A lot of shrimp and urchin (5)

I believe the answer is:
scamp
'urchin' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'a lot of shrimp' is the wordplay.
I cannot really see how this works, but
'a' could be 'amp' (A is the symbol for the amp or ampere) and 'amp' is present in the answer.
'lot' could be 'c' and 'c' is found within the answer.
A single letter 's' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'and' acts as a link.
Can you help me to learn more?
(Other definitions for scamp that I've seen before include "Rogue - perform inadequately" , "pickle" , "Little Devil" , "A young rascal misbehaving in camps" , "Scallywag" .)
