CULTURE OF INFUSORIA
Aman Singh1, Ekta Singh1, O.P. Sharma2,V.P. Saini2
1Research Scholar, College of Fisheries, Guru Govind Singh Marg, MPUAT, Udaipur- 313001(India), m: 91-9587845952
2Professor, College of Fisheries, Govind Singh Marg, MPUAT, Udaipur- 313001(India),
Corresponding author: email@example.com
INTRODUCTION:- Successful production of seed of fin fishes and shell fish spp. in hatcheries mainly depends on the supply of proper live food organisms at the proper time. Live food organisms in this respect serve as "Living capsules of nutrition". Infusoria is the most primitive of all the animals of animal kingdom. Besides, they are small in size, nutritionally rich and soft bodied. Owing to these qualities they are a starter feed for early stages of fin fishes and shell fishes in hatcheries.
TAXONOMIC POSITION:- The tiny microscopic singled celled animalcules collectively called 'Infusoria' belong to the class ciliate and phylum protozoa.
HABIT AND HABITAT:- Infusoria inhabit ponds and tanks of fresh water, brackish water and marine water habitats having decaying weeds, organic matter and foul smelling debris.
FOOD AND FEEDING:- Infusoria feeds upon micro-organisms such as bacteria, algae and also on debris. Nutrition is 'Holozoic'. Cilia present on the body act as chief locomotory organ and food catching organelles.
REPRODUCTION:- These are of two types i.e. asexual and sexual. Asexual reproduction occurs by binary fission and sexual by conjugation.
The most common are paramecium, stylonchia. These organisms are culture by several methods:-
Using banana pealing: - Keep banana pealings in a big jar or glass aquarium containing about 50 liters of water. Cover the container with cloth which will prevent the entry of mosquitoes and flies, but will allow the entry of air. Keep the container in a cool place where natural air is available. In 1-2 days the water becomes milky and emits a foul smell. This is due to multiplication of the large number of bacteria causing decay of banana pealings. A film of slime will be formed on the water surface. In about 4-5 days the water will turn clear become transparent with light yellowish colour. This is because of the floating spores of Infusoria in the air which have settled on the water feeding on bacteria which multiplies in large numbers. Subsequently, the film of the slime on the water surface breaks up and disintegrates. The culture is then ready for early stage feeding of the fish larvae. Once the culture reaches its peak density it must be harvested. If not, the density will suddenly fall due to lack of space and oxygen depletion. The culture will sustain itself up to 2-3 weeks if a few drops of milk are added.
By using hay infusion: - Take dry hay infusion into a dry pan and pour boiling water over it. Transfer the hay water into the jar or aquarium. After this repeat the process as described under banana pealing methods.
By using lettuce leaves: - In place of hay, lettuce leaves can also be used in culture. After this follow the same process as banana pealing.
By using milk and milk products: - Add a teaspoon of milk or two pinches of milk powder to the culture tank. Thereafter follow the same process.
By using apple snail: - keep the apple snail (Ampullaria globosa) in aquarium and feed it with lettuce leaves or hydrilla. The droppings (faecal) will contain half digested leaves and will give rise to a large population of Infusoria when added to the water. In order to provide a continous supply of Infusoria it is desirable to maintain Infusoria in batch culture.
B. MARINE INFUSORIA
1. Fabrea salina: - Is a marine pelagic form found in floating form in stagnant marine water bodies. It is a euryhaline micro-organism, it grows and reproduces over a wide range of temperature (5-40 C) and salinity (up to 100ppt). It can be cultured on various feeds (fermented wheat flour). The best results are observed at 40-65ppt and 35 to 45 C temperatures. The generation period is 20-22 hours.
2. Euplotes spp.: - It is a saline benthic organism also found in stagnant water where there is accumulation of decaying organic matter. The best results may be obtained at 35ppt salinity and 20-25 C temperature.
Infusorians are photo static. In the presence of light, they come onto the surface at a high density and can be seen as film or a cluster on the water surface. They are scooped with fine mesh nets of 50-100 micro meters bolting silk cloth. Generation period of Euplotes spp. is 10-12 hours.
After harvest thorough washing is needed prior to feeding the early stages of fin fish and shell fishes.