Trough Shell & Its Adductor Muscle

I don’t know why, but trough shell has another name: “stupid clam”, and every time I think about this shellfish, that is the first thing which comes into my head. So I have begun writing about the trough shell with this anecdote. Sorry, though shells! I learned that name is because Trough shells were caught in ridiculously huge numbers in the Tokyo and Chiba area.

However, trough shells are called “aoyagi” in Japanese when they are served at sushi restaurants. “Aoyagi” is actually just a name of a place in Chiba Prefecture, where this shellfish used to be gathered and distributed. But it is also a name given particularly to the weeping willow with fresh & green leaves - in that context, “aoyagi” is a seasonal word for “spring” when composing “haiku” poems. When we Japanese people hear “aoyagi”, we imagine the weeping willow: a tree with slender, hanging branches with green leaves, which droop toward the ground near the edge of a narrow stream, the branch sometimes sway in the spring breeze.

Apart from merely talking about its name, let’s eat some trough shell sushi! It is shaped like a leaf. Its color is graduated; orange-yellow(the color of its tip of foot) to ivory(the color of its base of foot (and its body?) ). Tender, slightly crisp, sweet, having the aroma of the ocean - these are some of impressions you may have when you taste it. In my opinion, they are moderate and elegant in taste. Through shells might have been caught in excess, but the catches have been decreasing in recent years (except for those that are cultivated). Maybe it is time to refresh the past image of the shellfish, and appreciate them on the plate as the precious gift of sea with a beautiful name “aoyagi”.

The adductor muscles* of the trough shell make another topping named “ko-bashira*”, which is generally offered as “battleship roll” because the muscles are small pieces, and cannot stay on the sushi rice without the support of the dried seaweed around it. Here, I have a question. Besides the main body of the trough shell, it is only the adductor muscles which are eaten; I wonder what they do with the rest of it? We can sometimes see that packages filled with the adductor muscles being sold at fish market. Maybe the other parts are not so delicious, or not edible (please give me time to investigate the whereabouts of them…) Trough shell adductor muscles are sweet, and the strings of the muscles break apart in your mouth. It is totally different texture from that of scallops (they are adductor muscles as well), and I agree that the best way to enjoy them raw is to make a battleship roll, a small heap of the muscles on top.

*Adductor muscles are used to open and close the shells of the bivalves.

*Ko-bashira means “small pillar” in Japanese.