Mirrored from Sudopedia, the Free Sudoku Reference Guide
Sashimi Fish is named after the Sashimi Observation made by Myth Jellies, and is a type of Finned Fish.
The writer noticed that a fish pattern does not need to be complete to perform the aimed eliminations. In fact, it is the absence of candidates that causes the eliminations, not the remaining candidates.
Another name for this type is skinny fish.
Compare the following patterns:
The cells with a diagonal line do not have a candidate for the selected digit. The X shows the candidates which form the fish pattern. The asterisks show which candidates can be eliminated. On the left, the remaining cells in rows 2, 5 and 8 will form a Finned Swordfish. On the right, it is not possible to form a complete Swordfish pattern because it will degenerate into a single in r2c2 and an X-Wing in columns 5 and 8. Combined, these will cause the same eliminations. The conclusion must be: An incomplete pattern has the same power as a complete pattern.
Sashimi fish patterns are more difficult to recognize than their finned counterparts, as they require you to complete the pattern in your mind.
Like all fish types, the names depend on the size of the pattern: