Description
The green neon tetra, Paracheirodon simulans, is the discreet relative of the neon: a 2.5 cm characid from the Negro and Orinoco rivers, in Brazil, Colombia and Venezuela, told apart by a greener lateral stripe that reaches the base of the tail and flanks of a duller red than the common neon and the cardinal. It is also sold as the false neon or blue neon.
It is an exclusive inhabitant of blackwater, in the upper reaches of tributaries, and that explains its pH range, among the most acidic in the catalogue. Every fish in the shops is wild-caught and arrives delicate, so it needs care in the period after import.
Behavior
Peaceful with other species, but not an ideal community fish given its size and requirements. The ideal is a tank of its own, or with diminutive, non-aggressive characids and small callichthyid or loricariid catfish. It is gregarious and forms schools: eight to ten is the minimum, because with fewer it is shy and less interesting.
It lives well with other diminutive characids, dwarf corydoras and small loricariids.
Avoid housing it with larger or lively fish, which intimidate it and take its food.
Habitat
Paracheirodon simulans lives in the middle and upper Negro basin and in the Orinoco system, on the border between Venezuela and Colombia. It occupies only blackwater in the upper reaches of tributaries, with slow to moderate flow, thick and often overhanging riparian vegetation and sandy bottoms with branches, roots and leaf litter. The water is acidic, with almost no hardness or conductivity, and stained brown.
Neón verde is a schooling species, which means that in the wild it lives and moves in large, coordinated groups.
Keep at least 8 individuals so they feel comfortable and their stress level stays low.
Details
🌊 Water parameters
🐠 Minimum tank size
Breeding
It is not commercially farmed, which is why it is less common and dearer than its relatives. It spawns better in a school than in a pair. Some wild specimens have golden metallic scales, thought to be caused by a parasite, and are sold as «platinum» or «gold».
Diet
A probable omnivore: in nature it would eat small invertebrates, crustaceans, filamentous algae and fallen fruit.
- Staple: small flakes and granules.
- Supplement: bloodworm and mosquito larvae, daphnia or moina, live or frozen, for a varied diet.
What about your tank?
Enter your tank's values to see only the compatible species that fit them. Litres apply to fish.
Compatible fish
General guidance based on water parameters, behaviour and known exceptions; always review the individual animals' and aquarium's specific needs.
They share water: pH 6–6.5 and 24–27 °C.
They share water: pH 6–6.5 and 23–27 °C.
They share water: pH 6–6.5 and 23–27 °C.
They share water: pH 6–6.5 and 23–27 °C.
They share water: pH 6–6.5 and 24–27 °C.
They share water: pH 5.5–6.5 and 24–27 °C.
They share water: pH 6–6.5 and 23–26 °C.
They share water: pH 5.5–6.5 and 23–27 °C.
They share water: pH 6–6.5 and 25–27 °C.
They share water: pH 6–6.5 and 24–27 °C.
They share water: pH 6.5 and 24–26 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6–6.5 and 23–26 °C.
They share water: pH 6–6.5 and 23–25 °C.
They share water: pH 6–6.5 and 24–27 °C.
They share water: pH 6.5 and 23–24 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 5–6.5 and 27 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6.5 and 23–27 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6–6.5 and 25–27 °C.
They share water: pH 6–6.5 and 23–27 °C.
They share water: pH 6–6.5 and 23–27 °C.
They share water: pH 6–6.5 and 24–27 °C.
They share water: pH 6–6.5 and 24–27 °C.
They share water: pH 5.5–6.5 and 24–27 °C.
They share water: pH 5.5–6.5 and 23–26 °C.
They share water: pH 6.5 and 23–26 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6–6.5 and 23–26 °C.
They share water: pH 6.5 and 23–24 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 4.5–6.5 and 23–27 °C.
They share water: pH 4–6.5 and 23–27 °C.
They share water: pH 5–6.5 and 23–27 °C.
They share water: pH 4–6.5 and 23–27 °C.
They share water: pH 5.5–6.5 and 26–27 °C.
They share water: pH 5.5–6.5 and 23–26 °C.
They share water: pH 6.5 and 23–26 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 4.5–6.5 and 24–27 °C.
They share water: pH 5.5–6.5 and 23–27 °C.
They share water: pH 5–6.5 and 23–27 °C.
They share water: pH 5.5–6.5 and 23–27 °C.
They share water: pH 5.5–6.5 and 24–27 °C.
They share water: pH 6–6.5 and 23–26 °C.
They share water: pH 5.5–6.5 and 23–27 °C.
They share water: pH 5.5–6.5 and 23–27 °C.
Compatible invertebrates
General guidance based on water parameters, behaviour and known exceptions; always review the individual animals' and aquarium's specific needs.
They share water: pH 5.5–6.5 and 23–24 °C.
They share water: pH 6.5 and 23–27 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6.5 and 23–26 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 5.8–6.5 and 23–24 °C.
They share water: pH 5.8–6.5 and 23–24 °C.
They share water: pH 6.5 and 23–27 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6.5 and 23–26 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6.5 and 23–26 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6.5 and 23–26 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6.5 and 23–26 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6.5 and 23–26 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6.5 and 23–26 °C. They only meet at the very edge, so the tank has to hold that value.
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They share water: pH 6.5 and 23–27 °C. They only meet at the very edge, so the tank has to hold that value.
Sources
- FishBaseFroese, R. and D. Pauly. Editors. 2026. FishBase. World Wide Web electronic publication.
- Seriously FishSeriously Fish. Paracheirodon simulans. Ficha de especie; consultada 2026-10.
Water: FishBase gives pH 5.5-6, hardness up to 4 dH (no minimum) and 23-27 °C; Seriously Fish, pH 3-6.5, 1-8 dGH and 24-27 °C. The profile uses the widest range, temperature (23-27) and hardness (1-8) included. Seriously Fish adds that water in its natural habitat has been recorded at 24.6 to 35.2 °C, and that the species may have evolved a tolerance to heat; that figure is not part of the profile's range. Size: 2 cm SL in FishBase and 2.5 cm SL in Seriously Fish; the larger is taken.
Litres per fish and minimum tank height and depth: the profile's own judgement. Seriously Fish gives only the tank base and FishBase gives no tank sizes.
Plan your next aquarium
Is this fish right for you? Plan a suitable aquarium before setting it up.