Introduction

1. Introduction This Hatching Picture Tutorial is a product of the Catfish Hatchery of Abaflix Emerald Investment Ltd, Plot 6, Sanni-Luba Street, G.R.A, Ijebu-Ode and all rights reserve. If you wish to use or reproduce any of the pictures or thoughts here, kindly acknowledge us. For further details, information, training, clarification or consultation please contact us at abaflix@gmail.com or call Felix on 08034715121.

2. Brood stock Selection Catfish Hatchery starts with Brood stock selection. The females are in the grey bowl(4), while the males are in the pink bowl (2). The ratio of male to females can be varied. The females are checked to be gravid and injected with ovaprimat 5ml per kg. The males are also selected but both must be matured – 1 year old or more is safe .

3. Stripping of Eggs The females are stripped after a latency period depending on water temperature. These females were stripped after 9hrs at 27oC. Injected at 12am and stripped at 9am. The pictures show the stripping process and the mass of eggs in a clean, dry bowl. The female fish can be reused after 3 months and if gravid again. They are returned into brood tanks and proper care giving.

4. Getting the Sperm Digging out the sperm sac from the male. It is a messy process as the male was killed. We could surgically operate the male to remove the sperm sac too. In which case, the male can still go on to live and be reused in another 6 months but that require special care. The pictures show the digging out process, the sperm sacs in a plate and the cutting to release the sperms. Care should be taken not to let water touch it at this stage.

5. Fertilization Process Fertilization process, consists in the mixing of the sperm with the egg as shown in pic 1. The sperm is poured on to the egg. Clean water is then poured immediately as shown in pic 2 and quickly mixed thoroughly. Addition of the water activates the sperm and make them very active. The individual sperm cells fertilize the eggs by entering the micropyle within few seconds. The mixed fertilized egg is then ready for incubation.

6. The Hatchery Parts of my hatchery are shown above and the incubation net that the eggs will be spread on. Continuous water flow rates ranging from 1-2 litres per minute are used depending on the trough coupled with aeration. At this point also, we monitor and control water quality parameters such as water temperature, ph., Calcium Hardness and we treat the eggs with formalin to reduce the rate of fungal growth on the egg shells and on unhatched eggs.

7. Incubation The spreading of the eggs on the hatching nets in water is the incubation process. The eggs is spread in thin layers so that the hatchlings can easily drop out of the nets upon hatching. The pictures above show the spreading process and what it looks like after the spreading is done. The Incubation period is also water temperature dependent. We maintain a 28-30oC temperature and within 24 hrs. after they did hatch.

8. Hatch The pictures above shows still images of the hatched catfish hatchlings called fries. They are usually Golden green in colour and still carry egg yolk sac on their body. They are very sensitive to light and would be reared under dark conditions. They will absorb their yolk within 3 days , by then they would have turned black and their swimming becomes more erratic. What is left now is daily feeding, care and maintenance. The management of Catfish fry requires its own special skill set.