Definition of "swim bladder" []

• See air bladder. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "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."