schooling / shoaling is interesting... I've been watching a bunch of it lately... for example my Tin Foils, even when they were the biggest fish in the tank, & were 4 inches long, they would gather in a corner & dare each other to go out of the corner... same thing at 6 inches... but now at 6 to 7 inches, they are relaxed they are still crazy at feeding time, but not in a panic... the only change, & in this case what I think made the difference, is I moved my emerging Lucky bamboo to this tank, & it filled a bunch of the open space in the middle, that I had originally left open for swimming space... now they leisurely swim among the bamboo... maybe the open spaces made them nervous???
on my South American tank, the Prestellas ( there are 6 ) 4 of them hang in a loose group, & 2 are almost always out on their own... the Rummy Nose's ( there are 8 ) most always are in a tighter group, they share space with the Pristellas some times
on my African Tetra tank, there are 4 or 5 of each kind... some group with others, but that is in an extra deep tank ( 45 gallon tall ... 3 feet wide, & 2 feet deep ) & they seem to sort out by depth... the interuptus seem to like the top 6 inches, & they share that occasionally with the golds... the balance like the middle of the tank from 6 inches to 18 inches, except the Brichardi, & both the blue & red Brichardi hang out together at the tops of the tangle of Java ferns in the bottom 6 inches... there are about 20 Armano shrimp in the tangle... the fish generally stay out of the plants, except for after all the slowly sinking food has sank, they venture down into the weeds to scavenge food ( it doesn't last very long, with my little king tiger plecos, a couple albino Cory's & all the shrimp on the bottom though
