The process of fin regeneration begins with the formation of a blood clot at the site of the injury. This blood clot provides a foundation for new cells to grow. Over time, these new cells will develop into a new fin.
The rate at which a molly's fin grows back depends on several factors, including the severity of the injury, the water quality, and the overall health of the fish. In general, it takes about 2-4 weeks for a molly's fin to fully grow back.
It is important to keep the water quality high during the fin regeneration process. This will help to prevent infection and promote healing. You can also add aquarium salt to the water, which will help to reduce stress and promote healing.
If the injury is severe, you may need to medicate the fish with an antibiotic to prevent infection. You can also place the fish in a quarantine tank to prevent it from being bullied by other fish.
With proper care, a molly's fin can fully grow back after being torn or eaten by another fish.