[Objective] The aim was to discuss the morphological differences of four carp populations.[Method] Based on traditional morphological data（including countable and measurable characters） and framework data,the morpho...[Objective] The aim was to discuss the morphological differences of four carp populations.[Method] Based on traditional morphological data（including countable and measurable characters） and framework data,the morphological differences and phylogenesis of Yellow River carp population（YR）,wild four-naris carp population（WF）,farmed four-naris carp population（FF） and carp population from Suzhou section of Wusong River（WR） were studied by means of multivariate analysis.[Result] There was no significant difference（P〉0.05） in countable characters among four carp populations.Discriminant analysis showed the discriminating accuracy of YR,WF,FF and WR population were 87.5%,78.1%,73.5% and 96.8% respectively,and the synthetic discriminating accuracy of four populations was up to 83.7%.In addition,cluster analysis revealed that YR population and WF population clustered together,while FF population and WR population clustered together.Principal component analysis indicated that the morphological differences among four populations mainly came from the head,tail and vertical axis of fish.[Conclusion] The study could provide theoretical foundations for the purification and rejuvenation of rare four-naris carp.展开更多
For reconstructing a freeform feature from point cloud, a deformation-based method is proposed in this paper. The freeform feature consists of a secondary surface and a blending surface. The secondary surface plays a ...For reconstructing a freeform feature from point cloud, a deformation-based method is proposed in this paper. The freeform feature consists of a secondary surface and a blending surface. The secondary surface plays a role in substituting a local region of a given primary surface. The blending surface acts as a bridge to smoothly connect the unchanged region of the primary surface with the secondary surface. The secondary surface is generated by surface deformation subjected to line constraints, i.e., character lines and limiting lines, not designed by conventional methods. The lines are used to represent the underlying informa-tion of the freeform feature in point cloud, where the character lines depict the feature’s shape, and the limiting lines determine its location and orientation. The configuration of the character lines and the extraction of the limiting lines are discussed in detail. The blending surface is designed by the traditional modeling method, whose intrinsic parameters are recovered from point cloud through a series of steps, namely, point cloud slicing, circle fitting and regression analysis. The proposed method is used not only to effectively and efficiently reconstruct the freeform feature, but also to modify it by manipulating the line constraints. Typical examples are given to verify our method.展开更多
To predict the flow evolution of fish swimming problems,a flow solver based on the immersed boundary lattice Boltzmann method is developed.A flexible iterative algorithm based on the framework of implicit boundary for...To predict the flow evolution of fish swimming problems,a flow solver based on the immersed boundary lattice Boltzmann method is developed.A flexible iterative algorithm based on the framework of implicit boundary force correction is used to save the computational cost and memory,and the momentum forcing is described by a simple direct force formula without complicated integral calculation when the velocity correction at the boundary node is determined.With the presented flow solver,the hydrodynamic interaction between the fish-induced dynamic stall vortices and the incoming vortices in unsteady flow is analyzed.Numerical simulation results unveil the mechanism of fish exploiting vortices to enhance their own hydrodynamic performances.The superior swimming performances originate from the relative movement between the“merged vortex”and the locomotion of the fishtail,which is controlled by the phase difference.Formation conditions of the“merged vortex”become the key factor for fish to exploit vortices to improve their swimming performance.We further discuss the effect of the principal components of locomotion.From the results,we conclude that lateral translation plays a crucial role in propulsion while body undulation in tandem with rotation and head motion reduce the locomotor cost.展开更多
The seasonal fluctuation of the plasmodia ofMyxobolus gibelioiWu et Wang, 1982 in the gill filaments of the allogynogenetic gibel carpCarassius auratus gibelio(Bloch) in a fish pond in Hubei Province of China was inve...The seasonal fluctuation of the plasmodia ofMyxobolus gibelioiWu et Wang, 1982 in the gill filaments of the allogynogenetic gibel carpCarassius auratus gibelio(Bloch) in a fish pond in Hubei Province of China was investigated from August 1999 to July 2000. A total of 445 fish was examined; the overall prevalence of the plasmodium infection in the fish was 64.94% and mean abundance of plasmodia was 11.65 ± 27.85 (mean ± SD). Significant seasonal changes in prevalence and mean abundance, with higher levels of the plasmodia infection from late spring to autumn, were observed.展开更多
The Chaenocephalus aceratus were sampled in summers between 1979 and 1990. Their otoliths show pattern of daily microincrements as otoliths of similar species--Pseudochaenichthys georgianus and fishes both temperate a...The Chaenocephalus aceratus were sampled in summers between 1979 and 1990. Their otoliths show pattern of daily microincrements as otoliths of similar species--Pseudochaenichthys georgianus and fishes both temperate and tropical waters. Changes of the microincrements growth pattern and otolith shape are described in relation to larval, hatching and metamorphosis stages have similar patterns for Ps. georgianus and Charnpsocephalus gunnari, reflecting similar habitats in their early life. Width of larvae-postlarvae daily increments are： （1.0-1.6）×10-3 SSI, （1.8-2.8）×10-3 SG1 and （1.5-2.4）×10-3 ANI. They were search and chosen automatically from density profiles of otolith tissues. Tissues were prepared by new saving time and materials way--one time up to 40 ones per microscopic glass. Age of fish estimated from microincrements was alike to that inferred from the body length distribution, otoliths mass （age （years） = 140.82 OM （g） ＋ 0.8546） and otolith shape changes--large in length and surface on medial plane. Those parameters create age groups of close neighbours. They have different environments. C. aceratus due to its adaptation to cold water, attain rapidly large body according to a growth equation： Lt= 75.1 ×10-3 （1-e-0.26（t-0.51）. Among large fishes there were only females.展开更多
Lately, there has been an increasing interest in intraspeciflc variation in behaviour, and numerous studies on persona- lity have been performed in a variety of animals, including several fish species. Individuals hav...Lately, there has been an increasing interest in intraspeciflc variation in behaviour, and numerous studies on persona- lity have been performed in a variety of animals, including several fish species. Individuals have been divided into coping style categories or arranged along a behaviour gradient, such as the bold/shy continuum. However, many fish species live in groups, and the social environment can influence the behaviour of an animal in different ways. There may be conflicts within groups due to competition for resources, and dominance hierarchies are commonly found. On the other hand, there are many benefits of con- sensus decision-making within the group. Conformity of behaviour is probably adaptive, due to the benefit of public information on, for example, food resources and predation risk. Accordingly, studies of fish shoals have found evidence of consensus deci- sion-making. Furthermore, factors in the environment, such as predation risk would also influence the behaviour expressed. To be able to understand behaviour patterns in a group of fish, it is necessary to consider the variation of individual characteristics, and how the group, as well as other environmental factors, affects the behaviour of individuals. Here, I will review studies on different aspects of personality within a social context in fish, with a special emphasis on the Eurasian perch Percafluviatilis [Current Zo- ology 58 （1）： 35-44, 2012].展开更多
基金Supported by Open Fund of Key Laboratory of Ecological Environment and Resources of Inland Fisheries,Chinese Academy of Fishery SciencesThree Projects for Fishery of Jiangsu Province(K2008-3)~~
文摘[Objective] The aim was to discuss the morphological differences of four carp populations.[Method] Based on traditional morphological data（including countable and measurable characters） and framework data,the morphological differences and phylogenesis of Yellow River carp population（YR）,wild four-naris carp population（WF）,farmed four-naris carp population（FF） and carp population from Suzhou section of Wusong River（WR） were studied by means of multivariate analysis.[Result] There was no significant difference（P〉0.05） in countable characters among four carp populations.Discriminant analysis showed the discriminating accuracy of YR,WF,FF and WR population were 87.5%,78.1%,73.5% and 96.8% respectively,and the synthetic discriminating accuracy of four populations was up to 83.7%.In addition,cluster analysis revealed that YR population and WF population clustered together,while FF population and WR population clustered together.Principal component analysis indicated that the morphological differences among four populations mainly came from the head,tail and vertical axis of fish.[Conclusion] The study could provide theoretical foundations for the purification and rejuvenation of rare four-naris carp.
基金the National Natural Science Foundation of China (No. 50575098)China Postdoctoral Science Foundation
文摘For reconstructing a freeform feature from point cloud, a deformation-based method is proposed in this paper. The freeform feature consists of a secondary surface and a blending surface. The secondary surface plays a role in substituting a local region of a given primary surface. The blending surface acts as a bridge to smoothly connect the unchanged region of the primary surface with the secondary surface. The secondary surface is generated by surface deformation subjected to line constraints, i.e., character lines and limiting lines, not designed by conventional methods. The lines are used to represent the underlying informa-tion of the freeform feature in point cloud, where the character lines depict the feature’s shape, and the limiting lines determine its location and orientation. The configuration of the character lines and the extraction of the limiting lines are discussed in detail. The blending surface is designed by the traditional modeling method, whose intrinsic parameters are recovered from point cloud through a series of steps, namely, point cloud slicing, circle fitting and regression analysis. The proposed method is used not only to effectively and efficiently reconstruct the freeform feature, but also to modify it by manipulating the line constraints. Typical examples are given to verify our method.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘To predict the flow evolution of fish swimming problems,a flow solver based on the immersed boundary lattice Boltzmann method is developed.A flexible iterative algorithm based on the framework of implicit boundary force correction is used to save the computational cost and memory,and the momentum forcing is described by a simple direct force formula without complicated integral calculation when the velocity correction at the boundary node is determined.With the presented flow solver,the hydrodynamic interaction between the fish-induced dynamic stall vortices and the incoming vortices in unsteady flow is analyzed.Numerical simulation results unveil the mechanism of fish exploiting vortices to enhance their own hydrodynamic performances.The superior swimming performances originate from the relative movement between the“merged vortex”and the locomotion of the fishtail,which is controlled by the phase difference.Formation conditions of the“merged vortex”become the key factor for fish to exploit vortices to improve their swimming performance.We further discuss the effect of the principal components of locomotion.From the results,we conclude that lateral translation plays a crucial role in propulsion while body undulation in tandem with rotation and head motion reduce the locomotor cost.
文摘The seasonal fluctuation of the plasmodia ofMyxobolus gibelioiWu et Wang, 1982 in the gill filaments of the allogynogenetic gibel carpCarassius auratus gibelio(Bloch) in a fish pond in Hubei Province of China was investigated from August 1999 to July 2000. A total of 445 fish was examined; the overall prevalence of the plasmodium infection in the fish was 64.94% and mean abundance of plasmodia was 11.65 ± 27.85 (mean ± SD). Significant seasonal changes in prevalence and mean abundance, with higher levels of the plasmodia infection from late spring to autumn, were observed.
文摘The Chaenocephalus aceratus were sampled in summers between 1979 and 1990. Their otoliths show pattern of daily microincrements as otoliths of similar species--Pseudochaenichthys georgianus and fishes both temperate and tropical waters. Changes of the microincrements growth pattern and otolith shape are described in relation to larval, hatching and metamorphosis stages have similar patterns for Ps. georgianus and Charnpsocephalus gunnari, reflecting similar habitats in their early life. Width of larvae-postlarvae daily increments are： （1.0-1.6）×10-3 SSI, （1.8-2.8）×10-3 SG1 and （1.5-2.4）×10-3 ANI. They were search and chosen automatically from density profiles of otolith tissues. Tissues were prepared by new saving time and materials way--one time up to 40 ones per microscopic glass. Age of fish estimated from microincrements was alike to that inferred from the body length distribution, otoliths mass （age （years） = 140.82 OM （g） ＋ 0.8546） and otolith shape changes--large in length and surface on medial plane. Those parameters create age groups of close neighbours. They have different environments. C. aceratus due to its adaptation to cold water, attain rapidly large body according to a growth equation： Lt= 75.1 ×10-3 （1-e-0.26（t-0.51）. Among large fishes there were only females.
文摘Lately, there has been an increasing interest in intraspeciflc variation in behaviour, and numerous studies on persona- lity have been performed in a variety of animals, including several fish species. Individuals have been divided into coping style categories or arranged along a behaviour gradient, such as the bold/shy continuum. However, many fish species live in groups, and the social environment can influence the behaviour of an animal in different ways. There may be conflicts within groups due to competition for resources, and dominance hierarchies are commonly found. On the other hand, there are many benefits of con- sensus decision-making within the group. Conformity of behaviour is probably adaptive, due to the benefit of public information on, for example, food resources and predation risk. Accordingly, studies of fish shoals have found evidence of consensus deci- sion-making. Furthermore, factors in the environment, such as predation risk would also influence the behaviour expressed. To be able to understand behaviour patterns in a group of fish, it is necessary to consider the variation of individual characteristics, and how the group, as well as other environmental factors, affects the behaviour of individuals. Here, I will review studies on different aspects of personality within a social context in fish, with a special emphasis on the Eurasian perch Percafluviatilis [Current Zo- ology 58 （1）： 35-44, 2012].
