The document discusses the swim bladder, or air bladder, of fish. It is an internal gas-filled organ that contributes to a fish's ability to control buoyancy. There are two types - physostomous, which is directly connected to the digestive tract, and physoclistous, which is not connected. The basic structure includes a sac-like shape with two layers, an epidermis and endodermis. The swim bladder varies in shape and size between fish species and allows fish to rise and sink in water by increasing or decreasing the volume of gas inside without changing mass. Its key functions are to act as a hydrostatic organ, adjustable float, aid in respiration, produce sound, and maintain the fish's

1. Welcome to
My
Presentation

2. My presentation topic is on
Swim bladder of fish

3. Introduction
Air bladder also called,
swim-bladder,
gas-bladder and
fish maw.
What is air bladder?
 Internal gas-filled organ
 Contributes to the ability to control their
buoyancy
 It acts as an accessory respiratory organ
 It acts as a sound receptor and sound producer.

4. Air bladder

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.

6. Types
There are two types :
1. Physostomous swim bladder
(directly connected to the
gastro intestinal track)
2 . Physoclistous swim bladders
( not connected to the digestive
tract )
Type-1
Type-2

7. Basic structure
 Sac-like structure
 It’s consist of two layers
1. Epidermis
2. Endodermis
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
appendage)
2.Atractoscion (only one pair of simple
diverticula)
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
arborescent appendages)

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

11. Conclusion
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
the present
It is also used in making of various kinds of dishes