The most common and most likely answer to this crossword clue is the 5 letter word PRAWN
I've seen this crossword clue in Independent
P
R
A
W
N
More clues leading to the result PRAWN
- Shellfish that’s uncooked put into empty pan
- Man on board eating right seafood
- Seafood starters in posh restaurants aren't wholly nourishing
- Man on board catching river shellfish
- Something to eat when one of the minions entertains king?
- Man hides recipe for shellfish
- Partially chop raw Newquay seafood
- Initially named Wilson, actor recently playing rising swimmer
- Recipe in hand? Note cocktail ingredient
- A vegetarian won’t eat one quietly, not cooked, not its head
Buddy explains!

The straight part
We know that "shellfish" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case shellfish = prawn.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 PRAWN mean?
PRAWN noun- A crustacean of the suborder Dendrobranchiata.
- A crustacean sometimes confused with shrimp.
- A woman with a very toned body, but an unattractive face.
- A fool, an idiot.
- To fish for prawns.
- Pornography.
- (chiefly in the plural) A pornographic work.
- Material, usually visual, presenting something desirable in a sensational manner.
- Material that provides illicit gratification of an obsessive or unhealthy interest in something.