Co-occurrence pattern of fish species plays an important role in understanding the spatio-temporal structure and the stability of fish community.Species coexistence may vary with time and space.The co-occurrence patte...Co-occurrence pattern of fish species plays an important role in understanding the spatio-temporal structure and the stability of fish community.Species coexistence may vary with time and space.The co-occurrence patterns of fish species were examined using the C-score under fixed-fixed null model for fish communities in spring and autumn over different years in the Haizhou Bay,China.The results showed that fish assemblages in the whole bay had non-random patterns in spring and autumn over different years.However,the fish co-occurrence patterns were different for the northern and southern fish assemblages in spring and autumn.The northern fish assemblage showed structured pattern,whereas the southern assemblage were randomly assembled in spring.The co-occurrence patterns of fish communities were relatively stable over different years,and the number of significant species pairs in northern assemblage was more than that in the southern assemblage.Environmental heterogeneity played an important role in determining the distributions of fish species that formed significant species pairs,which might affect the co-occurrence patterns of northern and southern assemblages further in the Haizhou Bay.展开更多
Each type of fishery has its own characteristic behavior, and understanding this condition is an important part of devel- oping and managing fishing operations comprehensively. Based on the random walk model, the rela...Each type of fishery has its own characteristic behavior, and understanding this condition is an important part of devel- oping and managing fishing operations comprehensively. Based on the random walk model, the relationship between distance and frequency distribution of adjacent fishing positions was analyzed by the Commission for Conservation of Antarctic Marine Living Resources (CCAMLR) Subareas 48.1, 48.2, and 48.3. The frequency of distances between consecutive hauls demonstrated a heavy- tailed distribution, which could be used to estimate the value of parameter μ in the power function F(l)~ l μ of a random walk model to determine the type of random walk patterns that characterize Chinese krill fishery. Results indicated that the fishing pattern of the Chinese krill fishery is consistent with the Lévy random walk model, with which the step-length is applied to analyze the walking pattern. When a defined walk in a space of dimension is greater than one, the steps made are in isotropic random directions. Fur- thermore, a strong and positive correlation between fishing behavior (using the parameter μ as an indicator) and catch per unit effort of the Chinese krill fishery was observed.展开更多
Human food consists of 2 major parts: plants and animals. Primitive people collected food by fishing,hunting and gathering,and later they developed primitive agriculture and animal husbandry about near to 10 thousand ...Human food consists of 2 major parts: plants and animals. Primitive people collected food by fishing,hunting and gathering,and later they developed primitive agriculture and animal husbandry about near to 10 thousand years ago. Due to different natural conditions,the distribution of plants,wild animals which were suitable for domestication are unbalanced in the world; therefore species of domesticated crops and animals vary throughout the world,which leads to the differences in the food patterns of human society. The Great Discovery of Geography ushered in the ear of exchanges among people,one of which is the exchange in agriculture. Crops from America were introduced to the old continent while poultry and livestock of the old continent were also brought to America; later,domesticated crops and animals were spread to the newly-discovered Oceania. Since then,the differences in people's food pattern have begun to narrowdown and started on the path to convergence,and the whole process is basically a saddle-shaped development.展开更多
A bionic neural network for fish-robot locomotion is presented. The bionic neural network inspired from fish neural net- work consists of one high level controller and one chain of central pattern generators （CPGs）....A bionic neural network for fish-robot locomotion is presented. The bionic neural network inspired from fish neural net- work consists of one high level controller and one chain of central pattern generators （CPGs）. Each CPG contains a nonlinear neural Zhang oscillator which shows properties similar to sine-cosine model. Simulation re, suits show that the bionic neural network presents a good performance in controlling the fish-robot to execute various motions such as startup, stop, forward swimming, backward swimming, turn right and turn left.展开更多
基金funded by the National Natural Science Foundation of China (No. 31772852)the Fundamental Research Funds for the Central Universities (Nos. 2015 62030, 201612004)the Public Science and Technology Research Funds Projects of Ocean (No. 201305030)
文摘Co-occurrence pattern of fish species plays an important role in understanding the spatio-temporal structure and the stability of fish community.Species coexistence may vary with time and space.The co-occurrence patterns of fish species were examined using the C-score under fixed-fixed null model for fish communities in spring and autumn over different years in the Haizhou Bay,China.The results showed that fish assemblages in the whole bay had non-random patterns in spring and autumn over different years.However,the fish co-occurrence patterns were different for the northern and southern fish assemblages in spring and autumn.The northern fish assemblage showed structured pattern,whereas the southern assemblage were randomly assembled in spring.The co-occurrence patterns of fish communities were relatively stable over different years,and the number of significant species pairs in northern assemblage was more than that in the southern assemblage.Environmental heterogeneity played an important role in determining the distributions of fish species that formed significant species pairs,which might affect the co-occurrence patterns of northern and southern assemblages further in the Haizhou Bay.
基金sponsored partly by the National Key R&D Program of China (No. 2018YFC1406801)the National Natural Science Foundation of China (No. 41776185)the Key Course Construction Program of the Shanghai Municipal Education Commission (Biological Oceanography) (No. A1-0201-00-1204)
文摘Each type of fishery has its own characteristic behavior, and understanding this condition is an important part of devel- oping and managing fishing operations comprehensively. Based on the random walk model, the relationship between distance and frequency distribution of adjacent fishing positions was analyzed by the Commission for Conservation of Antarctic Marine Living Resources (CCAMLR) Subareas 48.1, 48.2, and 48.3. The frequency of distances between consecutive hauls demonstrated a heavy- tailed distribution, which could be used to estimate the value of parameter μ in the power function F(l)~ l μ of a random walk model to determine the type of random walk patterns that characterize Chinese krill fishery. Results indicated that the fishing pattern of the Chinese krill fishery is consistent with the Lévy random walk model, with which the step-length is applied to analyze the walking pattern. When a defined walk in a space of dimension is greater than one, the steps made are in isotropic random directions. Fur- thermore, a strong and positive correlation between fishing behavior (using the parameter μ as an indicator) and catch per unit effort of the Chinese krill fishery was observed.
文摘Human food consists of 2 major parts: plants and animals. Primitive people collected food by fishing,hunting and gathering,and later they developed primitive agriculture and animal husbandry about near to 10 thousand years ago. Due to different natural conditions,the distribution of plants,wild animals which were suitable for domestication are unbalanced in the world; therefore species of domesticated crops and animals vary throughout the world,which leads to the differences in the food patterns of human society. The Great Discovery of Geography ushered in the ear of exchanges among people,one of which is the exchange in agriculture. Crops from America were introduced to the old continent while poultry and livestock of the old continent were also brought to America; later,domesticated crops and animals were spread to the newly-discovered Oceania. Since then,the differences in people's food pattern have begun to narrowdown and started on the path to convergence,and the whole process is basically a saddle-shaped development.
文摘A bionic neural network for fish-robot locomotion is presented. The bionic neural network inspired from fish neural net- work consists of one high level controller and one chain of central pattern generators （CPGs）. Each CPG contains a nonlinear neural Zhang oscillator which shows properties similar to sine-cosine model. Simulation re, suits show that the bionic neural network presents a good performance in controlling the fish-robot to execute various motions such as startup, stop, forward swimming, backward swimming, turn right and turn left.
