This is a PDF of my presentation I have done during my BSc final semester. My presentation is on Rotifér Culture by Stock culture procedure.

1. ROTIFER CULTURE
-A PERFECT DISH FOR FISH
PRESENTED BY :-
Md. Shorab Alam
BSc 6th Semester, Zoology (H)
Supervisor:-
Dr. Sk Kabita
Assistant Professor
Departmentof BiologicalSciences
Aliah University,Kolkata
2021

2. CONTENT:-
• Introduction
• Commonly used species
• Why Rotifer’s ?
• Why Stock Culture ?
• Materials required
• Conditions required
• Procedure
• Importance of Rotifer as fish feed
• Conclusion
• Reference & Acknowledgement

3. • Rotifers are small (50-1000 µm) zooplankton that occur in freshwater,
brackish,and marine environments.
• Rotifers feed on microalgaeand are consumed by a wide variety of fish,
shellfish,corals,and other organisms.
• The marine rotifer,Brachionus plicatilis,is an important food organisms
for the first feeding stages of larval marine animals around the world.
• Feed types vary,but the most common are algae such as Tetraselmis,
Chlorella and Isochrysis.
• Other’s include baker’s and torula yeast,fish oil and artificial diets.
INTRODUCTION:-

4. COMMONLY USED SPECIES:-
B.Plicatilis (Large
strain)
Size:- 171 – 238um
Low-temperatures
20-25° C
Euryhaline
B.rotundiformis (Small
strain)
Size:- 121 – 162um
High-temperatures
28- 35° C
Low-Salinities

5. WHY ROTIFER’S ??
• The level of polyunsaturated ω-3 fatty acid in rotifer is believed to affect both
survival and growth rate of fish larvae.
• Rotifer transmits adequate supplies of micro and macronutrients,vitamins and
even antibodies to fish larvae.
• Their Small size and slow swimming velocity makes them a suitable prey for fish
larvae.
• Very high reproduction rate.
• Yields larger quantities of live food in a very short period of time.
• Easy to Culture.
• They also may be used as biological pollution indicators.

6. WHY STOCK CULTURE? :-
• Culturing large volume of rotifer’s on bakers yeast,algae always involve
some risks of mortality on the population.
• In order to minimize the risk,Stock Culture are generally performed in
isolated room to prevent contamination with bacteria or other ciliates.
• These Stock Culture generates large population of rotifer’s as fast as
possible and maintained on algae like chlorella.
• The water of the rotifer’s being completely renewed regularly and easily
because of small scale.

7. MATERIALS REQUIRED:-
1. Rotifer eggs (from Pond water),
2. Zooplankton net (50- 100 micron),
3. Plastic Jars (5 Litre size),
4. Compound microscope,
5. Fresh Chlorella/ dried Chlorella / baker’s yeast.
(Rotifer feed)

8. • FOR PREPARING DRIED CHLORELLA:-
• Pulse bran (150 g),
• 5 litre tap water,
• Pond water,
• Plastic bucket- 3pc,
• 10gm lime,H₂SO4,
• Test tube (10ml),Conical flask (200ml,500ml) , beaker.
• Autoclave,centrifuge machine,Refrigerator,microwave Oven,
• Mortar & Pestle,Dropper.

9. • CONDITIONS REQUIRED :-
(For optimal growth of Rotifer)
• Temperature= 20-30°C.
• Salinity = 10-25 ppt (parts per thousand).
• pH= 6-8.
• Dissolved O₂ = 5-7 ppm.
• UnionizedAmmonia level = NH₄ < 20 ppm; NH₃ < 1
ppm

10. PROCEDURE (STOCK CULTURE) : -
• Collect Brachionus plicatilis (large-strain) rotifer from the stagnant salt water with a scoop net
having 50-100 micron mesh,
• Dilute the sample by adding fresh clear water having salinity as that of sample,
• Examine the samples under stereozoom microscope and pickup rotifer with fine dropper and
inoculate in a 10ml glass tube containing 5mlWater.
• Feed them with Chlorella live or dried at 200ppm at a cell density of 10 x 106 cells per ml.
• Serially dilute the cultures test tube daily through several large tube of 20ml containing 10 ml
of water.
• Gradually increase the volume to 50-100ml capacity beaker and then 0 to 1-2litre to get a
density of 100-150 individuals per ml.

11. ROTIFER’S IMPORTANCE AS FISH FEED:-
• Larvae are first fed on a small strain of rotifers,and as larvae
increase in size, a larger strain of rotifers is introduced.
• Rotifers are regarded as living food capsules for transferring
nutrients to fish larvae.
• These nutrients include highly unsaturated fatty acids (mainly 20:5
n−3 and 22:6 n−3) essential for survival of marine fish larvae.
• Optimal size for fish larvae,shellfish,corals and other filter feeders.
• They are buoyant which assures optimal availability for larvae,slowly
swimming and sessile animals.

12. CONCLUSION:-
• There are many ways to culture Rotifer like Stock Culture (Small quantity) and mass
Culture (greater quantity).
• Keep Culture containers andWater Clean.
• Control contaminants such as ciliates and bacteria using disinfectant.
• Harvest daily to maintain the Culture in growth phase.
• Add some algae regularly even a small amount.
• Need to feed after every 4 hours.
• Rotifer’s are filter feeders.
• They are considered as very importantfish feed worldwide.

13. REFERENCES:-
• A text book of Fish and Fishery science – C. B. L. Srivastava.
• An introduction to fishes- S. S. Khanna.
• The Males of the Rotifera – C.Wesenberg.
• Google search engine-
• https://www.fao.org/3/W3732E/w3732e0h.html
• https://youtu.be/J_Uuev-Xxb
• https://www.researchgate.net/publication/230803529_Methods_for_Culturing_Saltwater_R
otifers_Brachionus_plicatilis_for_Rearing_Larval_Zebrafish