Pakistani marine waters are under an open access regime. Due to poor management and policy implications, blind fishing is continued which may result in ecological as well as economic losses. Thus, it is of utmost impo...Pakistani marine waters are under an open access regime. Due to poor management and policy implications, blind fishing is continued which may result in ecological as well as economic losses. Thus, it is of utmost importance to estimate fishery resources before harvesting. In this study, catch and effort data, 1996-2009, of Kiddi shrimp Parapenaeopsis stylifera fishery from Pakistani marine waters was analyzed by using specialized fishery software in order to know fishery stock status of this commercially important shrimp. Maximum, minimum and average capture production ofP. stylifera was observed as 15 912 metric tons （mr） （1997）, 9 438 mt （2009） and 11 667 mt/a. Two stock assessment tools viz. CEDA （catch and effort data analysis） and ASPIC （a stock production model incorporating covariates） were used to compute MSY （maximum sustainable yield） of this organism. In CEDA, three surplus production models, Fox, Schaefer and Pella-Tomlinson, along with three error assumptions, log, log normal and gamma, were used. For initial proportion （IP） 0.8, the Fox model computed MSY as 6 858 nat （CV=0.204, R^2=0.709） and 7 384 mt （CV=0.149, R^2=0.72） for log and log normal error assumption respectively. Here, gamma error produced minimization failure. Estimated MSY by using Schaefer and Pella-Tomlinson models remained the same for log, log normal and gamma error assumptions i.e. 7 083 mt, 8 209 mt and 7 242 mt correspondingly. The Schafer results showed highest goodness of fit R2 （0.712） values. ASPIC computed MSY, CV, R2, FMsv and BMsv parameters for the Fox model as 7 219 nat, 0.142, 0.872, 0.111 and 65 280, while for the Logistic model the computed values remained 7 720 mt, 0.148, 0.868, 0.107 and 72 110 correspondingly. Results obtained have shown that P. stylifera has been overexploited. Immediate steps are needed to conserve this fishery resource for the future and research on other species of commercial importance is urgently needed.展开更多
This study records length-weight relationships （LWRs） for eleven commercially important marine catfish species of the family Ariidae （sea catfishes） and Plotosidae （eel catfishes） from the northern Arabian Sea c...This study records length-weight relationships （LWRs） for eleven commercially important marine catfish species of the family Ariidae （sea catfishes） and Plotosidae （eel catfishes） from the northern Arabian Sea coast of Pakistan. The specimens were sampled from December 2014 to November 2015, using bottom trawls with various mesh sizes by commercial vessels. The species were Nemapteryx caelatus, Sciades sona, Arius gagora, Batrachocephalus mino, Neturna thalassina, N. bilineata, Osteogeneiosus militaris, Plicofollis dussumieri, P. tenuispinis, Plotosus limbatus, and P. lineatus. Of the eleven species, two species A. gagora and N. bilineata were recorded for the first time and LWRs for four species A. gagora, N. bilineata, S. sona, and B. mino still have no data in the FishBase database. In addition, new maximum length for each of the three species N. bilineata, O. militaris andB. mino was also found.展开更多
Morphotaxonomy and seasonal abundance of dinoflagellates of the genera Prorocentrum and Mesoporos （Prorocentrales） were studied from nutrient-rich waters, Karachi Harbor and the mouth of the Manora Channel, Pakistan...Morphotaxonomy and seasonal abundance of dinoflagellates of the genera Prorocentrum and Mesoporos （Prorocentrales） were studied from nutrient-rich waters, Karachi Harbor and the mouth of the Manora Channel, Pakistan during May 2002-July 2003. Using both light and scanning electron microscopy, 13 species of Prorocentrales were identified according to cell shape, size, ornamentation of thecal plates, and architecture of apical platelets, apical pore area, marginal pores, and intercalary bands. P. sigmoides, P. arcuatum, P. scutellum, P. donghaiense, P. balticum, P. minimum, P. emarginatum, P. lima, P. faustiae, and Mesoporos perforatus constitute new records for sindh coast of Pakistan. The most abundant species were P. minimum/P, balticum （4.5x103 cells/L）, P. micans （1.1~103 cells/L）, P. gracile/P, sigmoides （2.5 x 102 cells/L） and P. donghaiense （6.6 x 103 cells/L） at temperatures of 29-31 ~C and salinities of 35-40. Maximum abundance was observed in winter and lower abundance in summer. There was no significant change in the distribution of species between stations except for the benthic species which occurred close to Karachi Harbor waters. Significant positive correlations were observed between Prorocentrum spp. and temperature （R2=0.27） and negative correlations with salinity （R2=-0.32） except for P. minimum and P. emarginatum which has negative correlation with temperature （R2=-0.24） and positive with salinity （R2=0.08, 0.19）. The finding of potential okadaic-acid producing species of benthic Prorocentrum call for monitoring for possible human health problems in this region.展开更多
It is argued that it has not yet been able to value the historical, philosophical and epistemological travail, represented by the filth and fourth centuries BC of the ancient Greek world, which preceded the highest sc...It is argued that it has not yet been able to value the historical, philosophical and epistemological travail, represented by the filth and fourth centuries BC of the ancient Greek world, which preceded the highest scientific heritage, represented by the so-called golden age of Euclid, Archimedes and Apollonius, Ⅲ-Ⅱ century BC. Well, it is believed that with our complex concept of tradition of thought within which we insert not only epistemological concepts but also philosophical principles, historical and social frameworks, in stasis or in strong movement, processed by us, it is possible better interpret that happy moment of scientific constructions of the third and second century BC, as a result of the valorization of the deep travail and serious battle that preceded it between the fourth and fifth century BC. It is investigated in particular in our paper the development of astronomical thought between the fifth and fourth centuries BC, in the ancient Greek thought, and at last a particular presumed criticism by Archimedes in his Sandreckoner to Aristarchus.展开更多
Four-nation meetings advance the peace process in Afghanistan A meeting involving representatives from Afghanistan,Pakistan,China and the United States held on January 11 in Islamabad,Pakistan,established the Quadrila...Four-nation meetings advance the peace process in Afghanistan A meeting involving representatives from Afghanistan,Pakistan,China and the United States held on January 11 in Islamabad,Pakistan,established the Quadrilateral Coordination Group(QCG)to further the peace process in Afghanistan.展开更多
Body size is a highly variable trait among geographically separated populations. Size-assortative reproductive isolation has been linked to recent adaptive radiations of threespine stickleback （Gasterosteus aculeatus...Body size is a highly variable trait among geographically separated populations. Size-assortative reproductive isolation has been linked to recent adaptive radiations of threespine stickleback （Gasterosteus aculeatus） into freshwater, but the genetic basis of the commonly found size differ- ence between anadromous and derived lacustrine sticklebacks has not been tested. We studied the genetic basis of size differences between recently diverging stickleback lineages in southwest Alaska using a common environment experiment. We crossed stickleback within one anadromous （Naknek River） and one lake （Pringle Lake） population and between the anadromous and two lake populations （Pringle and JoJo Lakes）, and raised them in a salinity of 4-6 ppt. The F1 anadromous and freshwater forms differed significantly in size, whereas hybrids were intermediate or exhibited dominance toward the anadromous form. Additionally, the size of freshwater Fls differed from their wild counterparts, with within-population Fls from Pringle Lake growing larger than their wild counterparts, while there was no size difference between lab-raised and wild anadromous fish. Sexual dimorphism was always present in anadromous fish, but not in freshwater, and not always in the hybrid crosses. These results, along with parallel changes among anadromous and fresh- water forms in other regions, suggest that this heritable trait is both plastic and may be under di- vergent and/or sexual selection.展开更多
The Wakhan Corridor is surrounded by the Mackinder＇s Heart Land. Located at the cross roads of four countries： Main land Afghanistan, Tajikistan, China, and Pakistan. The Wakhan Corridor has been the most important ...The Wakhan Corridor is surrounded by the Mackinder＇s Heart Land. Located at the cross roads of four countries： Main land Afghanistan, Tajikistan, China, and Pakistan. The Wakhan Corridor has been the most important junction point of the Silk Route since its inception. The corridor has long been used as a trade route by Europeans and Chinese to reach the Indian Plains and the Indian Ocean＇s Sea Lines of Communications through the Arabian Sea Coasts. Extra regional aspects in forms of quest for the Great Game between Russia and Britain since 1838, the Chinese Communist Revolution of 1949, the Soviet Invasion of Afghanistan for a decade followed by the NATO invasion of Afghanistan since 2001 has unfortunately kept any kind of infrastructural development in Wakhan as a fallacy. The opening up of Wakhjir Pass by China will surely improve regional trade and relations; however, India feels threatened as it thinks that the opening up of the Wakhan Corridor will be an outflanking maneuvre against its interests in Indianheld Kashmir; however, it cannot remain aloof of other regional and extra regional players and will be forced to share Central Asian energy resources for its economic development along with countries under the U.S. umbrella. The U.S. in combination with China must play its role for enhancing regional stability.展开更多
基金Supported by the Earmarked Fund for Modern Agro-Industry Technology Research System of Chinathe Special Research Fund of Ocean University of China(No.201022001)
文摘Pakistani marine waters are under an open access regime. Due to poor management and policy implications, blind fishing is continued which may result in ecological as well as economic losses. Thus, it is of utmost importance to estimate fishery resources before harvesting. In this study, catch and effort data, 1996-2009, of Kiddi shrimp Parapenaeopsis stylifera fishery from Pakistani marine waters was analyzed by using specialized fishery software in order to know fishery stock status of this commercially important shrimp. Maximum, minimum and average capture production ofP. stylifera was observed as 15 912 metric tons （mr） （1997）, 9 438 mt （2009） and 11 667 mt/a. Two stock assessment tools viz. CEDA （catch and effort data analysis） and ASPIC （a stock production model incorporating covariates） were used to compute MSY （maximum sustainable yield） of this organism. In CEDA, three surplus production models, Fox, Schaefer and Pella-Tomlinson, along with three error assumptions, log, log normal and gamma, were used. For initial proportion （IP） 0.8, the Fox model computed MSY as 6 858 nat （CV=0.204, R^2=0.709） and 7 384 mt （CV=0.149, R^2=0.72） for log and log normal error assumption respectively. Here, gamma error produced minimization failure. Estimated MSY by using Schaefer and Pella-Tomlinson models remained the same for log, log normal and gamma error assumptions i.e. 7 083 mt, 8 209 mt and 7 242 mt correspondingly. The Schafer results showed highest goodness of fit R2 （0.712） values. ASPIC computed MSY, CV, R2, FMsv and BMsv parameters for the Fox model as 7 219 nat, 0.142, 0.872, 0.111 and 65 280, while for the Logistic model the computed values remained 7 720 mt, 0.148, 0.868, 0.107 and 72 110 correspondingly. Results obtained have shown that P. stylifera has been overexploited. Immediate steps are needed to conserve this fishery resource for the future and research on other species of commercial importance is urgently needed.
文摘This study records length-weight relationships （LWRs） for eleven commercially important marine catfish species of the family Ariidae （sea catfishes） and Plotosidae （eel catfishes） from the northern Arabian Sea coast of Pakistan. The specimens were sampled from December 2014 to November 2015, using bottom trawls with various mesh sizes by commercial vessels. The species were Nemapteryx caelatus, Sciades sona, Arius gagora, Batrachocephalus mino, Neturna thalassina, N. bilineata, Osteogeneiosus militaris, Plicofollis dussumieri, P. tenuispinis, Plotosus limbatus, and P. lineatus. Of the eleven species, two species A. gagora and N. bilineata were recorded for the first time and LWRs for four species A. gagora, N. bilineata, S. sona, and B. mino still have no data in the FishBase database. In addition, new maximum length for each of the three species N. bilineata, O. militaris andB. mino was also found.
基金Supported by Scholarship (IRSIP) of Higher Education Commission,Islamabad,Pakistan for Doctoral student Miss.Sonia Munir
文摘Morphotaxonomy and seasonal abundance of dinoflagellates of the genera Prorocentrum and Mesoporos （Prorocentrales） were studied from nutrient-rich waters, Karachi Harbor and the mouth of the Manora Channel, Pakistan during May 2002-July 2003. Using both light and scanning electron microscopy, 13 species of Prorocentrales were identified according to cell shape, size, ornamentation of thecal plates, and architecture of apical platelets, apical pore area, marginal pores, and intercalary bands. P. sigmoides, P. arcuatum, P. scutellum, P. donghaiense, P. balticum, P. minimum, P. emarginatum, P. lima, P. faustiae, and Mesoporos perforatus constitute new records for sindh coast of Pakistan. The most abundant species were P. minimum/P, balticum （4.5x103 cells/L）, P. micans （1.1~103 cells/L）, P. gracile/P, sigmoides （2.5 x 102 cells/L） and P. donghaiense （6.6 x 103 cells/L） at temperatures of 29-31 ~C and salinities of 35-40. Maximum abundance was observed in winter and lower abundance in summer. There was no significant change in the distribution of species between stations except for the benthic species which occurred close to Karachi Harbor waters. Significant positive correlations were observed between Prorocentrum spp. and temperature （R2=0.27） and negative correlations with salinity （R2=-0.32） except for P. minimum and P. emarginatum which has negative correlation with temperature （R2=-0.24） and positive with salinity （R2=0.08, 0.19）. The finding of potential okadaic-acid producing species of benthic Prorocentrum call for monitoring for possible human health problems in this region.
文摘It is argued that it has not yet been able to value the historical, philosophical and epistemological travail, represented by the filth and fourth centuries BC of the ancient Greek world, which preceded the highest scientific heritage, represented by the so-called golden age of Euclid, Archimedes and Apollonius, Ⅲ-Ⅱ century BC. Well, it is believed that with our complex concept of tradition of thought within which we insert not only epistemological concepts but also philosophical principles, historical and social frameworks, in stasis or in strong movement, processed by us, it is possible better interpret that happy moment of scientific constructions of the third and second century BC, as a result of the valorization of the deep travail and serious battle that preceded it between the fourth and fifth century BC. It is investigated in particular in our paper the development of astronomical thought between the fifth and fourth centuries BC, in the ancient Greek thought, and at last a particular presumed criticism by Archimedes in his Sandreckoner to Aristarchus.
文摘Four-nation meetings advance the peace process in Afghanistan A meeting involving representatives from Afghanistan,Pakistan,China and the United States held on January 11 in Islamabad,Pakistan,established the Quadrilateral Coordination Group(QCG)to further the peace process in Afghanistan.
文摘Body size is a highly variable trait among geographically separated populations. Size-assortative reproductive isolation has been linked to recent adaptive radiations of threespine stickleback （Gasterosteus aculeatus） into freshwater, but the genetic basis of the commonly found size differ- ence between anadromous and derived lacustrine sticklebacks has not been tested. We studied the genetic basis of size differences between recently diverging stickleback lineages in southwest Alaska using a common environment experiment. We crossed stickleback within one anadromous （Naknek River） and one lake （Pringle Lake） population and between the anadromous and two lake populations （Pringle and JoJo Lakes）, and raised them in a salinity of 4-6 ppt. The F1 anadromous and freshwater forms differed significantly in size, whereas hybrids were intermediate or exhibited dominance toward the anadromous form. Additionally, the size of freshwater Fls differed from their wild counterparts, with within-population Fls from Pringle Lake growing larger than their wild counterparts, while there was no size difference between lab-raised and wild anadromous fish. Sexual dimorphism was always present in anadromous fish, but not in freshwater, and not always in the hybrid crosses. These results, along with parallel changes among anadromous and fresh- water forms in other regions, suggest that this heritable trait is both plastic and may be under di- vergent and/or sexual selection.
文摘The Wakhan Corridor is surrounded by the Mackinder＇s Heart Land. Located at the cross roads of four countries： Main land Afghanistan, Tajikistan, China, and Pakistan. The Wakhan Corridor has been the most important junction point of the Silk Route since its inception. The corridor has long been used as a trade route by Europeans and Chinese to reach the Indian Plains and the Indian Ocean＇s Sea Lines of Communications through the Arabian Sea Coasts. Extra regional aspects in forms of quest for the Great Game between Russia and Britain since 1838, the Chinese Communist Revolution of 1949, the Soviet Invasion of Afghanistan for a decade followed by the NATO invasion of Afghanistan since 2001 has unfortunately kept any kind of infrastructural development in Wakhan as a fallacy. The opening up of Wakhjir Pass by China will surely improve regional trade and relations; however, India feels threatened as it thinks that the opening up of the Wakhan Corridor will be an outflanking maneuvre against its interests in Indianheld Kashmir; however, it cannot remain aloof of other regional and extra regional players and will be forced to share Central Asian energy resources for its economic development along with countries under the U.S. umbrella. The U.S. in combination with China must play its role for enhancing regional stability.
