Baby Paretroplus menarambo Doing the 'Shake'.
I've been raising a batch of 'menarambo' (~ 150) in a 25G , bare bottomed tank for the last month. A few days ago, I decided to split the fry up, whereupon I moved about half of them to another 25G, this time with silica sand substrate. As expected, these fry, when cleaning up food particles from the bottom do a head shaking movement to kick up the food morsels. It's comical to see these little 1" babies doing what their parents do. Here's a video of some little ones doin' the shake.
"The only reason for time is so that everything doesn't happen at once"