Studies on the juvenile Japanese sea bass in the Chikugo estuary of Ariake Bay. Changes in distribution pattern and condition coefficient of the juvenile Japanese sea bass with the Chikugo River ascending.
Studies on the juvenile Japanese sea bass in the Chikugo estuary of Ariake Bay. Changes in distribution pattern and condition coefficient of the juvenile Japanese sea bass with the Chikugo River ascending.
复制标题
有明湾筑后河口的鲈鱼幼鱼的研究。
DOI：
10.2331/suisan.48.129
复制
发表时间：
1982
影响因子：
0.4
通讯作者：
Masaru Tanaka
中科院分区：
文献类型：
--
作者：
Y. Matsumiya;T. Mitani;Masaru Tanaka
从1979年开始，对有明湾筑后河口的鲈鱼幼鱼进行了研究。本文主要利用1980年的资料，研究了分布格局和条件系数随上升进程的变化。在3月中旬、3月下旬和4月中旬进行了总共7天的研究。采用直径1.3m的幼网进行拖航，在河口至流域共设7个站位进行环境观测。1)共采集仔稚鱼5314尾，拖网183条。随着研究的进行，分布模式由高盐度向低盐度转移。2)标准长度平均值分别为14.6、16.1和20.1mm。体高比随体长的增长而增大，在标准体长20mm后，体高比趋于稳定。20mm后，条件系数继续增加，并有一段平缓的曲线。3)我们不能只根据研究区域的盐度来检查海鲈鱼的实际分布。1979年，距离概念被引入渔获量和盐度的时间变化。1979年，在各站进行了连续采样。4)3月中旬，鲈鱼主要分布在海、淡水沃茨分界带的靠海一侧。在4月中旬，其中一半已经到达淡水区。淡水区个体的条件系数显著增加。研究了溯河过程中体长和状态系数的变化。5)在涨潮或退潮时，当潮汐转向时，渔获物发生显著变化，涨潮时的渔获物比退潮时多。可以说，海鲈鱼的分布模式取决于潮汐高度和潮汐时间。并对海鲈鱼的上升机制作了初步探讨。
The research on the juvenile Japanese sea bass in the Chikugo River estuary of Ariake Bay is proceeded from 1979. In this paper, we examined the changes in the distribution pattern and the condition coefficient with the ascending progress, mainly using the data obtained in 1980. The researches of seven days in total were executed in mid March, late March and mid April. Surface towing by a larva net with 1.3m in a diameter and environmental observations were performed at seven stations set from the estuary to the river basin. 1) A total of 5314 postlarvae and juveniles were collected by 183 tows. As the researches proceeded, the mode of the distribution moved from higher to lower salinity. 2) The mean of standard length during each research was 14.6, 16.1 and 20.1mm, respectively. The ratio of body depth increases in proportion to the length growth and after 20mm in standard length, the ratio keeps stable. Condition coefficient continues to increase with a gentle curve for a while after 20mm. 3) We could not examine an actual distribution of sea basses only in reference to the salinity in the research area. The concept of distance was introduced to the temporal changes in catch and salinity in 1979. In the year 1979, the continual samplings at each station were performed. 4) In mid March, sea basses were mainly distributed in the sea side of the boundary zone between sea and fresh river waters. In mid April, half the number had already reached the fresh water area. Individuals in the fresh water area had considerably increased the condition coefficient. Changes in body length and condition coefficient under ascending a river were examined. 5) Remarkable change in catch when the tide is turning at high or low tide and more catch during rising than during ebbing tide were observed. It may be said that the sea basses display alternative distribution patterns dependent on tidal levels and tidal hours. Preliminary notes on the ascending mechanism of the sea basses were given.