Fish lie low, oddly, in Hants river (7)

I believe the answer is:

teleost

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'fish' is the definition.
(I know that teleost is a type of bony fish)

I don't understand the remainder of the clue.

(Another definition for teleost that I've seen is " Bony fish such as herring or carp".)

I've seen this clue in The Guardian.

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