Air bladder also called,
What is air bladder?
Internal gas-filled organ
Contributes to the ability to control their
It acts as an accessory respiratory organ
It acts as a sound receptor and sound producer.
5. Location of swim bladder
It is located between the kidney
and alimentary canal, connected
with the esophagus and sometimes
it is also connected with the gill.
There are two types :
1. Physostomous swim bladder
(directly connected to the
gastro intestinal track)
2 . Physoclistous swim bladders
( not connected to the digestive
7. Basic structure
It’s consist of two layers
Tunica externa made up of dense collagenous fibrous
material. Its related to epidermis.
In the posterior chamber outside the layer of muscularis
mucosa there is a glandular layer which is richly supplied
with blood capillaries from rete-mirabile.
8. Shape and size of swim-bladder
The swim-bladder varies extensively in shape
and size such as-
1.Umbrina(oval shaped and without any
2.Atractoscion (only one pair of simple
3. Kathala (Develops a pair of appendage in
front of transverse septum into head)
4. Otolithoides (appendages attached to posterior
end main part lying parallel)
5. Johnius (hammer-shaped , 12 to 15 pairs
9. How do fish rise and sink in the water using air bladder?
To rise, a fish must reduce its overall
density by increasing its volume without
significantly increasing its mass and it
accomplishes the task by filling the air
bladder with air.
To sink it just releases the air in the air
bladder to reduce its overall volume and its
sinks in the water
10. Functions of swim-bladder
The swim-bladder in fishes performs a variety of functions.
1. Hydrostatic organ
2. Swim-bladder acts as adjustable float
3. Swim-bladder helps in respiration
4. Production of sound
5. Maintains proper center of gravity
Air bladder is very important for fish as it helps the
fish to maintain its bouncy.
The air bladder has evolved from the past ages to
It is also used in making of various kinds of dishes