1. Choose only female fishes that weigh above 1kg.
2. Female fish should have a Well-rounded and soft abdomen.
3. Eggs, showing clearly the nucleus in the centre.
4. Genital opening is swollen and sometimes reddish or rose in colour.
5. When pressing out the female eggs for “inspecting” choose only the female fish that have eggs that separate from each other and are golden in colour
6. Make sure that the outlet where the egg of the female fish will come out is slightly dark in colour.
7. Make sure that the tummy of the female fish slightly protrudes out, when placed flat-faced down
1. Choose only male fishes that weigh above 1kg.
2. No clear external symptoms to indicate the maturity
3. Elongated and slender in body shape
4. Swollen urogenital papilla
5. Make sure the male organ “crosses” and its pink at the dot end.
Criteria For Choosing Male And Female Fish Brood Stock For Spawning
It is not every female fish with bulging stomach that has ripe egg for hatchery. The best way to know is through the genital papilla. The genital papilla will be swollen, pinkish or brown in colour. With this, you will know it has mature eggs. Female catfish genital papilla is shorter than that of the male. Choose only male and female fishes that weigh above 1kg so that the fries will also grow very fast. Some fish hatchers use broodstock of less than 1kg which is not good because the fries may not to grow well. You may come across green eggs during stripping. They are also good but the golden/light brown eggs are better. Even better than the pure black ones. Milt size is not weight-dependent in males. Tiny milt has been seen in males above 4kg, so you should understand that it's not by size.