A shocking swimmer? (8,3)

I believe the answer is:

electric eel

I'm a little stuck... Click here to teach me more about this clue!

'a shocking swimmer?' is the definition.
(I've seen this in another clue)

'shocking swimmer?' is the wordplay.
'shocking' becomes 'electric' (I can't explain this - if you can you should believe this answer much more).
'swimmer?' becomes 'eel' (eel is a type of fish).
'electric'+'eel'='ELECTRIC EEL'

Can you help me to learn more?

(Other definitions for electric eel that I've seen before include "shocker" , "Shocking fish" .)

I've seen this clue in The Telegraph.

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