From Sudopedia, the free Sudoku reference guide

From Sudopedia

When fish are no longer restricted to rows and columns, strange varieties emerge. When either the defining set or the secondary set contains a mixture of rows, columns and/or boxes, these fish are classified as mutant fish.

There are no mutant X-Wings, because the interaction between a single box and line is fully covered by the Locked Candidates technique.

Here is a fish diagram of a Mutant Swordfish, with the defining set consisting of 2 rows and 1 column, and the secondary set containing 1 column and 2 boxes.

Mutant fish can also be found in finned variations.

See Also

• Fish
• Franken Fish
• Mutant Swordfish
• Mutant Jellyfish