October 22, 2008

Nursing of 1-2 inches soon hock

Marbled goby in commercial culture have a few distinct culturing stages. These culturing stages are required due to the cannabalistic nature of the fish. Stage 1 involve selection of spawners, providing spawner with the necessary vitamin, spawning, collecting and hatching of eggs, and feeding the larvae for the fish two months. This process will not be discussed here because its a trade secret that involve alot of sleepless night of actually try and error. Stage two involve growing the fish frys from month 3 to month 5 ie from 1-2 inches (4-6cm) to 5 - 6 inches.

1 day eggs

2 days old frys

2 weeks old fry

1 month old fry2 months old fish2 months old fish

At this stage the fish is not only canabalistic but are just killers at large. They kill by instinct. They involve in the strategy of less mouth more food. Cannot help it since in nature, food have to be hunted and excess food cannot be kept in ice boxes. This also a stage where we change the diet of the fish from totally natural food to formulated food.

2 months old fish

Firstly, the density of culturing the fish at this stage is about 500-700 pieces in 1 meter cube of water. Water maybe freshwater or slighty brackish up to 5-6ppt. The the water should be about 400-600 cm deep and air lift is used to provide oxygen in the water. Do remember that marbled goby is not an air breeeder and oxygen level of at lest 5 ppm is good for the fish. As for food, the combination of sinking started shrimp pellet with a dose of squid oil and live rice shrimp will be good. 2 days of shrimp pellet and one day of rice shrimp will help the fish to grow to about 4-6 inches in 3 months.

2 months old fish

If the nursery is a bit tight interm floor space or the fish is growing too fast, grading should be done every 4 week. However, if the growth is about even, grading should be done at the end of 2 months. The mortality rate during this stage is about 30-40% due to nature and cannabalism.

At the end of this stage, the fish can be grown in grow out tank and feed formulated food totally.


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