I have a dozen young S. petricola in my 55, along with 7 of the C*fish from the same neighborhood. I was told it would take several years for the cats to reach breeding size, but I am seeing them grow faster than anything else in the tank. In a couple months, they have just about doubled in length from the 1-1.25" fry they started as, some of them larger than others.

Is there any significant difference in length of mature males and females, or is it just the stronger, healthier fish growing faster?
At what size do they become sexually mature, and how do you tell the males and females apart?