Inflatable Ball, Swim Organ That Fish Use to Float

This page is the CodyCross answer for the clue below from The Netherlands, Group 2109, Puzzle 4 (Eindhoven University).

Question is: Inflatable Ball, Swim Organ That Fish Use to Float

and the answer is: BLADDER

Word Meaning:

BLADDER — (zoology) A flexible sac that can expand and contract and that holds liquids or gases.

Definitions from Wiktionary.

Inflatable Ball, Swim Organ That Fish Use To Float - The Netherlands CodyCross Answers | CodyCross Solutions