Hyphessobrycon herbertaxelrodi
Despite the name, not closely related to the common neon, different genus, different river basin. White-and-black horizontal striping with a greenish iridescence. Hardier and more tolerant than the standard neon, ideal for community tanks with stable parameters.
Black Neon Tetra (Hyphessobrycon herbertaxelrodi) reaches 3–4 cm as an adult and needs a minimum tank of 60 L. Native to Paraguay River basin, Brazil, it lives in the mid water column with a peaceful temperament. Aim for 22–28 °C, pH 5.5–7.5, and 2–12 dGH hardness. Lifespan is 5 years with good care. Keep black neon tetra in groups of 8+, yes schoolers need numbers to display natural behaviour. Diet: omnivore, Crushed flake, micro pellets, frozen daphnia, baby brine shrimp. Plant-safe: Yes. Shrimp-safe: Mostly (may eat shrimplets).
Care at a glance
Despite the name, not closely related to the common neon, different genus, different river basin. White-and-black horizontal striping with a greenish iridescence. Hardier and more tolerant than the standard neon, ideal for community tanks with stable parameters.
By Mike ElmiraUpdated 2 min read
Part of our complete guide to aquarium fish for the planted tank.
The parameters that decide whether black neon tetra fits in your tank.
Mid
Yes
Group of 8+
Characidae
Omnivore
Crushed flake, micro pellets, frozen daphnia, baby brine shrimp.
5 yrs
Medium
Slow soft-water streams of the Paraguay basin
Paraguay River basin, Brazil
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Any peaceful South American community: cardinals, neons, rummynose, corydoras, otocinclus, rams.
Fin-nippers, aggressive cichlids, anything large and predatory.
Hard-won lessons from the tank.
Pair with common neons or cardinals in the same tank for a stunning contrast — the dark horizontal stripe of the black neon mirrors the bright neon stripe of its lookalikes. A shoal of 12+ in a 75 L planted blackwater tank looks excellent. More forgiving than common neons for community-tank conditions.
Genus 'Hyphessobrycon' = 'small Brycon' (related characid genus). Species 'herbertaxelrodi' honours Herbert R. Axelrod, American ichthyologist.
What can go wrong and how to spot it.
Failure modes, in order of how dramatic the fix is.
More robust than the common neon — significantly less susceptible to Neon Tetra Disease. Standard tetra care.
Not actually a 'neon' — different genus from Paracheirodon (the true neons). The 'black neon' label is purely a marketing similarity based on the horizontal stripe.
The practical routine, read top to bottom.
60 L+. Heavy planting with open mid-water swimming. Dark substrate, dim lighting, tannins for best colour. Sponge or low-flow canister filter.
2–3 weeks. Settle quickly.
Where it comes from, how it behaves, and the variants you'll see at retail.
Where it lived before it came home.
Paraguay River basin and its tributaries. Tannin-stained slow-moving water with dense vegetation, leaf litter, and submerged roots.
Insect larvae, micro-crustaceans, biofilm, fallen invertebrates.
Not threatened. Captive-bred globally.
How they pair, reproduce, and grow.
Females slightly rounder when conditioned. Males marginally slimmer with brighter colour. Difficult outside breeding condition.
Egg scatterers. Soft slightly acidic water at 26 °C, dense moss or spawning mop. Adults eat eggs — remove after spawning. Fry need infusoria first week, then baby brine shrimp.
The named cultivars and the lookalikes worth flagging.
Wild type. Occasional 'long-fin' and 'albino' variants.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Black Neon Tetra (Hyphessobrycon herbertaxelrodi) needs a minimum tank of 60 L. They live in the mid water column and should be kept in groups of 8+, so a longer footprint matters more than depth.
Target 22–28 °C, pH 5.5–7.5, and 2–12 dGH hardness. Acclimate slowly when moving them between water sources.
Shrimp safety: Mostly (may eat shrimplets). Plant safety: Yes.
Black Neon Tetra are omnivore. Crushed flake, micro pellets, frozen daphnia, baby brine shrimp.
On Fin & Stem's 1–5 difficulty scale this species rates 1/5. Almost unkillable, a solid first-tank choice. Breeding difficulty: medium.
Typical lifespan in a well-maintained tank is 5 years.
A planted tank is a system. Pair this fish with one entry from each other pillar to plan the whole scape.
