Originally Posted by Betsy
If the open brain doesn't have it's tentacles out does that mean it's not hungry? Do you try to feed it even then and how?
As Innovator stated, the tentacles extend when food is sensed or at night (almost like clock-work, mine extend their feeder tentacles within 10min of the lights going out). I feed mine exclusively after dark. I've even seen them capture small tiny nocturnal shrimp in my tank which were attracted to the beam of the flashlight.
From my observation, while they can get by and thrive on light alone, they seem to put regular effort into prey capture (extending feeder tentacles nightly) perhaps as a survival mechanism to counteract the effects of overcast or cloudy days in the wild and avoiding a nutrient deficit?