Thank you for your advice!
He lives with his brother in a 45 gallon divided tank, he and his brother on one side, 2 sisters on the other, so he only shares his food with his brother. He has always been super thin since hatch, his albino siblings are all hefty. I feed once/day, in the morning, one cube of bloodworms, mysis shrimp, brine shrimp or krill, divided among the 4. The food goes onto a serving dish and both boys go at it. I have never witnessed any bullying or aggression and he seems to eat as much as his heftier brother so I assumed he was just skinnier by nature, since he has always been skinny. Do you feel I need to increase the amount of food?
My boy is alive and more active this morning, having spent the night in separate housing. I had fed him 4 bloodworms last night and just now, he ate 8 more in succession. I am headed to aquarium shop this morning, I will ask for blackworms. What else can I rotate into their diet?
If I do put him in the fridge, for how long? The entire weekend? He is in a room with a/c now and is more active this morning, than he was last night.
Thank you for this help.