Can a fish fin grow back?

Yes, a fish fin can grow back, but it depends on the species and the type of fin. Some fish species have the ability to regenerate their fins, while others do not. Fish that can regenerate their fins usually do so if the fin is damaged or lost, but the process can take several weeks or even months. The new fin will typically grow back to its original shape and size, but it may not be as strong as the original fin. Fish that cannot regenerate their fins will typically have a permanent injury if their fin is damaged or lost.