They are fairly small (around 4-6") and not real active so one can be kept in smaller containers like a 5G globe or jar, they like large leaf plants like cryptos and often sort of hang in the water in the shelter of the leves. Then when you drop in a molly or shrimp they will slowlt drift that way the suddenly suck in the prey. Pretty cool mini-monster for a desktop. They are one of the few medium sized fish I would crowd like that. They do well in neutral ph water, around 8 Dh, and low 80s F. I used to have a huge brandy snifter (about 5g) that contained a ugf and a potted cryptocorme and some elodea, with a pair of C. oxyrhychum in it that was given to me, no problems, The desk lamp kept it at about 80 degrees.