I just raised up a redfinned kandango and a (female) venustus also . I found mine grew at the exact same pace. I got them the same week and they were in the same tank (135 long), they are both fairly fast growers. I have another male venustus that was 4 -5 inches and has grown to 6-7 inches but does not seem to have put on alot weight compared to the female and the borleyi. The female and borleyi are growing so fast they are quickly catching up to the larger grown male that i bought. So i figure they reach a plateu when growing and slow down once they reach 5 -6 inches or so , still growing just at a much slower rate maybe ?