Spawning Ground of the Salmonoid Fish, Salangichthys microdon, in Takahashi River, Okayama Prefecture
Spawning Ground of the Salmonoid Fish, Salangichthys microdon, in Takahashi River, Okayama Prefecture
复制标题
冈山县高桥川鲑鱼产卵场
DOI：
10.11369/jji1950.20.25
复制
发表时间：
1973
期刊：
影响因子：
--
通讯作者：
T. Senta
中科院分区：
文献类型：
--
作者：
T. Senta
Sand samples from the bottom of the fishing ground of Salangichthys microdon in the Takahashi estuary were collected from 33 stations for the examination of naturally spawned eggs of the fish. The eggs were found among sand grains collected from 7 stations. Eggs were most abundant, 870 eggs per300ml sand grains, at the sand bar exposed only at the low tide and is located near the estuary dam, 5.2 km upstream from the river mouth. The next highest density, 238 eggs per 300ml sand grains, was observed at the station near the river mouth. Eggs at various developmental stages were observed. The eggs, even those in the sand bar, were found to be developing successfully in spite of the wide range of fluctuation of chlorinity (0.8%, at low tides to 16.8%, at high tides). The spawning ground is mainly composed of sand grains ranging from one-third to equal diameter of eggs (0.92-0.95 mm). No eggs were found to be attached to the thalli of the sea-weed, Enteromorpha prolifera, which flourished on the concrete floor of the dam and on the rubble mound below it. However, in lakes such as Kasumigaura, it has long been believed that the fish lay their eggs on the stems and leaves of aquatic plants. This difference in the spawning habits may be attributed to the difference of water currents. Since there are relatively few records of the collection of naturally spawned eggs in lakes, further investigation is essential to confirm whether the fish in lakes do not lay their eggs into sand.(Research Department, Southeast Asian Fisheries Development Center, Changi Point, Singapore)シラウオ Salmgichthys microdon Bleeker の 産卵床に関する従来の知見は, 例 えば松原・落合 (1965) に示されているように," 卵 は粘着性があり, 水 草の幹や葉に粘着する" と 要約される. 筆者は岡山県高梁川のシラウオ漁場における河口底質の採集を通 じて, 卵 は水草にではな く砂粒に粘着 していることを観察した. 同 漁場の性状, 漁 獲高, シ ラウオに関する生物学的知見な どは別途に報告した (千田 B, 1973).