Rediated trough-shell（Aoyagi）is another name for bakagai shellfish and its legs are eaten. The bright orange colored flesh has a firm texture and its rich ocean flavor spread in the mouth. The name aoyagi came from its producing area, Aoyagi village (currently Ichihara city Chiba prefecture).
Trivia : Generally shellfish has trace amounts of taurine, but there are copious amounts in round clam. This is a type of amino acid and is thought to be good for high blood pressure.