noun
mirugai clam; gaper clam (Tresus keenae)
A species of large saltwater clam found in Japan; often used in sushi and sashimi. The name is sometimes associated with the seaweed 海松 (miru).
See also: 海松食
ミルガイは寿司ネタとして人気がある。
Mirugai is popular as a sushi topping.
市場で大きなミルガイを買った。
I bought a large mirugai clam at the market.
The name likely combines 海松 (miru, a type of seaweed) and 貝 (kai, shellfish), possibly from a perceived resemblance. The exact origin is uncertain.