Jack Sprat's catch? (8)

I believe the answer is:

mackerel

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'jack sprat's catch?' is the definition.
The definition and answer can be both animals as well as being singular nouns.
Perhaps you can see an association between them that I can't see?

This is all the clue.

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(Other definitions for mackerel that I've seen before include "Banded food fish" , "Commonly-eaten fish" , "that's fishy" , "Common striped fish, very tasty" , "Sea fish" .)

I've seen this clue in The Globe and Mail.

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