The most common and most likely answer to this crossword clue is the 6 letter word MARLIN
M
A
R
L
I
N
More clues leading to the result MARLIN
- Fish right and left in the open sea
- Damage line, dropping latest oceanic fish
- Fish without a memory, hauled up
- Fish not a sausage male’s thrown back
- Both sides in principal
- Spoil lake popular for fish
- Spoil lake, home for fish
- Fish both ways in sea
- Fish left in sea, somewhat lacking?
- Most important to net river and lake fish
Buddy explains!

The straight part
We know that "fish" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fish = marlin.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 MARLIN mean?
MARLIN noun- Any species of game fish belonging to either of the genera Tetrapturus or Makaira. Every such species has a pointed, spear-like projection of the upper jaw.