This study was conducted to evaluate the critical thermal maximum(CTMax), the routine metabolism rate(MO_2) and the limiting oxygen saturation(LOS) of three salmonids with four different body weights ranging from 16 g...This study was conducted to evaluate the critical thermal maximum(CTMax), the routine metabolism rate(MO_2) and the limiting oxygen saturation(LOS) of three salmonids with four different body weights ranging from 16 g to 131 g. The CTMax was estimated at three different heating rates including 0.5℃ min^(-1), 1℃ h^(-1) and 2℃ d^(-1). Results showed that the CTMax of maple trout(Oncorhynchus mykiss) was the highest, which was followed by steelhead trout(O. mykiss) and Atlantic salmon(Salmon salar). The CTMax of the salmonid fish decreased with the increment of body weight, and was significantly influenced by the heating rate. The MO_2 of the salmonid fish increased with the increment of temperature, and decreased with the increment of body weight. Suffocation points of the fish decreased with increasing body weight and temperature. Steelhead trout was more tolerant to hypoxia than maple trout and Atlantic salmon, while the MO_2 of Atlantic salmon was the highest among these three salmonids. The LOS of the fish generally had a positive trend with temperature and body weight, and the LOS of steelhead trout was significantly lower than that of maple trout and Atlantic salmon. In conclusion, maple trout was the most tolerant kind to high temperature, while steelhead trout was the most tolerant to hypoxia among three kinds of salmonids. Moreover, the abilities to tolerate higher temperature of three salmonids were affected by their body weight and the heating rate, while the abilities to tolerate hypoxia were influenced by their body weight and the water temperature.展开更多
In this study, the changes of the fatty acid composition of phospholipid in different tissues(muscle, heart, brain and spleen) of steelhead trout(Oncorhynchus mykiss) were analyzed when the water temperature decreased...In this study, the changes of the fatty acid composition of phospholipid in different tissues(muscle, heart, brain and spleen) of steelhead trout(Oncorhynchus mykiss) were analyzed when the water temperature decreased gradually from 16 to 12℃℃, 8℃, 6℃, 4℃, 2 and 1℃℃. Three fish individuals each tank(average weight 70.32 g ± 9.12 g) were collected and used to analysis at each designed temperatures. At normal temperature(16℃), the fatty acid composition of phospholipid of muscle and heart was similar each other. The highest concentration of saturate fatty acids(SFA) was found in the phospholipid of spleen. The brain phospholipid contained higher oleic acid(18:1 n9) than the phospholipid of other tissues at 16℃. When the environmental temperature decreased, the concentration of unsaturated fatty acids of phospholipids in all tissues increased, and accordingly the ratio pf the unsaturated to saturated fatty acids(U/S) and unsaturation index(UI) increased, indicating that steelhead trout can compensate temperature-dependent changes in membrane fluidity by remodeling the fatty acid composition of phospholipids. The changes in the fatty acid composition of phospholipid were tissue-specific. At the early stages of the experiment(16 to 8℃℃), the fatty acid composition of phospholipid changed remarkably in muscle, heart, and spleen. When temperature decreased to less than 8℃, an obvious response of phospholipid fatty acid was observed in all tissues. The change of phospholipid composition of steelhead trout tissues may be affected by both cold stress and starvation when the temperature decreased to 2℃, and the change of phospholipid composition of muscle was very obvious.展开更多
Taking Eighteen-Step Ladder in Chongqing Municipality of China for example,physical space forms of street space structure,space hierarchy,street scale,and unit architectural type were elaborated to explore the relatio...Taking Eighteen-Step Ladder in Chongqing Municipality of China for example,physical space forms of street space structure,space hierarchy,street scale,and unit architectural type were elaborated to explore the relation between spatial characteristics and spirit of place of traditional blocks.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 31572634 and 31702364)Shandong Province Key Research and Development Plan (Nos. 2016CYJS04A01 and 2017CX GC0106)
文摘This study was conducted to evaluate the critical thermal maximum(CTMax), the routine metabolism rate(MO_2) and the limiting oxygen saturation(LOS) of three salmonids with four different body weights ranging from 16 g to 131 g. The CTMax was estimated at three different heating rates including 0.5℃ min^(-1), 1℃ h^(-1) and 2℃ d^(-1). Results showed that the CTMax of maple trout(Oncorhynchus mykiss) was the highest, which was followed by steelhead trout(O. mykiss) and Atlantic salmon(Salmon salar). The CTMax of the salmonid fish decreased with the increment of body weight, and was significantly influenced by the heating rate. The MO_2 of the salmonid fish increased with the increment of temperature, and decreased with the increment of body weight. Suffocation points of the fish decreased with increasing body weight and temperature. Steelhead trout was more tolerant to hypoxia than maple trout and Atlantic salmon, while the MO_2 of Atlantic salmon was the highest among these three salmonids. The LOS of the fish generally had a positive trend with temperature and body weight, and the LOS of steelhead trout was significantly lower than that of maple trout and Atlantic salmon. In conclusion, maple trout was the most tolerant kind to high temperature, while steelhead trout was the most tolerant to hypoxia among three kinds of salmonids. Moreover, the abilities to tolerate higher temperature of three salmonids were affected by their body weight and the heating rate, while the abilities to tolerate hypoxia were influenced by their body weight and the water temperature.
基金jointly funded by the National Natural Science Foundation of China (Nos. 31572634 and 31702364)the Fundamental Research Funds for the Central Universities of China (No. 20161205)+1 种基金the Key Research and Development Program of Shandong Province (Nos. 2016CYJS04A01 and 2017CXGC0106)Science and Technology Planning Project of Guangdong Province, China (No. 2017B030314052)
文摘In this study, the changes of the fatty acid composition of phospholipid in different tissues(muscle, heart, brain and spleen) of steelhead trout(Oncorhynchus mykiss) were analyzed when the water temperature decreased gradually from 16 to 12℃℃, 8℃, 6℃, 4℃, 2 and 1℃℃. Three fish individuals each tank(average weight 70.32 g ± 9.12 g) were collected and used to analysis at each designed temperatures. At normal temperature(16℃), the fatty acid composition of phospholipid of muscle and heart was similar each other. The highest concentration of saturate fatty acids(SFA) was found in the phospholipid of spleen. The brain phospholipid contained higher oleic acid(18:1 n9) than the phospholipid of other tissues at 16℃. When the environmental temperature decreased, the concentration of unsaturated fatty acids of phospholipids in all tissues increased, and accordingly the ratio pf the unsaturated to saturated fatty acids(U/S) and unsaturation index(UI) increased, indicating that steelhead trout can compensate temperature-dependent changes in membrane fluidity by remodeling the fatty acid composition of phospholipids. The changes in the fatty acid composition of phospholipid were tissue-specific. At the early stages of the experiment(16 to 8℃℃), the fatty acid composition of phospholipid changed remarkably in muscle, heart, and spleen. When temperature decreased to less than 8℃, an obvious response of phospholipid fatty acid was observed in all tissues. The change of phospholipid composition of steelhead trout tissues may be affected by both cold stress and starvation when the temperature decreased to 2℃, and the change of phospholipid composition of muscle was very obvious.
基金Supported by Special Fund of College of Landscape Architecture,Sichuan Agricultural University
文摘Taking Eighteen-Step Ladder in Chongqing Municipality of China for example,physical space forms of street space structure,space hierarchy,street scale,and unit architectural type were elaborated to explore the relation between spatial characteristics and spirit of place of traditional blocks.
