Looks like a prison yard where the inmates are slowing swirling round trying to look innocuous and hoping not to be in the wrong section of the tank when the inevitable fight breaks out.
It's unlikely there is any "natural" place where the mixed species fish density is that high.
Wow, that must take some fancy science to pin the date down so precisely.
//I'm making a homage of crushed diet coke cans that makes a shadow spelling out DUPLICATE.
It's unlikely there is any "natural" place where the mixed species fish density is that high.