| Studies were carried out on the distribution,abundance and growing condition of Euphausia superba in the Southern Ocean,and on the spatial distribution,diel vertical migration and egg production,hatchability and early larval development of Euphansia pacijica in the East China Sea and the Yellow Sea. The main results are as follows:1. The circumpolar distribution,abundance and growing condition of Euphansia snperbaThe author studied the Euphansia superba samples obtained during 1992 1993,1997 1998 and 1999 2000 Chinese Antarctic Expedition. The results show that the circumpolar distribution pattern of Euphausia superba was obvious,it was mainly distributed in two regions,the Weddell Sea Region (0 -80 W) and the Prydz Bay Region (45 -90 E),also we obtained some samples in the Ross Sea Region (145 -180 W). The abundance of Euphausia superba was usually higher in the Weddell Sea Region than that in the other two regions,and the stations with the most abundant Euphansia superba were usually found in this region. In the Ross Sea Region the occurrence of Euphansia superba was very low. There was interannual variation in the distribution of Euphausia superba,and it seems that the abundance decreased from 1992 1993 to 1999 2000 in the Weddell Sea Region. The growing condition of Euphausia superba was not the same according to the different seasons in the same region and to the different areas in the same seasons. The growing condition of Euphausia superba were complex in the Weddell Sea Region than that in the other two regions.2. The distribution,abundance and growing condition of Euphausia superba in thePrydz Bay RegionSamples of Euphausia superba were collected from the Prydz Bay region during the austral summer of 1999 2000. Results show that the density was comparatively low in the Prydz Bay Region than that in the Southern Atlantic Ocean. The distribution of Euphausia snperba in the Prydz Bay Region was very patchy,its abundance was higher in the slope area (the pelagic area between the isobaths 1000 m and 3000 m) than the open sea area (the pelagic area beyond the 3000 m isobath). The developmental stages of the Euphausiasuperba were mostly of the post-larval stages. The male adults mature earlier than the female adults. The krill were growing better in the slope area than in the open sea area,and as far as the whole study area was concerned,they were under normal growing condition. The relationships between the distribution and abundance of Euphausia superba and the distribution of the surface temperature,salinity and Chi a were not obvious. However it seems that the distribution and abundance of Euphausia superba was related to the cold water mass exist at 30 -100 m,and with the confluence area between the high and the low Chi a centers at 25 m depth.3. The spatial distribution of Euphausia pacifica in the East China Sea and the YellowSeaWe analyzed the materials of the general investigation in 1959 and the field investigation of the "973 program" in 2000-2001. The results of the general investigation in 1959 show that the Euphausia pacifica was mainly distributed in the east of 122 E in the investigation area. During January to March,they mainly distributed in the area east of 122 E in the Yellow Sea and south of 30 N in the East China Sea. During April to June,the main distribution area moved southward. During July to September,the main distribution area was retreated to the Southern Yellow Sea. In October,the distribution area extended to the near shore waters. During November to December,the north limit of the distribution area moved southward,and in December,the distribution area seems to be confined to the area south of 34 N. Euphausia pacifica can live in a wide temperature range in the East China Sea and the Yellow Sea,from 6C to 22-23 C,but its optimal temperature was restricted to 9-12C. The result of field survey of "973 Program" shows that the distribution pattern of Euphausia pacifica did not change greatly during the past few decades.4. The diel vertical distri...
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