Asian moon scallop (Amusium pleuronectes)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Mollusca · Class: Bivalvia · Order: Pectinida · Family: Pectinidae · Genus: Amusium.

Accepted name: Amusium pleuronectes · Authority: (Linnaeus, 1758) · Taxonomic status: accepted · AphiaID: 215388.

Synonyms and superseded combinations recorded for this taxon: Amusium magneticum Röding, 1798; Amusium pleuronectes australiae T. Habe, 1964; Amusium pleuronectes nanshaensis Z.-R. Wang & R. Chen, 1991; Ostrea pleuronectes Linnaeus, 1758; Pecten (Amusium) milneedwardsi De Gregorio, 1884; Pleuronectia laevigata Swainson, 1840.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=215388 (CC BY 4.0). Accessed 2026-09-25.

Biology and life history (SeaLifeBase)

Measured values published by SeaLifeBase for Amusium pleuronectes. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 10 cm · Common length: 8 cm · Depth range: 10–160 m · Habitat zone: benthic · Vulnerability index: 10 of 100 · Fishery importance: commercial · Aquarium trade: never/rarely.

SeaLifeBase notes: Maximum depth from Ref. 101147. It is part of trawl bycatch (Ref. 128042).

Widely distributed in Indo-Pacific coasts (Ref. 122164). Occurs in large schools in shallow waters with sand and muddy bottoms (Ref. 80041). Also found on clean sand with silt and shell rubble, where the lower right valve is buried in soft sediment (Ref. 101147) as well as on river mouth and estuary (Ref. 122165).

Source: SeaLifeBase species summary (SpecCode 84376) — https://www.sealifebase.se/summary/Amusium-pleuronectes.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.

Distribution and occurrence records (GBIF)

2,968 georeferenced occurrence records for Amusium pleuronectes are published through GBIF from 17 countries or marine areas. The map above plots 317 distinct locations from a sample of 2,968 records, omitting 76 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: Australia (2,609); China (111); Philippines (101); Indonesia (34); Viet Nam (23).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 4374006) — https://www.gbif.org/occurrence/search?taxon_key=4374006&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=215388 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-25.

Description and natural history (Wikipedia)

One subspecies is recognized, being Amusium pleuronectes okinawaensis Masuda, Sato & Shuto, 1986.

Relation to humans

This scallop is consumed throughout its range, with efforts being made to establish aquaculture of the species.

Description

Unlike those of the genus Pecten, the two near-circular valves of A. pleuronectes are nearly symmetrical, with the lower or right valve being slightly deeper than the upper or left valve. The two very smooth valves are also differently colored (though both have apparent radial lines and growth marks), with the left valve being some shade of pinkish-brown and the right valve white. Individuals are often 8 cm long (defined as shell height), and a maximum shell height of 10 cm is reported.

There are 22 to 34 internal radial ribs on the shell; the supposed southern subspecies A. pleuronectes australiae apparently has 22-24 ribs, fewer than the nominate subspecies.

Biology

A. pleuronectes ranges in depth from 10 - 160 m, and often aggregates in large "schools". This species is benthic, but is one of a few species of scallop which are considered gliders, which swim more efficiently than most other species (defined as swimming more than 5 m/effort); the flattened valves allow the scallops to glide during a level swimming phase. Other species with this niche include members of Adamussium, Placopecten, and Ylistrum. The convergent evolution of these species is so extensive that the species of Ylistrum were historically considered part of Amusium, and were only recognized as distinct through analysis of DNA and close examination of internal ribbing patterns.

Being filter feeders, these scallops consume diatoms such as Isochrysis galbana, Tetraselmis tetrahele, and Chaetoceros sp..

A. pleuronectes is protandrous, and reproduces throughout the year with a major peak in February and a minor peak between July and September. First maturity occurs around 5.4 cm in shell height.

A. pleuronectes is targeted by fisheries; peak season in the northern Philippines is April-June. They are edible and sold at wet markets throughout its range, such as Malaysia, and Indonesia. In Hong Kong, the meat is dried and sold for cooking double-stewed soup.

Aquaculture has been attempted for this species; natural spawning in controlled conditions were more effective than attempting to induce spawning behavior.

Source: Wikipedia: Amusium pleuronectes — https://en.wikipedia.org/wiki/Amusium_pleuronectes (CC BY-SA 4.0). Accessed 2026-09-25.