ANALYSIS OF SWIMMING ABILITY OF POND SMELT(Hypomesus nipponensis) AT THE SPAWNING STAGE FOR FISHWAY DESIGN

Abstract

 To understand the swimming ability of small diadromous fish, swimming experiments were conducted using Pond smelt (Hypomesus nipponensis) at the spawning stage . Our results are as follows: 1) average swimming speed of Pond smelt with body lengths ranging from 6 to 8 cm was found to be 107-141 cm/s, 2) a swimming-curve formula defining the relationship between swimming speed and swimming time was obtained, and 3) a swimming distance curve formula defining the relationship between swimming distance and flow velocity was obtained. It was estimated that a Pond smelt can advance itself 120 cm at a flow velocity of 87 cm/s using swimming distance curve. This formula is expected to be a new index for a distance in high-flow velocity range in a fishway design.