Catch ten wriggling fish (8)
I believe the answer is:
entangle
'catch' is the definition.
(I've seen this before)
'ten wriggling fish' is the wordplay.
'wriggling' is an anagram indicator.
'fish' becomes 'angle' (angling is a kind of fishing).
'ten' is an anagram of 'ent'.
'ent'+'angle'='ENTANGLE'
(Other definitions for entangle that I've seen before include "Create confusion" , "snarl" , "Involve in complicated circumstances" , "Ravel" , "catch" .)