Glass cats, K. Minor. (Bicirrhis) I have kept mine for at least 5 years. Never fed them live food. They have been kept with all species that I have kept except the puffer. I have kept many fish over the years.
I feed mine frozen black mosquito larvae exclusively. They will eat other food but not in the same way. They, by my experience only eat after lights out, either end of the day. Any time the lights are on they won't feed at all.
My advice to you, when you buy new fish, isolate the species, this way you can check not only for ill health but also when it eats and what it eats. When I started out I had frozen multi blisters with a few different types in and a range of dried foods, each day the fish were tried on a different type of food, at both times lights on/off. Notes were made on preference to food and light mode and time of day.
Some fish just eat, others are more specific.
The glass cats will tolerate pretty much any water condition pH 6.7/7.6 will present no problems, well filtered is a must. If kept with tetra, feed tetra first at lights on, feed cats lights off. Trust me they will fight for the food, they really come alive at feeding time, that's the reason I still keep them, to watch them eat.
I don't mention nitrogenous waste levels because these should always be kept to a minimum.
It probably wasn't the shop, both batches I bought lived for a considerable time.
Did you ever observe the fish feeding?
