Green Neon Tetra

Scientific NameParacheirodon simulans
Common Name(s)Green Neon Tetra, Blue Neon Tetra, False Neon
OriginRio Jafaris; Ornico and Upper Negro River Basins
Temperature Range75-85°F
Water ParameterspH: 5.0-6.5; Hardness: 18-143 ppm (soft water); Freshwater Tank
Adult Size15-25 mm
DietDried food and live food such as bloodworm or mosquito larvae

Green Neon Facts:

1. Despite some sexual dimorphism, both male and female green neon tetra have a bright turquoise stripe that runs along both sides of their bodies.

2. These fish are shoaling fish. This means they have a tendency to gather together. Under safer circumstances, however, this behavior often dissipates and each fish is left to its own devices.

3. Green neon tetra  appear more colorful and splashy when when they are grouped together.


Species Overview:

Green neon tetra (Paracheirodon simulans) are a suitable fish for someone desiring a colorful tropical aquarium. With its flashy appearance and unique behaviors, it is an interesting species to consider buying. However, it is also vital to first consider simulans' very particular needs.

Tropical Habitat

Paracheirodon simulans were first identified in the Rio Jafaris, and are native to the freshwaters of Rio Ornico and the Upper part of the Negro River in South America. Their natural environment allows them to swim in calm waters of tributaries covered in the tree litter of nearby forests.  Suited for a blackwater habitat with high acidity, this fish is typically found among many plants and debris such as: drift wood, hanging branches, and organic decaying material.  It is recommended that one models such an environment when keeping simulans in an aquarium. Therefore, a tank of 10 gallons or more with abundant plant life and sand-like sediment is well-suited for simulans since it supports their natural tendency to hide in shaded areas.  Dim lighting overall is also needed, especially when any eggs are hatching.  Also, no additional ammonia or nitrates should be added to the tank.  An acidic tank environment, with all its plants, soft water, and appropriate temperature range should be established before buying simulans because it is very sensitive to habitat conditions.


Like mentioned previously, this fish is relatively frail because it requires specific water conditions.  Some, but not all, aquarium fish are taken from the wild, so it is not uncommon to see more tentative hiding behaviors than normal in the fish for its first few days of acclimating.  Though simulans can coexist peacefully with other species,  the  habitat conditions it requires makes it not the best fish to put in large communities.  Additionally, due to its petite size, it can sometimes fall prey to larger fish so it is important to keep any predatory species away from green neon tetra.

This recommended  seclusion, however, does not apply when it is among its own species. Typically, green neon tetra can be bought in groups of six or more  because they do normally interact with their peers. This behavior is due to the fact that green neon tetra are a shoaling fish, which , like a schooling fish, means that they have a tendency to group together with their own species, especially in times of danger. One might notice shoaling behaviors such as the fishes swimming along the same vague path.  However,  groups do not exhibit as much coordinated movement as one might expect of schooling fish, which are capable of making intricate swim paths in unison.

The mating of green neon tetra is a fairly regular process and can happen at any time when they are kept in captivity. Females lay over a 100 eggs in shaded areas because UV radiation is harmful at that point in their development. The eggs then hatch in a single day. Parents do not take care of their offspring since the young fish are viable on their own.


Fortunately, feeding the omnivorous simulans is not much trouble. They will eat dried food such as flakes or pellets, which work well since green neon tetra do have tendency to swim closer to the surface of the pond and dry food floats  well.  To supplement their diet, Paracheirodon simulans will also eat  the frozen or live larvae of mosquitoes and chironomia (blood worm).  They will also feed on the small crustacean daphnia. 


Green neon tetra, like other neon tetra, are known for their bright coloration. Their base color is a grayish silver with a long turquoise fluorescent lateral stripe on each side . They have red and green coloration near their head, caudal fin, and ventral region. Their torpedo body shape is similar to neon tetra (Paracheirodon innesi), which are related to green neon tetra. Occasionally, green neon tetra can be marketed for having golden scales;  however, such patterns are actually caused by a parasite, not the fish's natural coloring. Keep this in mind when one sees an advertisement for "gold neon tetra". Interestingly, a green neon tetra 's intensity of coloring is influenced by light conditions as well as being around its own species.

Identifying the  gender of these fish can pose a challenge to some owners since both sexes exhibit elaborate coloration and are, in general, a close match in appearance. However,  when determining sex, the best indicator is the relative sizes of the females and males. Males tend to be slightly smaller than females. Females also have a subtly more bulbous or rounded appearance.

On Name Meaning

The name Paracheirodon simulans can be broken down into several meanings. The prefix "para" means "related to". The genus name of green neon tetra then comes out to "related to cheirodon". Likewise "simulans" , like the word "simular", relates to sameness and means "copying or imitating". Be warned that Paracheirodon simulans  is often mistaken for simply being "neon tetra" rather than "green neon tetra" because of both a similar appearance and name to Paracheirodon innesi. They are different species, and its very easy to mistake articles referring only to neon tetra as something about simulans  when the information is simply not applicable.

Posted on September 15, 2014 and filed under Freshwater Fish.