I don't agree at all with Monos and Scats not being kept in captivity. They only get a foot (long or tall depending on the species). There are far worse fish that people keep in captivity like Piranhas, Red Tail Catfish (SA), Shovelnose Cats, Batfish (SW), Golden Trevally's, etc. It is not that hard to duplicate their natural habitat. Sure, they won't get the salinity fluctuations like they do in the wild but they are perfectly happy in captivity. I have 4 Mono Sebaes and 3 Silver Scats among other fish in a 209G Saltwater tank. The Monos are about 4 inches tall and the Scats are about 4 inches long. They are all still babies but see no problem with keeping them in captivity. I think the sad thing is when people keep SA Red tail Catfish in captivity. Unless provided a pool, they are not good captivity inhabitants, not Monos and Scats.