“Ubagai/姥貝” (Pseudocardium sachalinense) or more commonly called “Hokkigai/北寄貝” when served as sashimi or sushi have many names in English.
Member of the Trough Shells Groups, they are called Surf Clams, or more precisely, as pertains to the varieties eaten in Japan, either Japanese Surf Clams or Sakhalin Surf Clams as they are collected both along Japan and Sakhalin Islands shores. in Ainu, the original language of Hokkaido, it is called “poksey” or tutturep”.

8,000 tonnes are caught in Japan every year. 94% of fresh/live Surf Clams are collected in Hokkaido, Aomori, Fukushima and Miyagi Prefectures.
About 4,000 tonnes are imported frozen from Canada.
They are popular dried, in soups or cooked with vegetables and rice.

Their “tongues” can be appreciated as sashimi, but are most popular lightly poached and cooled down.
The color is black when raw.

The tongue turns red when it is heated as bakes, steamed or boiled.

That is the way they are usually processed before being served as sushi nigiri, either straight, or with a few small incisions for better effect! Very satisfying and beautiful!

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The Indian Tourist, Masala Herb by Helene Dsouza in Goa, India
Mummy I Can Cook! by Shu Han in London
Pierre.Cuisine, Francescannotwrite, My White Kitchen, 47 Japanese Farms Through The Eyes of Its Rural Communities, Foodhoe, Chucks Eats, Things that Fizz & Stuff, Five Euro Food by Charles,Red Shallot Kitchen by Priscilla,With a Glass, Nami | Just One Cookbook, Peach Farm Studio, Clumsyfingers by Xethia, PepperBento,Adventures in Bento Making, American Bent, Beanbento, Bento No, Bento Wo Tsukurimashou, Cooking Cute, Eula, Hapabento , Happy Bento, Jacki’s Bento Blog, Kitchen Cow, Leggo My Obento, Le Petit Journal Bento & CO (French), Lunch In A Box,
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Must-see tasting websites:

-Sake: Tokyo Through The Drinking Glass, Tokyo Foodcast, Urban Sake, Sake World
-Wine: Palate To Pen, Warren Bobrow, Cellar Tours, Ancient Fire Wines Blog
-Beer: Good Beer & Country Boys, Another Pint, Please!
-Japanese Pottery to enjoy your favourite drinks: Yellin Yakimono Gallery