Influence of water velocity on spawning behavior and egg survival of shishamo smelt
2006
Nii, H.(Hokkaido Univ., Hakodate (Japan)) | Ueda, H.
Our previous work has shown the density of spawned eggs of shishamo smelt, Spirinchus lanceolatus, to be influenced by the water velocity of the river. The purpose of the present study is to investigate the influence of water velocity on spawning behavior and egg survival of shishamo smelt in a water tank. Three different experiments were carried out on the influence of water velocity on the mating behavior, the influence of water velocity on the exfoliation of eggs, and the influence of a mud covering on the survival of eggs. When the water velocity exceeded 0.6 m/sec, the adult smelt were not able to display spawning behavior, and any eggs became easy to exfoliate. Egg survival rate decreased with covering depth of mud over 4 mm. These data may be useful for the conservation and restoration of spawning habitats of shishamo smelt in their native rivers.
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