There are several methods of spawning fish that has many known and now it is common practice. The method of spawning naturally, spawning hdrmon with excitement, and methods Page (stripping).
A. Spawning naturally
After the culture to find and feed klorela especially rotifera prepared, the next step is to combine those memijahkan or fish. Candidates who have provided the parent must be obtained so that the eggs of good quality. The parent fish should be selected without a disability, sisiknya intact, and unharmed in the body and the fin-fin. Master-of the parent is detected. Selection is done in place of maintaining close. Master arrested with caution. To avoid damaged in the body of the fish, drain, which should be fine. One by one parent is inserted into the container capacity of 100 l and filled with sea water and given a drug such as polyethylene glikol monofenil ether, or clove oil as a spoon.
Determination of the female parent kanulasi done with the technique that is part of the gonad along with the lapse of 50 cm in diameter with 0,8-2 mm (using the hose to infuse the baby, known as a feeding or INFANT Pediatric Tube feeding. By the way, the end of hose is inserted into the hole sex The hole is located between the rectum and urine hole as deep as 10 cm, while the other end with diisap mouth. When the female fish in pairs, most eggs will terambil in the interval kanulasi so that the grain-grain visible and easily seen when moved to the item under glass microscope. If the water looks like liquid milk then it indicates that male fish in pairs. Fish in pairs male right-becul ready memijah (cooked gonad) will be issued genital sperm through the hole when the stomach is only slightly.
The size of adult fish depending on the type of fish. Grouper are generally hermafrodit protogeni that can be changed from male to be berina after melewad certain size. In the mud male parent can be found after reaching the size of approximately 11 kg, while the female parent size 3 - 4 kg have reached the level of maturity gonad. Move parent to parent-in-vessel spawning tanks, which were prepared with 1 male: 1 female. However, if the comparison is not possible then the number of female sex more.
Spawning fish, grouper and kakap should use naturally tub, a large vessel, which is 100-200 m3. The density of spawning fish in the tanks should be not more than
One of the techniques kanulasi perch
5 kg/m3 and running water per day at least 100%. For spawning fish beronang not need to use tanks, tanks for the big fish beronang memijah when the eggs will be attached to the substrate, especially on the bottom waters. Therefore, the special vessel to vessel-spawning fish beronang the bottom should be coated media substrate made to collect eggs. Pieces of plastic from the roof of the size of 25 cm x 25 cm or more can be used as the substrate / attached eggs. Pieces of the rope tied seutas with the sides so easily taken to be placed in the primary vessel to the meeting and sometimes the vessel walls are also necessary pieces of the roof. The eggs of spawning results will be embedded into the plastic substrate was the location can not be determined.
Figure 9. Bath spawning fish beronang (for the eggs attached)
Each day the parent-parent fish feed given the form of fish, shrimp, fresh enemy of 2-5% of the weight of fish. Beronang fish can also be given pellets of feed with protein content of 40%. Every day should be monitored, perhaps the fish have been memijah. Normally, spawning fish in the sea depends on circulation month. For example, the fish will kakap choose to light memijah months, while the grouper sunuk choose darker months. Time spawning usually occurs at night. Knowledge about the habits of fish is very memijah needs to be because this preparedness flyblow maintenance. Understanding memijah fish beronang habits, for example, required the installation of egg collectors.
When the spawning kakap and kept the collection of eggs can easily be done by means of egg collectors. Egg is then washed and moved to the incubation vessel. Beronang to fish, egg collection can be done by a rope so interesting substrate can be transferred directly into the vessel-vessel incubation. The number of eggs produced from the process depends on the weight of spawning fish, a female parent who memijah. In one spawning season, each individual female can produce millions of eggs.
source : Drs. Pramu Sunyoto
Dr. Mustahal, M.Sc
Penebar Swadaya
