Touches fish (4)
I believe the answer is:
dabs
I believe this clue is a double definition.
'touches' is the first definition.
(dab is a kind of touch)
'fish' is the second definition.
(I've seen this before)
(Other definitions for dabs that I've seen before include "incriminating evidence, perhaps" , "fingerprint" , "finger traces" , "digitally recorded evidence" , "Fish < experts" .)