Will a tail fin grow back after part of it has been bitten off by another fish?

Yes, a tail fin can grow back after part of it has been bitten off by another fish. Fish have the ability to regenerate their fins and other damaged tissues. The rate of regeneration varies among different species of fish and depends on factors such as the severity of the injury, the fish's age and overall health, and the water temperature. In some cases, the regrown fin may not be identical to the original fin in terms of shape or size, but it is usually functional.