Market always has salmon (4)

I believe the answer is:

keta

I'm a little stuck... Click here to teach me more about this clue!

'salmon' is the definition.
I don't know anything about this answer so I can't judge whether this works.

'market always has' is the wordplay.
'has' indicates a hidden word.
'KETA' is hidden in the letters of 'market always'.

Can you help me to learn more?

(Another definition for keta that I've seen is " Fish".)

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