swimming-bladder

swimming-bladder

A fish uses its swimming-bladder to control its depth in the water.

Definition
  1. Noun:
    • A gas-filled sac in fish: The "swimming-bladder" (also known as the swim bladder) is a buoyancy organ found in most bony fish. It is a flexible, gas-filled sac located in the body cavity, which helps the fish control its vertical position in the water without expending energy.
Usage Examples
  • Noun:
    • The fish's swimming-bladder allows it to float at different depths without swimming constantly. (The gas-filled sac provides neutral buoyancy.)
    • Damage to the swimming-bladder can cause a fish to sink or swim awkwardly. (Injury to this organ affects the fish's ability to stay upright.)
Advanced Usage
  • "to have a ruptured swimming-bladder": a condition where the sac is damaged, leading to loss of buoyancy control.

    • After the rough handling, the aquarium fish had a ruptured swimming-bladder and floated upside down. (The sac was torn, causing imbalance.)
  • "swimming-bladder inflation": the process by which a fish fills its swimming-bladder with gas (often from the surrounding water or from its own blood).

    • Young fish must gulp air at the surface to achieve initial swimming-bladder inflation. (They need to take in air to fill the sac.)
Variants and Related Words
  • Swim bladder (n): an alternative name for the swimming-bladder, often used interchangeably.

    • The swim bladder is homologous to the lungs of land vertebrates. (The organ shares an evolutionary origin with lungs.)
  • Bladder (n): a general term for a sac in the body that holds fluid or gas (e.g., the urinary bladder).

    • The fish's bladder is specialized for buoyancy. (Its sac has a specific function.)
Synonyms
  • Gas bladder: a scientific term emphasizing the gas-filled nature of the organ.

    • The gas bladder is essential for deep-sea fish to maintain depth. (The sac is crucial for pressure regulation.)
  • Air bladder: a less formal synonym, especially used in historical or non-specialist contexts.

    • The air bladder helps the fish rise and descend. (The sac aids movement in the water column.)
Related Idioms