1, look at the belly: observe the belly of the black Mary fish is a good way to determine whether it is pregnant. Because it is an ovoviviparous fish, fertilization is internal fertilization. So after pregnancy, their bellies will become significantly larger. If the belly of the female fish is obviously enlarged, then it is likely to be pregnant.
2. Look at the cloaca: If the belly of the Mary fish becomes very big, you can look at its cloaca again. The cloaca of the pregnant female turns white 2-5 days before the birth of the baby fish. And the closer you get to the time of birth, the whiter the cloaca becomes. If the cloaca of the mother fish is significantly whitened, it indicates that the baby fish is about to be born.
3. Habits: After pregnancy, the female black Mary fish will stay away from the school of fish, actively alienate other fish close to her, decrease vitality, and like to stay in a daze in the corner. They also swim slower. These manifestations can be used as an auxiliary basis to determine whether it is pregnant.
The black Mary fish can only start to reproduce after 5-6 months of growth. At this time, they are sexually mature, as a parent fish to reproduce small fish is completely no problem. However, at this time, their reproductive capacity is still relatively low, only 10-50 small fish can be born at a time. When they get bigger, they can produce more small fish each time they reproduce.
