OK I know this may sound stupid but what does it mean when my silver dollars slap their tails together. and then sometimes one of the tin foils will swim in and try to slap with them.
They are showing aggression to each other. If they dont have enough room, they will fight for dominance by smashing their bodies together, and giving "high fins." What size tank are they in and how big are they?
they are in a 120 gal and are only 3"-4" more than enough room.they show no aggresion that i can see toward anyone but ghostshrimp for food hehehe. also the tin foils try to play with them when they slap. oh ya they like to play follow the leader funny to watch.
Males still fight for dominance any way, so they are probably all males, they are one of the only characins that do that really. Because tinfoil barbs are literally stupid, they dont know that they arent silver dollars, and join in. Ive seen similar cases where bala sharks join in aswell.