Abstract
This paper describes the cruising speed of fresh water fishes. Most of the previous studies about measurement the cruising speed have not consider spatial and temporal distributions of velocity of water flow. We made experiments on cruising speed in open channel which has gravel water bed.
The experiment result indicated that the cruising speed was a few times as fast as the cruising speed measured in the past. This difference is though to be due to non-uniform distribution of flow velocity. This result indicates that small spaces with low velocity area are important for aquatic organism. This study shows that the spatial distribution of flow velocity is more important than the mean velocity to understand behavior of aquatic life.
