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Kim Eul-Bae
- Korean Journal of Fisheries and Aquatic Sciences
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- v.3 no.4
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- pp.228-232
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- 1970
From the standpoint of fishery science it is an interesting matter to note that the size of Plecoglessus altivelis population on Cheju Island is smaller than that of the Nakdong River located in the southern part of Korea's mainland. Therefore the author carried out a comparative analysis to determine whether the populations differ because of racial or because of environmental conditions. The morphometric characters of the head length and the body length were used for the analysis of covariance and computed by a standard regression method of testing for the homogeneity of the populations. All samples were collected during 1968 and 1969 in the Milyang Stream of the Nakdong River and the Cheonji Stream of Cheju Island. The results of the analysis of the populations based on the significance test are as follows: 1. Since the F value observed was only 1.023 ($n_1=1,\;n_2=42$) the conclusion was reached that the samples could both belong to the same population. 2. In comparison with the deviations of the regression coefficients between the fish of the Nakdong River and Cherinji Stream, the populations were also highly significant suggesting that thelr belong to the same population. 3. The conclusion is that the fish of Cheju Island became a smaller fish in size due to an environmental condition but not due to racial characteristics.
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Ko, Myeong-Hun;Kim, Ik-Soo;Park, Jong-Yeong;Lee, Yong-Joo
- Korean Journal of Ichthyology
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- v.19 no.2
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- pp.142-153
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- 2007
Fertilized eggs of Plecoglossus altivelis over than 1,000,000 were introduced into Okjeong, Jeollabuk-do, Korea by K-water, 2001. Since then, this lake and the neighbouring tributaries gave sufficient habitat to maintain their life cycle which are being the land-locked. A land-locked ayu of annual life is ascending and descending from Lake Okjeong to streams for spawning and growth. Among the streams, the Churyeong stream reaching about 32 km in length is a major site for growth and spawning. But the land-locked ayu was no longer seen in the upper regions of the Churyeong stream over than about 12 km distance from Lake Okjeong. Because there were 11 weirs along with the Churyeong stream, it was difficult for them to move freely up to upper regions, and it causes irregular growth condition although they must be actively growing with feeding for spawning. During three survey years (2004 to 2006), in lowest rainfall-recorded 2005, the ayu population was not able to move up actively across the weirs and just stayed around the weirs, and finally it let them grow slowly and unstably. Also although there are 11 weirs, only 3 fish ways existed. Such environmental factors will seriously affect growth, spawning and size of ayu population in this area.
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MOON Soo-Kyung
- Korean Journal of Fisheries and Aquatic Sciences
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- v.26 no.3
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- pp.241-249
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- 1993
The class and fatty acid composition of neutral lipid(NL) and phospholipid(PL) of Korean sweetfish were experimented. The NL was mainly consisted of triglyceride ($94.8{\sim}99.5\%$), and also identified free sterol($0.29{\sim}2.77\%$), sterol ester and diglyceride in less quantity. Triglyceride content of viscera was much higher than those of other tissues. Main components in the PL were phosphatidylcholine(PC, $7.9{\sim}61.6\%$), phosphatidyl ethanolamine(PE, $19.3\%{\sim}39.3\%$) and followed by diphosphatidyl glycerol and sphingomyelin. PC and PE contents were higher in muscle and head tissues. The major fatty acids in NL fractions of sweetfish were 16:0, 18:1n-9, 16:1n-7, 18:2n-6, 18:0 and 14:0. Fatty acid composition of NL was similar to those of total lipid and were not significantly different among the fishes, the large and small sweetfish. In case of PL fractions, the major fatty acids were 16:0, 18:1n-9, 22:6n-3, 18:0 and 18:2n-6.
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