Larval ayu Plecoglossus altivelis occurring in the Shimanto estuary.
Larval ayu Plecoglossus altivelis occurring in the Shimanto estuary.
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香鱼幼体 Plecoglossus altivelis 出现在四万十河口。
DOI：
10.2331/suisan.56.871
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发表时间：
1990
影响因子：
0.4
通讯作者：
Masaru Tanaka
中科院分区：
文献类型：
--
作者：
I. Takahashi;I. Kinoshita;K. Azuma;S. Fujita;Masaru Tanaka
在双栖型的香鱼Plecoglossus altivelis Temminck et Schlegel中，秋季在河流中孵化的前幼虫通常会漂流到海里，在那里他们生活在整个幼虫和早期幼鱼阶段，直到春天。然而，在四万十河口，数量可观的postlarval香鱼不仅发生在3月至5月，但也在10月至2月。此外，在河口和海水中出现的幼虫的大小和年龄的差异不大。在河口，它们生活在岸边沃茨，年龄为10 - 75日龄，水深为10 - 30 mm。从那以后，他们似乎不出海就溯河而上。从耳石日轮估计的增长率是在河口比在海上海滩。
In the amphidromous form of ayu Plecoglossus altivelis Temminck et Schlegel, generally the prelarvae hatched in rivers in autumn are drifted down into the sea, where they live throughout the larval and early juvenile stages until spring. In the Shimanto estuary, however, an appreciable number of postlarval ayu occurred not only during March to May, but also during October to February. Furthermore, there was little difference in the size and age between the larvae occurring in the estuary and sea. In the estuary, they reside in the bank waters, during 10-75 day ages and 10-30mm SL. Thereafter, they seem to ascend the river without going out to the sea. The growth rate estimated from the otolith daily rings was higher in the estuary than in the sea beach.