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Ayu (Plecoglossus altivelis) — Plecoglossidae

Ayu

Plecoglossus altivelis
LC · Least Concern

The Ayu (Plecoglossus altivelis) is a fish that lives in both fresh and salt water of the family Plecoglossidae that grows up to 70 cm.

Length
70 cm
Water
Euryhaline
Depth
10.0–? m
Diet
Omnivore
Behaviour
Schooling
Activity
Diurnal
Body shape
Elongated (eel-like)
Substrate
Stone or rock
Danger
Harmless
Edibility
Highly prized

Description

The ayu is a slender, smelt-like migratory fish of the family Plecoglossidae reaching about 70 cm but usually much smaller. The silvery-green body has an adipose fin, as in salmonids, and comb-like teeth with which the fish scrapes diatoms and algae off stones. Adults fiercely defend a grazing territory. The species comes from East Asia and is amphidromous and largely annual: larvae wash to sea, young fish run up the clear river, and after spawning in autumn most die. The flesh smells characteristically of watermelon or cucumber. In Japan the ayu is a highly prized seasonal fish, traditionally caught with the tomozuri method.

Frequently asked questions

How do you recognise the Ayu?

The Ayu has an elongate, eel-like body, is mainly silver-grey and shows a plain pattern.

Where does the Ayu live?

The Ayu lives in both fresh and salt water and is mostly found around stony or rocky ground.

How big does the Ayu get?

The Ayu grows to a maximum of about 70 cm. On average the species is around 15 cm.

Is the Ayu dangerous to humans?

No, the Ayu is harmless to humans.

Is the Ayu edible?

Yes, the Ayu is a highly prized food fish.

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All data

Identification

Dutch name
Ayu inferred
English name
Ayu verified
Scientific name
Plecoglossus altivelis
Family
Plecoglossidae
Other names
Ayu; Ayu sweetfish; Ko-ayu; Ryukyu ayu-fish verified

Appearance

Size class
Large verified
Max length (cm)
70.0 verified
Average length (cm)
15.0 verified
Body shape
Elongated (eel-like) sourced
Dominant colour
Silver / grey sourced
Pattern
Plain sourced
Tail shape
Forked inferred
Mouth position
Terminal inferred
Lips
Thick / fleshy inferred
Barbels
No verified
Dorsal fins
One continuous sourced
Dorsal spines
No verified

Habitat & distribution

Water type
Euryhaline verified
Substrate
Stone or rock verified
Min depth (m)
10.0 verified
Origin
Native verified

Behaviour & biology

Diet
Omnivore verified
Social behaviour
Schooling verified
Territorial
Yes verified
Activity
Diurnal inferred
Reproduction
Separate sexes verified
Sexual dimorphism
Yes verified
levensduur_max_jaar
3.0 verified

For anglers

Edibility
Highly prized verified
Fishing method
In Japan traditioneel met de levende lokvis-methode (tomozuri), die het territoriumgedrag uitbuit; een zeer gewaardeerde seizoensvis sourced
Regulations source
FishBase ↗ inferred

Safety

Danger to humans
Harmless verified

Status & sources

Sources
FishBase via GBIF (DwC-A), CC-BY-NC 4.0

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