air bladder

noun

: a sac containing gas and especially air

The float tube was an ingenious device built around an inner tube, featuring a seat and backrest created from an additional air bladder in the nylon shell of the rig.

—Peter Bodo

: such as

a

: a saclike organ present in most bony fishes which contains gas and especially oxygen and nitrogen and that serves chiefly to control buoyancy and in some primitive fish (such as the lungfish) functions as an accessory respiratory organ

Elasmobranchs lack the air bladder that gives other fishes buoyancy, and their skeletons are made of light cartilage instead of bone.

—Steve Kemper

Fish make sounds by clicking their teeth, blowing air, and drumming with special muscles against tuned inflated air bladders.

—Lewis Thomas

called also swim bladder

b

: a gas- or air-filled vesicle in certain algae and aquatic plants (such as rockweed) that helps keep photosynthetic blades and fronds buoyant

At the base of each frond is a small air bladder that buoys the blade up to the surface, where it continues to grow while forming a dense canopy approximately 4 feet deep.

—Jennifer Winger

called also pneumatocyst

Illustration of air bladder

• A air bladder

Examples of air bladder in a Sentence

Recent Examples on the Web

For such a lightweight pillow, the Aeros Premium has plenty of features like a knit polyester exterior, a contoured TPU air bladder that mimics a standard pillow, and a proprietary valve for maximum air fill customizing. —Maggie Slepian, Travel + Leisure, 17 June 2024

It’s made with a light layer of synthetic insulation and an air bladder that doesn’t give you that uncomfortable sleeping-on-a-beach-ball feeling. —Sarah Kester, Travel + Leisure, 29 Aug. 2023

Up close, Sargassum is a collection of leafy structures, branches, and oxygen-carrying berries called pneumatocysts, air bladders that help the mats float. —George Petras, USA TODAY, 20 Mar. 2023

Blowers then inflate an air bladder to help seal the gap—this can only be done once the roof has stopped moving. —Tim Newcomb, Popular Mechanics, 29 Aug. 2022

In 2007, Herbert Nitsch, a 41-year-old Austrian, dove more than 700 feet—assisted by a watersled on the way down and an air bladder to pull him to the surface—to claim a new world record for absolute depth. —James Nestor, Outside Online, 25 Jan. 2012

The fish’s thick, spongy, and highly vascular air bladder behaves like a lung to aerate the alligator gar’s blood. —National Geographic, 25 Feb. 2020

Species such as snappers and groupers have air bladders, which allow them to make fine-scale adjustments in their buoyancy. —Popular Science, 11 Feb. 2020

The paper was made of cloth, sometimes silk and isinglass, which is somewhat see-through and made from fish air bladders. —Jonah Estess, The Conversation, 29 Aug. 2019

Word History

First Known Use

1675, in the meaning defined above

Kids Definition

air bladder

noun

1

: swim bladder

2

: a cavity found in various algae that contains gases and serves to keep the algae afloat