The green neon tetra (Paracheirodon simulans) is a freshwater fish of the family Characidae of order Characiformes. It is native to the upper Orinoco and Negro Rivers in South America.
This fish is similar in appearance to the closely related and better-known neon tetra, but it is slightly smaller, and its red patch is less pronounced, while the blue-green areas of the upper body are more brilliant. Also, its body is slimmer than that of the neon tetra. It grows to a maximum overall length of about 3.5 cm (1.4 in).
Like the other Paracheirodon species, the green neon tetra is kept as an aquarium fish, but it is less commonly seen than either the neon tetra or the cardinal tetra.
P. simulans is also sometimes called the blue or false neon. Hyphessobrycon simulans and Cheirodon simulans are obsolete synonyms.
A Green neon tetra with the lack of red stripe clearly visible
This fish loses its brilliant blue and red colors when lights are switched off, but regains them when lights are switched on again. The green neon tetra comes from extremely soft, acidic water at temperatures around 24 to 29 °C (75 to 84 °F).
Source: Wikipedia contributors. Green neon tetra. Wikipedia, The Free Encyclopedia. August 1, 2019, 17:27 UTC. Available at: https://en.wikipedia.org/w/index.php?title=Green_neon_tetra&oldid=908887477. Accessed October 18, 2019.