Shrimp-like sea creatures (6)
I believe the answer is:
prawns
'shrimp-like sea creatures' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for prawns that I've seen before include "Small shrimp-like sea creature" , "Edible shellfish like large shrimps" , "Tasty shellfish - they're tasty in cocktails" , "Edible shellfish, nice in cocktail" , "Seafood" .)