Do Your Shoaling Fish Shoal When The Lights Go Out?

[Maroonostrich]

Hi

My light is not working at the moment but when it was, I would always notice how the neons would rush together when I put the tank light on. I always put the light off before I put the room lights off and still they would gather extremely quickly when the light went out! It was quite impressive.. they seemed to relax after a bit and slowly scatter again. Do all shoaling fish react this way?

 

[Ben]

yes.
Schooling/shoaling is a defence reaction.
Very few fish only school for company(cories, for example, do).
Tetras and other Characins and Cyprinids school tightly when they get startled (such as the light coming on) or if theres a predetor or if they're scared. If theres nothing to worry about, they usually scatter and swim about but alwyas stay close.

This is why it is ALWAYS recomended you buy these types of fish with 5 or more (three the minimum), so they feel safe in your aquarium and act naturally.

HTH

DD