The most common and most likely answer to this crossword clue is the 6 letter word SCAMPI
I've seen this crossword clue in The Times
S
C
A
M
P
I
More clues leading to the result SCAMPI
- Seafood affected is taken back outside
- Sea creatures affected during island’s revolution
- Prawns swindle very good indeed
- Trick by Greek character providing sea food
- Seafood sensitivity initially affected one
- Swindle with pie lacking English seafood
- Rascal beginning to ingest breaded prawns
- Seafood is served up around military depot
- Con over a lot of baked food and Norway lobsters
- naughty boy takes one
Buddy explains!

The straight part
We know that "Sea creatures" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sea creatures = scampi.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SCAMPI mean?
SCAMPI noun- A Norway lobster (Nephrops norvegicus).
- Any similar species of genus Nephrops or similar prawns.