Hi,
I have a cory catfish in a ten gallon tank all by himself. I am not sure what species he is, but he has black speckles along the back. Anyhow, he just sits at the bottom of the tank and barely moves. I hear they are nocturnal, but even at night I see him doing nothing. Sometimes I will nudge him and he will just sit there (no he is not dead because I still see him feeding on occasion or he will cycle between sitting in two or three different spots in the aquarium). Also, I feed him sinking wafers but he doesn't eat them. I dunno what to do....I hope he is ok.