation, damage, or rupture to the intervertebral ligaments under rearing conditions. Furthermore, no significant difference in the total number of vertebral bodies was observed between wild-caught （38.8±0.4） and hatchery-reared flounder （38.1±0.9） （P〉0.05）. However, the number of vertebral bodies of hatchery-reared and wild-caught flounder ranged from 35 to 39 and from 38 to 39, respectively.展开更多
The concentrations of seven essential trace elements in 149 freshwater fish from eight fish species （European eel, bream, common carp, European catfish, roach, perch, pike and pikeperch） from five different French f...The concentrations of seven essential trace elements in 149 freshwater fish from eight fish species （European eel, bream, common carp, European catfish, roach, perch, pike and pikeperch） from five different French fishing areas from contaminated and control sites were measured by inductively coupled plasma mass spectrometry after microwave digestion under pressure. Differences in the concentration of elements in the muscles of these species were examined and the mean levels were compared for each species with previous French and European studies. The condition factor and the differences between the control and contaminated sites and between predatory and non-predatory groups, with respect to the concentration of these elements, were also studied.展开更多
文摘The essay studies the influence of the different intensities of fishing stress on body weight （7.30 ± 1.48） g of red crucian carp juvenile body length, weight, fatness, feeding rate, specific growth rate, food conversion rate, intestinal protease, amylase and immunoglobulin. The result showed that body length, weight, fatness, feeding rate, specific growth rate of red crucian carp juvenile were significantly inhibited from fishing stress compared with the control group, and the magnitude of the inhibitory effect increased with the time going and increased. Fishing stress could increase the food conversion rate of red crucian carp juvenile, and the different intensity stress had no significant different influence. The intestinal protease activity decreased in the beginning, then increased, and was consistent with the level of the control group ultimately. High-stress group accelerated the decline of intestinal amylase activity of the juvenile. The stress increased the number of immunoglobulin of juvenile red crucian carp significantly, but the increase disappeard with the stress time extended.
基金Supported by the National Natural Science Foundation of China for Creative Research Groups (No. 40821004)the National Key Technology Research and Development Program (No. 2007BAD43B01)the Open Fund of Key Laboratory of Marine Ecology and Environmental Science, Institute of Oceanology, Chinese Academy of Sciences (No. KLMEES201001)
文摘We used data from bottom trawl surveys to study the factors influencing the abundance of small yellow croaker, Larimichthys polyactis, in the southern Yellow Sea （SYS） and the East China Sea （ECS）. The resource density index （RD1） was generally higher in summer and autumn than in spring and winter. RDIs were also significantly greater in the SYS than in the ECS in summer and autumn. The bottom water salinity and depth of spatial distribution of small yellow croaker was similar between the two areas in summer, but different in other seasons. Regression analysis suggested that environmental factors such as bottom water temperature, salinity, and depth influenced the RDIs in summer in these areas. Growth condition factor （GCF） in the two areas varied monthly and the croaker in the SYS grew more slowly than those in the ECS. This was likely due to the low bottom temperature of the Yellow Sea Cold Water Mass in summer and autumn or to higher human fishing pressure in the ECS. To ensure sustainable utilization of the croaker stocks in these regions, we recommend reducing the fishing intensity, increasing the cod-end mesh size, and improving the protection of juveniles.
基金Supported by the Special Fund for Agro-Scientific Research in the Public Interest(No.201003068)the Open Foundation from Ocean Fishery Science and Technology in the Most Important Subjects of Zhejiang,China
文摘The present study compared vertebral deformities of hatchery-reared and wild-caught juvenile Japanese flounder, Paralichthys olivaceus. A total of 362 hatchery-reared flounder （total length 122.5- 155.8 mm） were collected from three commercial hatcheries located in Yantai, East China, and 89 wild fish （total length 124.7 161.3 mm） were caught offYangma Island near Yantai City （37°27′N, 121°36′E）. All the fish were dissected, photographed, and images of the axial skeleton were examined for vertebral deformities. Compared with wild-caught flounder in which no deformed vertebrae were detected, 48 （13.3%） hatchery- reared fish had deformed vertebrae. The deformities were classified as compression, compression-ankylosis, and dislocation-ankylosis. The vertebral deformities were mainly localized between post-cranial vertebra 1 and 3, with vertebrae number 1 as the most commonly deformed. The causative factors leading to vertebral deformities in reared Japanese flounder may be related to unfavorable temperature conditions, inflammation, damage, or rupture to the intervertebral ligaments under rearing conditions. Furthermore, no significant difference in the total number of vertebral bodies was observed between wild-caught （38.8±0.4） and hatchery-reared flounder （38.1±0.9） （P〉0.05）. However, the number of vertebral bodies of hatchery-reared and wild-caught flounder ranged from 35 to 39 and from 38 to 39, respectively.
文摘The concentrations of seven essential trace elements in 149 freshwater fish from eight fish species （European eel, bream, common carp, European catfish, roach, perch, pike and pikeperch） from five different French fishing areas from contaminated and control sites were measured by inductively coupled plasma mass spectrometry after microwave digestion under pressure. Differences in the concentration of elements in the muscles of these species were examined and the mean levels were compared for each species with previous French and European studies. The condition factor and the differences between the control and contaminated sites and between predatory and non-predatory groups, with respect to the concentration of these elements, were also studied.
