1. Reason: The blackening of the carapace of Brazilian tortoise may be caused by soft nail disease, which is mostly caused by lack of light or calcium deficiency. When their shells turn black, they will also soften, and finally their shells will rot.

2. Solution: Breeders need to give them more sunshine. If they can't get natural light, they can use UVB lamps instead of sunlight. In addition to getting more sunshine, we should also feed more foods with high calcium content. Such as small fish, shrimp, etc. If calcium deficiency is serious, you can also feed some cuttlefish bone meal.

1. Reason: The shell of Brazilian tortoise turns black, and it may also be suffering from shell rot. It is mainly caused by poor water quality or bacterial infection. After the appearance of rot, the carapace will appear black pieces.

2. Solution: Breeders need to ensure that the water quality is clean, and chlortetracycline should be applied to the rotten armor. If the rotten armor is serious, it is necessary to fish out the Brazilian tortoise and raise it dry. Besides smearing chlortetracycline, anti-inflammatory drugs such as amoxicillin and penicillin should be added to the food.

1. Reason: The black shell of Brazilian tortoise may also be due to the darker color of the container, and Brazilian tortoise will change its own color according to the change of surrounding environment. If the color of the container is darker, the color of their carapace will also become darker.

2. Solution: Breeders can try to change containers and give them more sun, so as to change their body color.