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Plecoglossus altivelis altivelis  (Temminck & Schlegel, 1846)

Ayu sweetfish
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Native range | All suitable habitat | Year 2100
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Plecoglossus altivelis altivelis   AquaMaps   Data sources: GBIF OBIS
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Image of Plecoglossus altivelis altivelis (Ayu sweetfish)
Plecoglossus altivelis altivelis
Picture by Islam, Md. S.

Classification / Names Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa

Actinopterygii (ray-finned fishes) > Osmeriformes (Smelts) > Plecoglossidae (Ayu fish)
Etymology: Plecoglossus: Greek, pleko, plekein = to fold + Greek, glossa = tongue (Ref. 45335).

Issue
All subspecies of Plecoglossus altivelis (Temminck & Schlegel, 1846) are synonymised under the species in Eschmeyer (CofF ver. Jul. 2010: Ref. 84883). Please send references, or more studies are needed.

Environment / Climate / Range Ecology

Marine; freshwater; brackish; demersal; amphidromous (Ref. 51243); depth range 10 - ? m.   Subtropical; 44°N - 23°N

Length at first maturity / Size / Weight / Age

Maturity: Lm 20.0, range 30 - 40 cm
Max length : 70.0 cm TL male/unsexed; (Ref. 12218); common length : 15.0 cm SL male/unsexed; (Ref. 35840); max. reported age: 3 years (Ref. 12218)

Short description Morphology | Morphometrics

Dorsal spines (total): 0; Dorsal soft rays (total): 10-11; Anal soft rays: 14 - 15; Vertebrae: 60 - 63. Pyloric caeca 350-400.

Distribution Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri

Northwest Pacific: western Hokkaido in Japan southward to the Korean Peninsula, Taiwan and China. A subspecies Plecoglossus altivelis ryukyuensis occurs in Nansei-shoto, Japan (Ref. 34989).

Biology     Glossary (e.g. epibenthic)

Typical amphidromous fish; appears in near shore from late autumn to spring (Ref. 11230). Found in lakes and rivers, preferring clean river water and can be found the entire river long, from the head to the mouth (Ref. 12218). Ascends the river during March when the temperature is around 10°C (Ref. 12218). Adults spawn in the spring, in the lower reaches of rivers. After spawning, some adults die while others return to the sea. Larvae enter the sea immediately after hatching and remain there during winter, feeding on plankton. In springtime, the young (5-7 cm TL) move upstream to the middle reaches of rivers to feed on algae. Fish (about 6-9 cm) start schooling at the river mouth and are insectivores and eat algae off small pebbles (Ref. 12218); this is assisted by small leaf-like teeth which are loosely attached to the jaw with two ligaments (Ref. 45181). Those that are ready to spawn (about 20 cm TL) move downstream to the lower reaches of the river. Spawning adults from the sea migrate upstream to the lower reaches as well. Some fish spawn two or three years in succession, others only once (Ref. 9987 & 559). River forms live usually only one year whereas lake forms can live two or three years (Ref. 12218). Reaches maturity at 30-40 cm (Ref. 12218). Highly esteemed food fish. Marketed fresh and consumed fresh, fried and broiled (Ref. 9987).

Life cycle and mating behavior Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae

During spawning some fish go up the river and some fish spawn on the river shoreline above pebbles. Spawns at night and excavates a 10cm (diameter or depth?) pit. Eggs are around 1 mm in size and adhere to the sand or pebbles for 14 to 20 days before hatching. This fish is semelparous and releases eggs many times over a short period each time releasing ~10,000 eggs. Sometimes females that want to spawn but cannot, save their strength, and go to a deep stagnant pool. These females wait until spring before going up the river with young fish. After hatching, the larvae are 6 mm and flow with the water current eating plankton. Juvenile fish will come again to the river in spring. These live in schools. When schools of Plecoglossus altivelis return to their river they guard their territory and eat food (Ref. 12218). Reproductive mode varies between semelparity and iteroparity. Large females spawn once, while smaller females spawn twice during a two-week interval (Ref. 76896).

Main reference Upload your references | References | Coordinator | Collaborators

Masuda, H., K. Amaoka, C. Araga, T. Uyeno and T. Yoshino, 1984. The fishes of the Japanese Archipelago. Vol. 1. Tokai University Press, Tokyo, Japan. 437 p. (text). (Ref. 559)

IUCN Red List Status (Ref. 96402)

CITES (Ref. 94142)

Not Evaluated

Threat to humans

  Harmless




Human uses

Fisheries: highly commercial; aquaculture: commercial; gamefish: yes
FAO(Aquaculture: production; fisheries: production, species profile; publication : search) | FisheriesWiki | Sea Around Us

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Internet sources

Alien/Invasive Species database | BHL | Cloffa | BOLDSystems | Websites from users | Check FishWatcher | CISTI | Catalog of Fishes (gen., sp.) | DiscoverLife | Faunafri | Fishtrace | GenBank(genome, nucleotide) | GOBASE | Google Books | Google Scholar | Google | IGFA World Record | iSpecies | National databases | PubMed | Scirus | SeaLifeBase | Tree of Life | uBio | Wikipedia(Go, Search) | World Records Freshwater Fishing | Zoological Record

Estimates of some properties based on models

Phylogenetic diversity index (Ref. 82805):  PD50 = 1.5000   [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), based on all LWR estimates for this body shape (Ref. 93245).
Trophic Level (Ref. 69278):  2.8   ±0.16 se; Based on food items.
Resilience (Ref. 69278):  High, minimum population doubling time less than 15 months (tm=1; tmax=3; Fec=50,000-100,000).
Vulnerability (Ref. 59153):  Low to moderate vulnerability (30 of 100) .
unknown
Price category (Ref. 80766):   Unknown.