4 replies to this topic

[centrarchid]

I have a 300-gallon tank by barn with some longear and bluegill in it.  Tank is about 36" deep.  Each night the sunfish come up to sleep on ledge just below surface.  During the day they are not to be seen.  Will be watching for roosting site fidelity.  Individuals can be discerned by patterns and size.

[gerald]

Maybe related to dissolved oxygen stratification?  Hard to get a good nights sleep if you can't breathe.

[Michael Wolfe]

maybe predator avoidance specific location?  would they fear herons more in the day... most wading predators seem to actively "look into the water".  on the other hand, large catfish prowl around at night, so shallow water helps you avoid bigger fish?  At least that's my hypothesis,

[NotCousteau]

I definitely have some fish that roost higher in the aquarium at night. Maybe its just a species thing?

Cool observations. Thanks for sharing, and keep us updated. Photos would be cool.

[Matt DeLaVega]

maybe predator avoidance specific location?  would they fear herons more in the day... most wading predators seem to actively "look into the water".  on the other hand, large catfish prowl around at night, so shallow water helps you avoid bigger fish?  At least that's my hypothesis,

This is pretty much what I think. I have a hypothesis too, but it would take a while and pretty much leads to what Michael said. It makes sense to me.