Capture (blue) and aquaculture (green) production of Japanese hard clam (Meretrix lusoria) in thousand tonnes from 1950 to 2022, as reported by theFAO[1]
Meretrix lusoria, thehamaguri,Asian hard clam orcommon Orient clam, is a species of saltwater clam, a marinebivalvemollusk in the familyVeneridae, the Venus clams. This species is native to Asia, originally described around the waters ofJapan.[2] It is commercially exploited forsushi, and its shells are traditionally used to make whitego stones.
The hamaguri clam is the subject of a haiku byMatsuo Bashō.[3]
Distribution of morphologically similarMeretrix species per Hsiao & Chuang (2023)[2]
Meretrix lusoria is morphologically similar to a number of closely related species,[2] making identification and reports of distribution quite confusing. Less precise sources may describe a large range in East Asia, in waters tropic to temperate.[4] However, as Hsiao & Chuang (2023) demonstrated using molecular (nuclear + mtDNA) and multi-variate morphological means, it is possible to distinguish several species:
Meretrix lusoria, originally described around Japan, is distributed in the waters of Japan and South Korea.[2]
Meretrix taiwanica, misidentified as others on the list until 2023, is found around Taiwan and southern China.[2][5]
Meretrix meretrix, originally described by Linnaeus in the Indian Ocean, is found around Indian Ocean and Southeast Asia.[2]
There is one report in 2022 ofM. lusoria appearing inSarawak (MalaysianBorneo). The identification was confirmed by mtDNA phylogeny matching to JapaneseM. lusoria. Interestingly, what appeared morphologically to beM. meretrix andM. lyrata at the same site gave very similar mtDNA results.[6]
.jpg)
_(15194854407).jpg)
.jpg)