[Chasmodes]

Ah man, sorry to hear that (condolences). I lost a goby and a skilletfish over the last month, both seemed healthy, parameters OK, no signs of disease in the tank. It happens. I suspect that perhaps some sort of internal problem that we can't see sometimes cause them to die earlier, parasite or disease. Or, old age maybe. How long do barnacle blennies live?

I like McPuff's suggestion about gut loading meds in the food, in case there are internal parasites. I am going to try that.