Preferential behavior of <i>Tribolodon hakonensis</i> for fishways according to biological characteristics

In 2012, the fishway in Miyanaka Intake Dam Niigata Prefecture, Japan, was reconstructed and divided into three fishways (ice-harbor-, stair-, rock-ramp-type) with different flow velocities water depths. We conducted an adaptive monitoring survey these from 2012 to 2020, 33 fish types were found, including migratory, swimming, small benthic fishes. Many species displayed a preference for specific fishways. The run-up Tribolodon hakonensis studied determine effects of physical parameters such as body length, rush speed instantaneous temperature, presence/absence nuptial coloration on preference. T. had greater length higher speeds than those without it. They also preferred ice-harbor fishway, whereas their shorter, uncolored counterparts stair rock-ramp alternatives. environmental conditions selected by changed according growth stage, did Changes may have influenced observed differences populations. It thus confirmed that developing depths is effective supporting various life stages hakonensis.