Clade Common Names:
False Neon Tetra, Green Neon Tetra Origin and Habitat:
Middle Rio Negro basin; found by Heiko Bleher as far north as the Vichada in Columbia. Compatibility/Temperament:
Very peaceful and quiet, suitable for an aquarium of similar soft and acidic water fish. Must be kept in a group, minimum six but preferably more. The fish generally remain together in a shoal. Individual fish sometimes appear in shipments of the cardinal, P. axelrodi
, as the two species occur together in certain habitats. Green Neon Tetra Diet
Carnivorous; will accept most commercially produced foods. Size
Maximum length 1.5 inches but usually much smaller, around 1 inch. Minimum Tank Suggestion
24 inches in length Water parameters for Green Neon Tetra
Soft (less than 4 dGH) and acidic (pH 6.0 or below) water essential for long-term health, temperature 23-27C/73-81F. This species is sometimes found in the same waters as the cardinal tetra (termed sympatric) and both fish share identical water parameter requirements. Description
Similar in appearance to but smaller than the Cardinal Tetra; the red below the "neon" lateral line is less brilliant. The neon line extends from the eye to the caudal peduncle (base of the caudal fin) and is thus the longest and straightest of the four "neon" species. This gives this fish a more slender, straight appearance.
To date, all fish commercially available are captured in the wild. This species shares identical habitat and water parameter requirements with the Cardinal Tetra, and the two species are sympatric over portions of their range. The species was discovered in 1962 from individuals that were mixed in with cardinal tetras. The pH of the habitat waters ranges from 3.4 to 4.8, with hardness so low it can hardly be measured. Neither fish fares well in tanks with hard and basic (alkaline) water. To replicate their habitat, the aquarium should have a sand or fine gravel substrate, and plenty of aquatic plants like Echinodorus
, Pennywort, and floating plants. Water flow from the filter should be minimal, with subdued lighting. This species prefers the middle regions in the aquarium, unlike its cousin the Cardinal Tetra which prefers the lower regions.
The iridescent blue/green line contains pigment cells known as iridophores (or sometimes guanophores); these reflect light using plates of crystalline chemochromes made from guanine. In light, these generate iridescent colours due to the diffraction of light within the stacked plates.
Sexual dimorphism, like most other tetras, can be difficult to determine but males are often smaller and always slimmer in comparison with the females when viewed from above. Spawning is not easy to achieve. They are egg scatterers and require very soft and acidic water and darkness.
This fish is often commonly called the false neon tetra. The original description by Gery (1963) placed it in the genus Hyphessobrycon
as H. simulans;
the species epithet simulans is Latin for "similar" and references the colour pattern similarity to the neon tetra. Fink & Weitzman (1977) placed it in the genus Paracheirodon
[see below] with the two other neons, and subsequent DNA results have confirmed this placement. The Cardinal Tetra and the Green/False Neon have 26 and 25 chromosomes respectively, while the common neon tetra has 16.
In 1960, Dr. Jacques Gery erected the genus Paracheirodon
for the type species P. innesi
(Neon Tetra) and Gery also moved the Cardinal Tetra into the new genus. The name Paracheirodon
derives from the Greek; the older genus name Cheirodon
derives from cheir
[= hand] and odon
[= teeth], and the prefix para
means "beside" to distinguish Paracheirodon
was formerly considered within the subfamily Tetragonopterinae, but this classification has for some time been deemed incertae sedis
[Latin for "of uncertain placement"]. Javonillo, et al. (2010) determined that the subfamily Tetragonopterinae should only be used for species within the genus Tetragonopterus
. Also, J. Marcos Mirande (2009) proposed several revisions to the family Characidae based upon phylogenetic diagnosis. Some genera have been moved to a new subfamily, while others are now (temporarily) assigned to a specific clade within the family pending further study.
The presence of the "neon" blue/green lateral stripe readily identifies the neon tetra [P. innesi
], cardinal tetra [P. axelrodi
] and false or green neon tetra [P. simulans
], all of which are available in the hobby. A fourth "neon" species was discovered by Heiko Bleher in 2006 and has yet to be described and named. According to preliminary DNA studies, this new species is very close to the true Neon Tetra, whereas the Cardinal Tetra is genetically closer to the Green/False Neon Tetra. References:
Javonillo, Robert, Luiz R. Malabarba, Stanley H. Weitzman and John R. Burns (2010), "Relationships among major lineages of characid fishes (Teleostei: Ostariophysi: Characiformes), based on molecular sequence data," Molecular Phylogenetics and Evolution
, Vol. 54, No. 2 (February 2010).
Mirande, J. Marcos (2009), "Weighted parsimony phylogeny of the family Characidae (Teleostei: Characiformes)," Cladistics
, Vol. 25, No. 6 (July 2009). Contributing Members
The following members have contributed to this profile: Byron