Relationship between Body Size of Ayu Migrating up Rivers Flowing into Toyama Bay and Water Temperature
Relationship between Body Size of Ayu Migrating up Rivers Flowing into Toyama Bay and Water Temperature
复制标题
流入富山湾的河流上迁徙的香鱼体型大小与水温的关系
DOI：
10.11233/aquaculturesci1953.52.315
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Y. Tago
中科院分区：
文献类型：
--
作者：
Y. Tago
1994 ~ 2003年，在流入富山湾的寿江和津津津江下游及津津河口附近海域，调查了香鱼溯河标准体长与水温的关系。随着水温的升高，香鱼最小体长逐渐减小，最小标准体长（y）与水温（x）的关系符合线性回归曲线y = 8.48 ± 0.174x（P<0.001）。在海水中采集的香鱼最大体长随海水温度的升高而减小，最大体长（y）与海水温度（x）的关系符合线性回归曲线y =11.2 ± 0.291x（P = 0.004）。当水温达到10 ℃时，香鱼开始向河流中迁移，当水温超过17 ℃时，香鱼就不再被采集到海里。最早溯河迁徙的香鱼平均体长最大的原因被认为是个体较大，对冷水的耐受性较强。3月下旬至6月中旬，香鱼向寿河迁移的时间为27 ~ 69天。对于海流型香鱼幼鱼的放流，认为在水温10 ℃时的放流初期，宜放流较大的个体（标准体长·<$9 cm），在水温接近14 ℃时的放流高峰期，可放流较小的个体（标准体长·<$6 cm）。
Relationship between the standard length of ayu Plecoglossus altivelis migrating up rivers and the water temperature of the rivers was investigated from 1994 to 2003 in the lower reaches of the Shou and Jinzu rivers flowing into Toyama Bay and the sea near the mouth of the Jinzu River . The minimum length of ayu collected in both rivers gradually decreased as the water temperature of the river increased, and the relation between the minimum standard length (y) of ayu and water temperature (x) fitted a linear regression curve as expressed by y = 8 .48 0.174x (P<0.001). The maximum length of ayu collected in the sea was found to be smaller as the water temperature of the sea increased, and the relation between the maximum length (y) of ayu and water temperature (x) fitted a linear regression curve as expressed by y =11.2 0.291x (P = 0.004). The migration of ayu into the rivers started when the water temperature reached 10•Ž, and ayu were not collected in the sea when the water temperature exceeded 17•Ž. The reason why the mean body size of the ayu migrating up rivers earliest is largest is considered to be that larger individuals can better tolerate cold water. The period of ayu's migration into the Shou River was estimated for 27 days to 69 days during late March to middle June. In the case of stocking of ayu juveniles derived from sea-run type into a river, it is considered that bigger individuals (standard length •† 9 cm) should be released in the first period when the water temperature is at 10•Ž, and smaller individuals (standard length •† 6 cm) could be released in the peak period when the water temperature approaches 14•Ž .