from The American Heritage® Dictionary of the English Language, 4th Edition
- n. See air bladder.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A gas-filled sac within the bodies of most fish that variously acts as a float, lung, sound-producing organ or an aid to hearing.
from the GNU version of the Collaborative International Dictionary of English
- n. an air bladder of a fish.
from The Century Dictionary and Cyclopedia
- n. Same as swimming-bladder.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. an air-filled sac near the spinal column in many fishes that helps maintain buoyancy
Sorry, no etymologies found.
Manatees and dugongs float effortlessly in hydrostatic equilibrium, not by means of a swim bladder as fish do see below, but through being equipped with heavy bones as a counterweight to the natural buoyancy of their blubber.
The swim bladder is perhaps the major key to the teleosts’ success, and it is well worth a digression to explain it.