I love irridescent sharks! Never had any though.
As you probably know, they are a species of catfish. They are usually sold young at around 3 or 4 inches. They have long barbles, and are a dark blackish/silver color with much sheen.
They get quite large as bunjiweb mentioned, and they lose their sheen as they mature, becoming a plain greyish color.
Not really a fish to keep unless you have a gigantic tank or pond. They will eat pretty much anything, especially smaller fish (they are not a suckermouth species). The males sometimes have stripes and are more sleek than females.
Younger ones are more carnivorous than adults, and should not be fed a large amount of feeder fish at any stage in its life. If kept with the right fish, it can be rather peaceful.
That's not a fish that many people (if any) here can keep.
They look cute as juveniles, with the aforementioned sheen. However, they quickly lose that sheen and grow really big or die because they're cramped into small tanks.
i have 2 baby ones, there really cute little fishesw, theyre in a smaller tank now because theyre small, but im going 2 put them in larger ones as i get older.