Different culture methods may affect the intensive culture system of Pacific white shrimp(Litopenaeus vannamei) regarding water quality and growth and economic performance.This study evaluated the potential effects of...Different culture methods may affect the intensive culture system of Pacific white shrimp(Litopenaeus vannamei) regarding water quality and growth and economic performance.This study evaluated the potential effects of three culture methods through cultivation of juvenile shrimps under consistent tank management conditions for 84 d.The three methods involved shrimp cultivation in different tanks,i.e.,outdoor tanks with cement bottom(mode-C),greenhouse tanks with cement bottom(mode-G) and outdoor tanks with mud-substrate(mode-M).Results showed that water temperature was significantly higher in mode-G than that in mode-C(P < 0.05).In contrast to the other two treatments,mode-M had stable pH after 50 d cultivation of shrimps.In the mid-late period,the average concentrations of TAN,NO2-N,DIP and COD were significantly lower in mode-M and mode-G compared with those in mode-C(P < 0.05).Despite lack of differences in the final shrimp weight among different treatments(P > 0.05),mode-M had significantly higher shrimp yield,survival rate and feed conversion rate(P < 0.05) than other modes.There were significant differences in revenue and net return among different treatments(P < 0.05).These demonstrated that the treatments of mode-G and mode-M were conductive to the intensive culture system of L.vannamei.展开更多
Marsupenaeusjaponicus Bate is one of the most valuable cultured shrimp species in China and outdoor earthen pond farming is the most common method of culturing this organism. The need to increase soil usage efficiency...Marsupenaeusjaponicus Bate is one of the most valuable cultured shrimp species in China and outdoor earthen pond farming is the most common method of culturing this organism. The need to increase soil usage efficiency in aquaculture has been recognized and a great deal of research effort has been directed toward development of super-intensive farming systems. However, current research and development in this field is largely devoted to Litopenaeus vannamei Boone, while to M.japonicus Bate it has been neglected. In this study, a layered fanning system was designed and a 66-day study was conducted in M.japonicus Bate culture. The system comprised bracket and sand layers that divided a shrimp tank filled to a depth of 1.2 m into four water layers. Conventional tank culture （unlayered） was used as a control. The results show that survival rate, feed conversion efficiency and production of M.japonicus Bate in the layered farming system were 68%, 18%, and 0.59 kg/m^2, respectively, all of which are significantly higher than in the unlayered fanning system （P〈0.01）. These findings confirmed the possibility of using a layered system to culture M. japonicus Bate.展开更多
The present article is an analysis of the innovation system dynamics of the shrimp farming industry in Northeastern Brazil along with the forms of interaction and exchange of information and know-how and the generatio...The present article is an analysis of the innovation system dynamics of the shrimp farming industry in Northeastern Brazil along with the forms of interaction and exchange of information and know-how and the generation and diffusion of innovation characterizing its development. Brazil is the world＇s tenth-largest shrimp producer, with farms strongly concentrated in the Northeastern part of the country. Our findings show that the shrimp production/innovation system in Northeastern Brazil is highly institutionalized and is regulated, controlled and inspected by government agencies. In addition, the sector is now strongly networked with public universities, training and research institutions and other entities with varying degrees of autonomy and different forms of cooperation and integration. Parts of the technological innovations adopted by large companies in the sector are a spin-off of activities at universities and research centers. However, the close cooperation between public research/teaching institutions and large-scale producers is rarely extended to small and midsize businesses, whose interrelations become very fragile. The lack of communication between small producers and public research/teaching institutions makes it more difficult for farmers to assimilate new processes and to generate and incorporate innovations, compromising the dynamics of the production/innovation system of the shrimp farming industry in Northeastern Brazil.展开更多
基金supported by the National Key Technologies R&D Program of China(2007BAD43B06)the Ocean University of China,R&D Institute of Zhejiang,and Zhejiang Ocean University
文摘Different culture methods may affect the intensive culture system of Pacific white shrimp(Litopenaeus vannamei) regarding water quality and growth and economic performance.This study evaluated the potential effects of three culture methods through cultivation of juvenile shrimps under consistent tank management conditions for 84 d.The three methods involved shrimp cultivation in different tanks,i.e.,outdoor tanks with cement bottom(mode-C),greenhouse tanks with cement bottom(mode-G) and outdoor tanks with mud-substrate(mode-M).Results showed that water temperature was significantly higher in mode-G than that in mode-C(P < 0.05).In contrast to the other two treatments,mode-M had stable pH after 50 d cultivation of shrimps.In the mid-late period,the average concentrations of TAN,NO2-N,DIP and COD were significantly lower in mode-M and mode-G compared with those in mode-C(P < 0.05).Despite lack of differences in the final shrimp weight among different treatments(P > 0.05),mode-M had significantly higher shrimp yield,survival rate and feed conversion rate(P < 0.05) than other modes.There were significant differences in revenue and net return among different treatments(P < 0.05).These demonstrated that the treatments of mode-G and mode-M were conductive to the intensive culture system of L.vannamei.
基金Supported by the Science and Technology Plan of Qingdao(No.103-4-5-6-jch)the National Natural Science Foundation of China(No.31101916)+1 种基金the Natural Science Foundation of Shandong Province,China(No.ZR2010CM060)the University Student Innovation Plan of Qingdao Agricultural University(No.201030)
文摘Marsupenaeusjaponicus Bate is one of the most valuable cultured shrimp species in China and outdoor earthen pond farming is the most common method of culturing this organism. The need to increase soil usage efficiency in aquaculture has been recognized and a great deal of research effort has been directed toward development of super-intensive farming systems. However, current research and development in this field is largely devoted to Litopenaeus vannamei Boone, while to M.japonicus Bate it has been neglected. In this study, a layered fanning system was designed and a 66-day study was conducted in M.japonicus Bate culture. The system comprised bracket and sand layers that divided a shrimp tank filled to a depth of 1.2 m into four water layers. Conventional tank culture （unlayered） was used as a control. The results show that survival rate, feed conversion efficiency and production of M.japonicus Bate in the layered farming system were 68%, 18%, and 0.59 kg/m^2, respectively, all of which are significantly higher than in the unlayered fanning system （P〈0.01）. These findings confirmed the possibility of using a layered system to culture M. japonicus Bate.
文摘The present article is an analysis of the innovation system dynamics of the shrimp farming industry in Northeastern Brazil along with the forms of interaction and exchange of information and know-how and the generation and diffusion of innovation characterizing its development. Brazil is the world＇s tenth-largest shrimp producer, with farms strongly concentrated in the Northeastern part of the country. Our findings show that the shrimp production/innovation system in Northeastern Brazil is highly institutionalized and is regulated, controlled and inspected by government agencies. In addition, the sector is now strongly networked with public universities, training and research institutions and other entities with varying degrees of autonomy and different forms of cooperation and integration. Parts of the technological innovations adopted by large companies in the sector are a spin-off of activities at universities and research centers. However, the close cooperation between public research/teaching institutions and large-scale producers is rarely extended to small and midsize businesses, whose interrelations become very fragile. The lack of communication between small producers and public research/teaching institutions makes it more difficult for farmers to assimilate new processes and to generate and incorporate innovations, compromising the dynamics of the production/innovation system of the shrimp farming industry in Northeastern Brazil.
