gouramis are very sensitive to overcrowding. all species of them can get aggressive if they're feeling cramped.
but what you're seeing is a pretty typical pecking order. usually there's one or two that loo nearly flawless, going down to the one that looks pretty rough. with 11 of them, you should be ok.
but what you're seeing is a pretty typical pecking order. usually there's one or two that loo nearly flawless, going down to the one that looks pretty rough. with 11 of them, you should be ok.