Would no bait on earth tempt them? (9)
I believe the answer is:
angelfish
'tempt them?' is the definition.
I can't judge whether this defines the answer.
'would no bait on earth' is the wordplay.
I cannot really see how this works, but
'no' could be 'n' (common abbreviation) and 'n' is present in the answer.
'earth' could be 'ge' (I've seen this in other clues) and 'ge' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for angelfish that I've seen before include "Brightly-coloured swimmer" , "shark" .)