Here's what you need to do:
1. Contact a qualified veterinarian specializing in aquatic animals immediately. They can diagnose the problem and recommend the appropriate treatment.
2. While waiting for professional help, observe your puffer fish closely. Note any other symptoms, such as changes in appetite, color, or behavior. This information will be helpful to the vet.
Possible reasons for your puffer fish floating:
* Swim bladder issues: This is a common problem in fish, and it can be caused by various factors, including infections, parasites, and dietary deficiencies.
* Water quality issues: Poor water conditions, such as high ammonia or nitrite levels, can affect a fish's buoyancy.
* Internal parasites: These can cause bloating and make it difficult for your puffer fish to swim.
* Constipation: This can also lead to bloating and floating.
* Overfeeding: Feeding too much can cause digestive issues, including floating.
Important Note: It's crucial to seek professional help. Attempting to treat your fish yourself without a proper diagnosis can be harmful and potentially fatal.