The barbels do not grow back to the original length. Arowanas that don't have it look very odd. For the blue/black and silver arowana, the long appendages on the pelvic fins also don't grow back to the original length. But like someone mentioned above, there could be ways to make them grow back again. When I first bought my blue arowana, it was flawless. However, the blue was very sensitive to my water and the long appendages on the pelvic fins fell off. I was angry, but it was my fault because I didn't acclimate it correctly.