i know...i know....before you make fun of my ignorance......please allow me to explain......they usually get 15" in the wild...or even more than 25" for some species like D. hystrix......but under normal captive conditions (i.e. not much room to swim around and overstocking), they do not get as big as they're supposed to be.......i've seen many gargantuan porkies in huge aquariums......including puiblic ones.......but the biggest one kept by ordinary aquarists that I've ever seen so far was around 6-7". This is why one's tank should be as large as possible to promote their optimal growth. but, unfortunately, this is not the case........for most people....just wanted to clarify my point!