VPP 322: Aquatic Animal Diseases, Health Care and Management (1+1)

Composite fish culture techniques

COMPOSITE FISH CULTURE

Aim: To study the principles of composite fish culture.

• Composite fish culture is the combined culture of different species of fishes with different feeding habits in a production system.
• A fish pond is a complex ecosystem as the surface is occupied by the floating organisms such as phyto and zooplankton, the column region has live and dead organic matter and the marginal areas harbour a variety of aquatic vegetation. In composite fish culture, the different trophic levels of a pond are utilized by stocking compatible species of fishes with different feeding habits to exploit all types of food available in different regions of fish pond to maximize food production.
• The common species of fishes that are cultured in composite method and their feeding habits

No	Species of fish	Feeding habit
1	Catla catla (catla)	Surface feeder- feeds on phytoplankton and zooplankton
2	Labeo rohita (rohu)	Column feeder-feeds on phytoplankton, plant debris of aquatic plants
3	Cirrhinus mrigala (mrigal)	Bottom feeder-feeds on decaying organic debris.
4	Hypophthalmichthys molitrix (silver carp)	Surface feeder-feeds on phytoplankton
5	Cyprinus carpio (Common carp)	Omnivorous bottom feeder
6	Ptenopharyngodon idella (grass carp)	Feeds on aquatic weeds and terrestrial grass

• Other species of fishes that could be included in a composite fish culture system are freshwater prawns, catfishes and murrels.

Preparation of pond : Refer Chapter 8, nursey pond preparation  

Stocking

• A stocking density of 5000-10,000 fingerlings/ha can be followed. The stocking percentage of different species is shown in Table.

Type of fish	4 species combination	5 species combination	6 species combination
Catla (%)	30	30	10
Rohu (%)	15	15	15
Mrigal (%)	30	25	20
Common carp (%)	25	20	20
Silver carp (%)	-	-	25
Grass carp (%)	-	10	10

Feeding

• Supplementary feeding is done with a mixture of rice bran and ground nut oil cake, chopped tender aquatic weeds (Hydrilla sp., Ceratophyllum sp.), vegetable and kitchen waste. Feeding rate is 3-4 % of the fish biomass which can be adjusted according to the growth of fishes. Feeding can be done twice a day.

Production

• An individual growth of approximately one kg/fish is reached in 10-12 months. A total yield of 8-10 /tonnes/ha/year is obtained in composite fish culture.