I have heard that they can live around 20 years in captivity and sometimes longer! A good guess is that the average lifespan is around 15 years. I had a frog that was 9 years old, she passed away to an unknown illness. If well cared for these frogs will be a long lived companion.
It takes them about 7-12 month to reach full size from froglet stage. Water quality, correct diet and tank size encourages proper growth. Poor diet, too small a tank and/or overcrowding and unclean water can cause stunting in their growth and other problems such as bone deformities, illness and even death.