I've started with 27 pictus in a 240 (US) gal 8x2x2ft (then +6 more in a few years). They do fight it out a lot, especially after they sexually mature, and maintain a hierarchy, at times pretty viciously, which is a source of stress, of course, and probably the cause of an occasional premature death.I can not for the life of me keep Pictus in groups for any amount of time, I’ve currently got a single specimen doing great, however the group I had him in just seemed to die off or I would wake up to pieces of them, god only knows but I’m reluctant to try keeping more, which I would love.
I've had problems with tank mate predation and disease - the two primary causes of deaths - and as of now probably down to about 15, that is 5 years later.