The selected male and female are kept in the brood stock tank. The female are selected and are induced with hormones, the commonly used hormone is the pituitary gland which are obtain from the base of the brain. The head is cut, the brain box is open, the pituitary gland is often found as a small whitish substance at the base of the brain. This is the mashed in pebble or plastic into a solution (using 9% physiological salt) which can be prepared by adding 9% salt into one litter of water.
These are then taken into the syringe and needle and are injected into the female fish above the lateral line into the female fish above the lateral line with the muscle.
Note that, the selected female must meet all necessary requirements for spawning.
The fish are then placed in a separate basin with little water on top of it -this water must not be too much, it must be kept alone aid separate to avoid in-fighting, brushes and unnecessary stress on the female fish. The female fish are kept alone for between 9-12 hours at 28C.
By the end of this period which is called latency period, the egg is said to have start running and ready to spawn.
At this point the male is incised laterally and the male reproductive organ called milt is removed and placed in a dry place.
Note: Under no circumstances should water touch the milt or the content of the milt.
Also, all that is requires for a successful spawning must be put into place before the male reproductive organ is removed. The tank must be prepared, the spawning net and all other necessary items.
The author is a fisheries biologist, author, trainer and fish farming consultant, read more on catfishfarming at [http://www.catfishfarmingbusiness/blog]
FERTILIZATION IN FINGERLINGS PRODUCTIONS
The male reproductive organ is then prepared. This is done by mixing of the male milt content with physiological salt solution (saline water). This is done by using scissors to incise the milt sac, squeeze the reproductive content (sperm) into already prepared saline solution, mixed gently and place aside.
The female eggs are obtained by a process called stripping. The eggs are stripped out by gently pressure the lower abdomen into a dry plastic container already prepared for the purpose. The eggs, collected are kept aside and water is not allowed to touch the content under any circumstances. The egg in milt are then mixed together, this is done by pouring the milt solution into the egg and then gently mixed together, after which a saline solution is used to rinsed the container containing the milt.
Pure clean water is added to the mixture and then gently stir to make sure all the mixture are thoroughly mixed together.
These are then spread on a spawning net. They should be evenly spread to avoid overlapping of the egg which can cause clogging and unhatched eggs.
They are left alone for 24 hours after which the egg would have hatched out and they are seen at the corner and at the bottom of the tank.
The net is then remove and either placed in another water/tank or they are washed away to avoid pollution.
The process of fertilization is a continuous process and all the process must be properly followed to the letter, negligence and absentism is hallmark of failure.Water quality plays a an important part in the success of the catfish farming and any other culture of other fish species