During July-November in 2003, pelagic fish survey was conducted by longliner covering areas of 03°S-17°S , 96°W-146°W. Sampling gear was longline fishing. With the precaudal length increment, the t...During July-November in 2003, pelagic fish survey was conducted by longliner covering areas of 03°S-17°S , 96°W-146°W. Sampling gear was longline fishing. With the precaudal length increment, the total gonad weight of male blue shark increases greatly but that of female increases little. The average value of TGSI(total gonadosomatic index) of female amounts to 0.64 but male increases to 0.98. The blue shark is viviparous and the period of parturition appears in Oct.-Nov. The sex ratio of adult blue shark is not fitted to 1:1. Preliminary results show that female matures at total length 183 cm(precaudal length 137cm). The broods range from 13 to 62 and average 34.29±11.2 (n=28). There is no obvious relationship between broods and maternal length. The length at birth arrives at total length 44cm. Based on the observation of egg diameter in the ovary of female blue shark, the maximum of egg diameter is 16-18 mm occurred in Nov. and at the same time fertilized eggs appear. Based on the clasper length analysis, the smallest male matures at total length 174 cm (precaudal length 131 cm).展开更多
In this paper, by using ocean surface temperature data(COADS), the study is made of the characteristics of the monthly and annual changes of the SST in the tropical western Pacific and Indian Oceans, which have impo...In this paper, by using ocean surface temperature data(COADS), the study is made of the characteristics of the monthly and annual changes of the SST in the tropical western Pacific and Indian Oceans, which have important influences on the climate change of the whole globe and the relation between ENSO(El Nio Southern Oscillation) and the Antarctic ice area is also discussed. The result indicates that in the tropical western Pacific and the Indian Oceans the change of Sea Surface Temperture(SST) is conspicuous both monthly and annaully, and shows different change tendency between them. This result may be due to different relation in the vibration period of SST between the two Oceans. The better corresponding relationship is obvious in the annual change of SST in the tropical Indian Ocean with the occurrence El Nio and La Nia. The change of the SST in the tropical western Pacific and the tropical Indian Oceans has a close relation to the Antarctic ice area, especially to the ice areas in the eastern south Pole and Ross Sea, and its notable correlative relationship appears in 16 months when the SST of the tropical western Pacific and the Indian Oceans lag back the Antarctic ice area.展开更多
文摘During July-November in 2003, pelagic fish survey was conducted by longliner covering areas of 03°S-17°S , 96°W-146°W. Sampling gear was longline fishing. With the precaudal length increment, the total gonad weight of male blue shark increases greatly but that of female increases little. The average value of TGSI(total gonadosomatic index) of female amounts to 0.64 but male increases to 0.98. The blue shark is viviparous and the period of parturition appears in Oct.-Nov. The sex ratio of adult blue shark is not fitted to 1:1. Preliminary results show that female matures at total length 183 cm(precaudal length 137cm). The broods range from 13 to 62 and average 34.29±11.2 (n=28). There is no obvious relationship between broods and maternal length. The length at birth arrives at total length 44cm. Based on the observation of egg diameter in the ovary of female blue shark, the maximum of egg diameter is 16-18 mm occurred in Nov. and at the same time fertilized eggs appear. Based on the clasper length analysis, the smallest male matures at total length 174 cm (precaudal length 131 cm).
文摘In this paper, by using ocean surface temperature data(COADS), the study is made of the characteristics of the monthly and annual changes of the SST in the tropical western Pacific and Indian Oceans, which have important influences on the climate change of the whole globe and the relation between ENSO(El Nio Southern Oscillation) and the Antarctic ice area is also discussed. The result indicates that in the tropical western Pacific and the Indian Oceans the change of Sea Surface Temperture(SST) is conspicuous both monthly and annaully, and shows different change tendency between them. This result may be due to different relation in the vibration period of SST between the two Oceans. The better corresponding relationship is obvious in the annual change of SST in the tropical Indian Ocean with the occurrence El Nio and La Nia. The change of the SST in the tropical western Pacific and the tropical Indian Oceans has a close relation to the Antarctic ice area, especially to the ice areas in the eastern south Pole and Ross Sea, and its notable correlative relationship appears in 16 months when the SST of the tropical western Pacific and the Indian Oceans lag back the Antarctic ice area.
