In a school of rummy-nose tetras, a common aquarium fish, group coordination appears to occur by each fish continuously changing which of its neighbors it pays attention to, according to new ...

Add a school of Rummy Nose Tetras though and you'll not have any complaints from the rest of your fishy community. Otocinclus Catfish are small algae eaters that thrive in groups.

The rummy-nose tetra species appears to have chosen this co-ordination strategy where any individual may become a leader depending on the need.