I have 4 corydoras - 2 pairs, 2 peppered and 2 albino in an 180 liters tank, together with 2 ancistrus, 5 SAE, 10 werners, one otto and about 20 neeons. I have had the corries since they were young, 3-4 years ago. 4 days ago I found one of the peppered ones (the female) laying on the bottom belly up...