Swordfish and Jellyfish

For a digit, find three rows in which its candidates lie within the same three columns (each row may use two or three of them). Then the digit must be placed once in each of these columns in these rows, so you can remove it from all other cells of the three columns.

A Jellyfish does the same with four rows and four columns. Larger fish exist but are rarely needed, since a smaller pattern from the opposite direction usually exists as well.

Notation

Swordfish: 8 can be removed from r3c3.