Predation on released masu salmon fry Oncorhynchus masou masou by fluvial sculpin Cottus nozawae

Key Points

• This research aims to examine the impact of predation by fluvial sculpin on masu salmon fry immediately after their release.
• Analyzed stomach contents of fluvial sculpin after the release of masu salmon fry.
• Monitored predation rates over a two-week period post-release.
• Compared predation rates after one month to assess changes in feeding behavior.
• Over 60% of fluvial sculpin were found to have consumed masu salmon fry within two weeks post-release.
• After one month, very few fluvial sculpin were recorded preying on masu salmon fry.
• When predation occurred after one month, only a single fry was typically identified in the stomach contents.