Fish lake is an intricate biological system. It in propensities phytoplankton and zoo tiny fish on its surface (Epilimnion); different kinds of amphibian creature and the corpse of the dead in the segment water (thermocline or metalimnion); waste and rotting natural material in the base (hypolimnion). Various sorts of oceanic plants are seen up and down the edge of the lake. Most extreme abuse of the food and sea-going assets accessible in such a lake through the presentation of chose assortments of viable fish having distinctive taking care of propensities to accomplish high profitability is called composite fish culture or polyculture or blended fish culture or adjusted fish populace.
Points of Interest of Polyculture
1. Maximum usage of the assets accessible.
2. Different phases of a similar fish sp. Can be presented and refined when the regular feed accessible and its thickness are in bounty. This offices high efficiency.
3. As the efficiency and yield are more, benefit from such a culture us exceptionally reassuring.
4. Fishes chose must be profoundly viable with various taking care of propensities.
5. Market interest and dietary benefits are likewise to be mulled over during the fish choice.
6. Tolerance with the other living and non living life form of the lake by the fish to be chosen for composite fish culture ought to never be over looked.
7. Selected fish ought to have the option to live at various profundities of the lake other than the variety in their taking care of propensities. This forestalls rivalry among the living beings occupying a similar natural specialty.
8. Stocking thickness of the fish fry and fingerlings to be brought into a lake of one hectare must be painstakingly chosen. Generally500010,000 fingerlings are brought into a lake of one hectare water territory. Elements like fruitfulness limit, taking care of level, accessibility of the fingerlings, support limit of the lake, information about fish culture and so forth. Assume a significant job. As needs be, the loading thickness is to be determined.
9. Knowledge about the accessibility of regular feed and advantageous feed to be accommodated accomplishing high return is a lot of basic.
10. Information about the physic-compound elements impacting the development of fish ought to be known to the concerned rancher. He ought to set up the lake for fish culture a long time before the presentation of the chose species for accomplishing expanded efficiency
11. By knowing the underlying and last densities of the fish (by weight), one can gauge the yield. This encourages the rancher to investigate the traps and steps to be received for expanding the yield in ensuing harvests.
Supplementary Feed in The Composite Culture
Composite fish culture has been by and by in our nation since antiquated occasions. It has become an ordinary conventional practice to out ranchers. As yet following proportions proposed by theresearchers of this field to accomplish improved profitability.
Alikunhi et al proposed the proportion of 3:3:4 between Catla (surface feeder), Labeo (segment feeder) and mrigal (bottom feeder),
Horaandpillai (1962) proposed a proportion of3:6:1:or3:5:1 for the above fishes in polyculture procedure. They likewise recommended the presentation of Labeo calbasu a bottom feeder notwithstanding Mrigala their taking care of propensities are complete extraordinary.
Scientists directed at Cuttack held the proportion to be 5:3; 3:6, 8:2:3 for the fishes like grass carp, silver carp, Catla, Rohu, Scale fish, reflect carp and Tilapia.
Consolidated endeavors of CIFRI (Central Inland Fisheries Research Institute) and ICAR (Indian Council for Agricultural Research) brought about the proposition of following proportions to accomplish high return in brief timeframe.
5:3:8:2 – Grass carp, silver carp, Catla, Rohu, Scale carp and mirror carp.
5:3:6:8:2-Gras carp, silver carp, Catla, Rohu, scale fish and mirror carp.
5:3:3:6:8:2–Grasscarp, silvercarp, Catla, Rohu, Scalefish&mirror Carp.
As the fundamental carps feed upon accessible food, thickness of the normal feed diminishes gradually accordingly requesting the presentation of valuable feed.
Fish feed is set up from ground nut cake and rice wheat (or) cake animal dwellingplace, kitchen squander, vegetable waste(or)protein rich pupae of the silkworms or soya bean or notonectid bugs or prawn squanders or junk fish alongside required amounts of ‘B’- complex-nutrients. Yeast, cobalt chloride adequate supplements to the principle carps to develop brisk and yield high.
Hydrilla, Najasm Ceratophyllum, Chara, Napier Grass, Tapioca leaves, Kitchen Vegetables shelter and so forth can be given as advantageous feed to grass carps.
Subtleties of The yield from Polyculture
8-9 crease increment in the yield is accomplished from composite fish culture as upheld by the accompanying information.
As indicated by the exploration by CIFRI (1968) yearly yield from a lake was recorded at
With principle carps alone – 2088 kg/ha
With outlandish carps alone – 2900 kg/ha
With principle and fascinating carps through composite fish culture 3085 kg/had.
CIFRI (Cuttack) recorded a yearly yield of 9000, kg/ha/year from enormous tanks under composite culture. • Data got in1971byICARunitsinAndhraPradesh,Haryana, Maharashtra, Tamilnadu, attar Pradesh and West Bengal uncovered the half-yearly profitability under composite fish culture at 2692kg – 3210 kg/ha (Simla 1973). Efficiency recorded in the tanks of Karnalin Haryana Yield for a half year – 3448-5894 kg/ha. Yield for a very long time – 6191 – 7332 kg/ha. (Sukumaran – 1976) Grass carp puts on a load of 3 kg in one year under composite culture technique and contributed 30 % of the absolute yield.