DEVELOPMENT AND HATCHING TYPES EGGS OF SEA FISH
Principles hatchery collects the eggs and then move them into the sedimentation tanks, hatchery and maintenance. Flyblow to be able to produce good quality fish that the incubation process must be done with caution.
A. Egg incubation
Egg incubation aims to create conditions so that progress with the development of the fetus so that the flyblow good quality. Eggs that have muzaphar floating nature of the results of spawning naturally or by artificial (striping) put in a fine net bag.
Net bag can be made from cloth, a fine or a plankton net with a diameter less than the net eye diameter of eggs. Place the bag of eggs can be used for this purpose.
Net bag is inserted into the vessel capacity-bak round 0.5 - 1 m3 of sea water filter (clean water). Sea water used is always flowing at a rate of 20 1/menit continue to occur so that the running water. Aeration is also not too strong given that the eggs can be spread evenly. Eggs that will die in the bottom sediment bag nets and disipon periodically. Usually the eggs results of artificial insemination has a high death rate.
Incubation eggs made for 1 - 2 hours before the eggs hatch and start this depends on the type of fish. When viewed in Microscopic, embryo development for each type of fish eggs this looks the same. The development of the embryo starts from a single cell, which then split into two cells, four cells, eight cells, and so on until the cells formed many agencies that eventually formed flyblow. Time required for the establishment of this body flyblow depending on the type of fish and water temperature. That has been fertilized eggs will be coated by a strong membrane. With the help of the microscope, it looks different when compared with egg
TABLE 2. Diameter OF EGGS AND OIL ON BUTIRAN OF EGGS, AND length of the incubation period longer hatch flyblow NEW FISH ON DIFFERENT TYPES
| Jenis Ikan | Diameter telur (mm) | Diameter Butir minyak pada telur (mm) | Masa Inkubasi (jam) | Panjang larva baru menetas (mm) |
| Kerapu macam Epinephelus Fuscoguttatus Kerapu lumpur Epinephelus suillus Kerapu Sunuk Plectropomus Maculatus Kakap Jenaha Lutjanus johni Kakap bakau Lutjanus Argentimaculatus Kakap putih Lates calcarifer Kakap mata kucing Psammoperca Waigiensis Beronang Siganus spp. | 0,89 0,90 0,80 0,80 0,79 0,78 – 0,81 0,70 – 0,80 0,54 – 0,55 | 0,10 - 0,18 0,16 0,15 0,23 0,18 banyak | 18 16 – 25 16 – 18 14,5 – 15,0 17,0 – 17,5 15 – 17 14 – 16 13 20 - 26 | 1,34 1,5 – 1,9 1,59 1,6 – 1,7 1,6 – 1,9 1,6 1,76 1,98 – 2,1 |
Figure 12. Development of eggs to a fish embryo mud
that is not fertilized. For fish eggs beronang that has attached the collector-egg collectors can be directly transferred to the vessel, the vessel as the incubation once the vessel maintenance flyblow.
Eggs have a new conception will form a cell and bring grain oil. Eggs and grouper fish will kakap bring a morsel of oil, while fish eggs beronang usually take more than a grain size of the oil is not uniform. The amount of oil droplets in the egg beronang this will be lost during the incubation process until the eggs hatch.
Flyblow the new hatch usually carry only one or two eggs in oil. The development of eggs and then start from one cell split into 2 and 4 cells, 16 cells, and so on until the stadium-formed fetus stadium. Development of eggs to hatch and formed embryo into flyblow will depend on the species and the incubation temperature of the water.
Figure 13. The development of egg to embryo to be kakap
Lutjanus argentimaculatus
Beronang fish eggs taken from the substrate take five grains of oil
source: Drs. Pramu Sunyoto
Dr. Mustahal, M. Sc
Sower Swadaya
