Banjo cats are perfect omnivores and will eat anything they can fit into their mouths, and will also chew on large sinking pellets and algae wafers. Different species of banjo attain differing max lengths, but the common species grow to between 4" and 6" on average. I have what I believe to be one bunocephalus amazonicus and one bunocephalus coracoideus. I've owned them both for only a few months. The amazonicus is almost 5" and still growing, the coracoideus seems to be a slower grower and is now 3".