Instinct breeding in natural environment is known as natural fish breeding. Naturally in favorable environment of tide stream, a hormone of fish inside their body named gonadotropin get mixed with blood and incite the fish for breeding. The breeding period of most of the fishes is May to August. This is the breeding period of rui, katla, mrigal, grass carp, bighead carp, catfish, pumpti etc. Winter season is also breeding period of some fish species like common carp. Any day is not favorable for fish breeding. The fish breeding depends on some aspects which are listed below.
- Type of stream
Those aspects influence the breeding of fish. Monsoon, cloudy sky, mild wind and a day with cold weather is very suitable for fish breeding and laying eggs. Any days with cold weather between eleventh to full moon or new moon is ideal for breeding. The suitable temperature of for fish breeding is 28°-31°c. The main source of natural breeding of fish is rivers. In breeding season adult female fish swim towards or against tide and the male fish follow it. And they mate together in a little tide (flooded area) area. After that the female fish lays eggs in the water and male fish release sperm instantly over the eggs. As a result the eggs become fertile and minnow come out from the eggs within a few hours. This system is simply known as natural breeding.
Natural Breeding Places of Some Fish
- The major places of natural breeding of fish is river, swamp, bill, flooded land, outfall and coastal area where tide is available.
- Wide natural breeding place of carp fish like rui, katla, mrigal etc. is small or big sized rivers.
- Breeding source of taki, shol, koi, pabda, moda, common carp etc. is stagnant stream.