Neon tetra disease (NTD) is a microsporidian parasite that infects neon tetras, cardinal tetras, and many other small tetras. There is no effective treatment - infected fish should be euthanized to prevent spread. Affects 50-90% of imported neons in some shipments. Symptoms to look for.
1. Neon Tetra Disease (NTD). Cause: A parasitic infection caused by Pleistophora hyphessobryconis. Symptoms: Faded or pale coloration. Difficulty swimming or erratic movements.
5 HIDDEN Symptoms of Neon Tetra Disease in Aquarium Fish (CANT Ignore). Neon fish Disease is notorious for its subtle early signs, often making diagnosis difficult until the disease has progressed significantly.

The neon tetra is one of the most iconic and beloved freshwater aquarium fish, instantly recognizable by its iridescent blue-green back and brilliant red stripe running from midbody to tail.
9 months old in community tank 1 of 11only one that has this symptome [ATTACH].It could be a number of diseases, such as neon tetra disease, internal parasites, mycobacteriosis, are just some that I know of that may cause bloating either as a primary or secondary symptom.

Neon Tetra Aquarium Fish in planted TankMinimum Tank Size: 5 Gallons (10 Recommended)Care Level: EasyWater Conditions: PH 5.5-7.5 and Soft to MediumTemperatu...
11. Fish Disease Symptoms. One caution about diagnosing fish diseases. Even with a microscopic examination fish diseases are not easy to diagnose.11.11. Red Skin Blotches. 11.12. Neon Tetra Disease.