Perhaps Ray thanks Ray? (5)
I believe the answer is:
manta
'ray?' is the definition.
(I know that manta is a type of ray)
'perhaps ray thanks' is the wordplay.
'perhaps ray' becomes 'man' (I can't explain this - if you can you should give a lot more credence to this answer).
'thanks' becomes 'ta' (UK informal version of 'thank you').
'man'+'ta'='MANTA'
Can you help me to learn more?
(Other definitions for manta that I've seen before include "Devilfish" , "Kind of ray" , "Giant ray" , "Large ray" .)