Last weekend I had a slight tank emergency as in my tank stand broke taking my tank along with it. Luckily I had a couple other tanks already setup so I was able to salvage the majority of fish. I acquired a new tank and decided I was going to put my julii cories in there since I had the chance to make a sand substrate and I thought they would appreciate that.
So in go 12 cories and a juvenile male betta. After a couple days of monitoring I realize that the cories just aren't as active as they usually are. I figured it was because they got moved twice in a couple of days or maybe they needed more floating plants to block the light. They were given plenty of cover (tank is heavily, heavily planted) so I don't think that was the case.
I remembered reading how some fish like to have 'dither' fish swimming around so they know it is safe. I needed to get some type of schooling fish anyways for the tank to finish it off so I ran to the store and scooped up 10 Harlequin Rasboras.
After introducing them to the tank and having the betta chase them around for a bit things settled down and I waited for the next day to see if there was any change in the cories.
Well it is the next day and I'm happy to say that the cories are back to their old selves again swimming around the whole tank and acting like children. It could be that they finally got used to the tank, but I like to attribute it to the fact they see 10 happy Harlequins swimming around and they feel safer because of it.
I don't like adding this many fish at once to a new tank, but its heavily, heavily planted, established media from my other tanks is in there, I watch water parameters like a hawk and have been doing frequent water changes until things get established. For now everyone seems happy and the betta is used to his new roommates.
I'm glad to see that dither fish have a more important role to play than my own amusement of watching them swim around together.