The type species of its genus, it is native to blackwater and clearwater streams in the Amazon basin of South America.

[4] UN FAO considers P. innesi an introduced species in Singapore[7] and the United States.

The fish is characterized by an iridescent blue horizontal stripe along each side of the fish from its nose to the base of the adipose fin, and an iridescent red stripe that begins at the middle of the body and extends posteriorly to the base of the caudal fin.

[10] The neon tetra was first imported from South America and was described by renowned ichthyologist George S. Myers in 1936, and named after William T.

[12] Most neon tetras available in the United States are imported from Southeast Asia, where they are farm-raised, or to a lesser extent from Colombia, Peru, and Brazil, where they are collected from the wild.

[13] During a single month, an average of 1.8 million neon tetras with an estimated value of $175,000 are imported into the United States for the aquarium trade.

[19] Neon tetras are considered easy to keep in an aquarium of at least 10 US gallons (38 L; 8.3 imp gal) with a temperature range of between 72–76 °F (22–24 °C), a water pH of between 6.0 and 7.0, GH of below 10 dGH and KH of 1–2 dKH, and under 20 ppm of nitrate.

[21] Neon tetras are best kept in a densely planted tank to resemble their native Amazon environments.

However, the straightness of the line and the plumpness of the female might occasionally be due to the eggs she is carrying.

[26] The disease cycle begins when microsporidian parasite spores enter the fish after it consumes infected material, such as the bodies of a dead fish, or live food such as tubifex, which may serve as intermediate hosts.

Symptoms include restlessness, loss of coloration, lumps on the body as cysts develop, difficulty swimming, curved spines as the disease progresses, and secondary infections, such as fin rot and bloating.