I got a fire fish this past week. Delivered by UPS on Wednesday. It was delivered late, and left outside on my porch for two hours because they didn't knock or let me know it was there. I brought it in and got it acclimated, and as expected, it zipped off and hid when I released it in the tank. It came out later that evening and seemed fine before lights out. I haven't seen any sign of it since then. Is that normal, or should I be looking for a dead fish?