Dictionary of Ichthyology  

hancho hocho = in Japanese 半丁包丁 (half-tool knife), the shorter of two blades used to fillet tuna and other large fishes. The blade is about 1 m long. See also oroshi hocho.

Tsukiji Fish Market from Wikimedia Commons: http://commons.wikimedia.org/wiki/File:HanchoHocho.Tsukiji.CR.jpg

Canadian Museum of Nature
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