INTRODUCTIONo Infusoria is a collective term for minute aquatic creatures such

as Ciliates, Euglenoids, Protozoa, unicellular algae and small invertebrates that exist in freshwater ponds. The term “infusoria” is often used to include all forms of microscopic life (animal and plant) .

o In modern formal classifications, the term is considered obsolete; the microorganisms previously included in the infusoria are mostly assigned to the kingdom Protista.

CONTD…..

o It is single cell protozoan belonging to family “ciliata” and grown in “green water”.

oThere are about 2000-3000 species of Infusoriaprotozoans which include Paramoecium , Blephoristha , Spirostomum , Volvox , Verticella .

Infusoria

CULTURE METHOD : -

The most easy & convenient method is described below:In a 500 ml conical flux, 300-350 ml boiled and cooled water is taken.

Add 2-3 ripe banana peels.

Cover the mouth of container tightly with nylon mosquito net to prevent the entry of mosquito and other insects.

Keep the container in a cool & light diffused place.

After 5-7 days (depending upon temperature and other environmental condition )The colour of the water will be hazy that indicates the developments of bacterioplankton (decomposers) which out of decomposition of the banana peels. Sometimes there may be appearance of slime like scum on the surface of the water.

Another 4-5 days later the water will turn clear and become transparent with light yellow colour.

Subsequently , the film of slime walls break up and disintegrates

The water is now heavily populated with Paramoecium & is ready for harvesting .

The culture will continue for 2-3 days if few drops of milk can be added to it.

Contd…….

INFUSORIA CULTURE

Culture tank

ADVANTAGE :

• The importance of infusoria to the aquarium culture is for feeding to the first feeding stage of ornamental fishes , they are small size raising from 25-300 um makes them ideal live food for young fry which are just consumed their yolk sac.

• Infusoria is very easily digested, so it is very important for growth of young fry.

IMPORTANT CILIATED PROTOZOANS

Ciliated protozoans may be important for first-feeding fish larvae because: 1) ciliates often dominate such communities and are more abundant than copepod nauplii in coastal waters; 2) most of the ciliates in the plankton are of a similar or smaller size than copepod nauplii . 3) protozoans can grow often just as well on inert foods, which is easier for aquaculture purposes marine ciliates are conventionally divided into loricate (tintinnid) and aloricate (naked) forms . naked ciliates may be more important food for fish larvae than tintinnids, because naked ciliates occur in considerably larger numbers than tintinnids .

THE ADVANTAGES OF FABREA SALINA• The advantages of Fabrea salina as an alternative for brine

shrimp larvae were summarized by De Winter, 1975 as follows:I) it is one of the few truly “pelagic” ciliates,

ii) it has the appropriate dimensions as a live food: depending on culturing conditions its size can vary from 50 - 500 μm,

iii) the smooth cell wall and the absence of appendages facilitate its uptake by the predators,

iv) the generation time is very short,

v) as a particle feeder it can be cultured on live algae as well as inert foods,

vi) according to the literature data its nutritional value for fish larvae seems to be excellent,

vii) as many other protozoans it forms a tough cyst membrane when submitted to unfavourable environmental conditions. The cysts can be kept viable for a certain period of time without losing their hatchability.

INFUSORIA CULTURE:

Generally, for infusoria culture, lettuce, cabbage and banana peels are commonly used as media as they stimulated growth of organisms.

1. Take a glass jar or aquarium, filled with de-chlorinated filtered water and add 2 to 3 banana peelings.

2. Cover the container with a cloth to prevent the entry of mosquitoes and files.

3. Keep the container in a cool place where natural diffused light is available.

4. After 2 to 3 days the water will turn milky and also emit foul smell. This is due to the multiplication of a large number of bacteria causing decay of banana peelings. A film of slime will be formed on the water surface.

5. In about 4 to 5 days, the water will turn clear, becoming transparent with light yellowish colour. This is because of the floating spores of infusoria in the air which have settled on the water surface break up and disintegrate.

6. The culture is now ready for feeding the early stages of fish larvae

CONT…..Once the culture reaches the peak density, it must be harvested, if not, the density will suddenly fall due to lack of space and oxygen depletion. After 50 % harvesting, add 2 to 3 drops of milk and again fill the glass jar with fresh water. The culture will sustain for a week. Infusoria can also be cultured by above method by putting bruised lettuce leaves or take some dry paddy husk and boiled it in water and take the solution for culture. Infousoria can be collected using 0.12 mm fine mesh cloth from foul smelling water bodies.