1Hokkaido Aquaculture Promotion Corporation, Sapporo, Hokkaido 060-0003, 2Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido 060-0809, 3Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Hokkaido 060-0809, Japan
The upriver spawning migration of shishamo smelt Spirinchus lanceolatus tagged with nano-tag radio transmitters was investigated for both the effects of surgically implanted radio transmitters on swimming and spawning behavior in an experimental water tank and during the upriver spawning migration in the Mukawa River, Hokkaido, Japan. There was no significant effect on the cruising and burst speed, spawning behavior or the physiological status between the tagged and control fish in the experimental water tank. Average swimming speed of the tagged fish during the upriver migration ranged from 3.8 to 17.8 cm/sec. The tagged fish tended to migrate around the center of the stream and predominantly used an area where the water velocity was less than 60 cm/sec with woody debris as a holding habitat. The present study reports on the upriver migration of small-sized shishamo smelt for the first time.