First let me answer the standard questions
What size is your tank? - 3 Gallon
What temperature is your tank? - 74
Does your tank have a filter? - Yes
Does your tank have an air stone or other type of aeration? No
Is your tank heated? - No
What tank mates does your betta fish live with? Nerite Snail
What type of food do you feed your betta fish? - Pellets and occasional bloodworms (bloodworms are fed about every week or so)
How often do you feed your betta fish? Twice Monday-Friday, none on weekends (it's an office fish)
How often do you perform a water change? - Every 2 weeks
What percentage of the water do you change when you perform a water change? - 30% per the tank's guidelines
What type of additives do you add to the water when you perform a water change? - Tetra Betta Safe Water Conditions
Have you tested your water? If so, what are the following parameters?
Had water tested at local aquarium store today. All levels below were fine
Symptoms and Treatment
How has your betta fish's appearance changed? - He looks the same, color is fine, eyes look fine. He does not appear bloated
How has your betta fish's behavior changed? - Lethargic, won't swim around and won't eat, just hangs out in the top back corner of his tank (his favorite place)
When did you start noticing the symptoms? - 4 days ago
Have you started treating your fish? If so, how? - See Below
Does your fish have any history of being ill? - No
How old is your fish (approximately)? - 18 Months
So I have had my betta for approximately a year and the pet shop said he was about 9 months old when I brought him home. I have changed nothing in his tank, he's getting the same food he always does and same feeding I've been doing since I've had him. 4 days ago he started lunging at the food like he wanted to eat it but he would either miss the food or he would get it in his mouth but he spit it back out. I assumed he was just "playing" and figured he would eat when he got hungry. The next day he was lethargic, in his favorite spot which is the top corner next to the motor for the filter. He refused to move. I left for the weekend and now today he's still acting the same. He looks almost comatose and I would think he's dead except occasionally his little flipper fins will move. He did make one lap across the tank but he was very slow and it looked like it took all he had to make that lap. He did swim upright, not leaning to one side.
I went to the local aquarium store and they tested my water and said all levels were fine. They thought maybe his tank was too cold and he might be in shock. I don't think this is it, he lived through the winter and I know my office building was colder then. They also suggested that he might be "bored" with his food and gave me live blood worms. I put them in the tank and this did nothing for him. He still won't move. I asked what I should do if the worms don't improve him and they said there wasn't much else and that maybe it's just "his time". This makes me so sad as I'm not sure why he would be ready to go so soon. Any ideas on what could be wrong?