Fish · GBIF taxon 4283980
Sweetfish
Plecoglossus altivelisAlso known as Ayu, Ayu Sweetfish, Sweetfish Smelt
Ayu sweetfish are celebrated in East Asian rivers for their sleek, silvery bodies and distinct melon-like aroma. Young fry migrate down to coastal waters for the winter before returning upstream in spring to scrape microalgae off submerged rocks using specialized comb-like teeth. Adults aggressively defend rich algal feeding territories before completing their brief, one-year life cycle during autumn spawning runs.
AmphidromousRiverineEast Asian
—observations
—countries
—peak records
Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Diet & prey
- Benthic Algae
- Diatoms
- Aquatic Insects
Predators
- Great Cormorant
- Grey Heron
- Predatory River Fish
ThreatsDam construction, river alteration, and habitat pollution
HabitatsClear rivers, gravelly stream beds, and coastal estuaries
Life span1 year
Size / weightNot available
Classification
- FamilyPlecoglossidae
- SpeciesPlecoglossus altivelis
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Safe to observe at a normal distance.
Responsible observation
- Spotting Scrape Marks: Look for clean, oval patches on sunlit river rocks where adults graze on algae.
- River Etiquette: Keep a respectful distance from active spawning beds in shallow gravel riffles during autumn.
Frequent Companion opencage / CC BY-SA 2.5 · CC BY-SA 2.5
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