Moenkhausia pittieri
Iridescent silver-gold scales catch every angle of light. Plain juveniles transform into sparkling adults over 6–9 months. Males develop extended dorsal and anal rays. A planted-tank classic in the AGA showroom tradition.
Diamond Tetra (Moenkhausia pittieri) reaches 5–6 cm as an adult and needs a minimum tank of 100 L. Native to Lake Valencia basin, Venezuela, it lives in the mid water column with a peaceful temperament. Aim for 24–28 °C, pH 6.0–7.5, and 4–15 dGH hardness. Lifespan is 4–6 years with good care. Keep diamond tetra in groups of 6+, yes schoolers need numbers to display natural behaviour. Diet: omnivore, Flake, micro pellets, frozen daphnia, bloodworms, occasional plant matter. Plant-safe: Yes. Shrimp-safe: Mostly (may eat shrimplets).
Care at a glance
Iridescent silver-gold scales catch every angle of light. Plain juveniles transform into sparkling adults over 6–9 months. Males develop extended dorsal and anal rays. A planted-tank classic in the AGA showroom tradition.
By Mike ElmiraUpdated 2 min read
Part of our complete guide to aquarium fish for the planted tank.
The parameters that decide whether diamond tetra fits in your tank.
Mid
Yes
Group of 6+
Characidae
Omnivore
Flake, micro pellets, frozen daphnia, bloodworms, occasional plant matter.
4–6 yrs
Medium
Vegetated shore margins of Lake Valencia, Venezuela
Lake Valencia basin, Venezuela
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Most peaceful South American community fish: cardinal tetras, rummynose tetras, corydoras, dwarf cichlids (apistogramma, ram). They're large enough not to be eaten by most predators.
Fin-nippers (tiger barbs, serpae tetras), aggressive cichlids. Avoid mixing with smaller more delicate fish — diamonds out-compete at feeding.
Hard-won lessons from the tank.
Display group of 8+ in a long planted tank with dim warm lighting. The iridescence shifts colour based on viewing angle — silver, gold, blue, green flashes as they turn. Pair with a school of dark-coloured fish (like rummynose) for visual contrast. Buy from a single source to ensure consistent genetics and maximize finnage development.
Genus 'Moenkhausia' honours German-American ichthyologist William J. Moenkhaus. Species 'pittieri' honours Swiss-born botanist Henri Pittier who explored Venezuela.
What can go wrong and how to spot it.
Failure modes, in order of how dramatic the fix is.
Robust. Watch for fin damage if kept with fin-nippers — those flowing fins are tempting targets.
Juvenile diamonds look plain and uninteresting — the iridescence develops over months. Many shoppers walk past them. Buy a group of young diamonds and watch them transform.
The practical routine, read top to bottom.
100 L+ for a meaningful group. Open swimming space with planted edges. Dim warm lighting brings out the iridescence; bright cool lighting washes them out. Sand or fine gravel.
3 weeks. Standard tetra care.
Where it comes from, how it behaves, and the variants you'll see at retail.
Where it lived before it came home.
Lake Valencia drainage in northern Venezuela. Moderately hard slightly alkaline water — softer than most South American characins. Vegetated lake margins with sandy substrate.
Insect larvae, small crustaceans, plant matter, biofilm. Genuinely omnivorous — they pick at soft algae and plants more than most tetras.
Lake Valencia habitat is heavily impacted by human activity — wild populations are reduced. Captive-bred stock is plentiful and stable.
How they pair, reproduce, and grow.
Mature males develop dramatically extended dorsal and anal fin rays — like flowing ribbons. Females stay rounder with shorter fins. Juvenile males look identical to females; the difference emerges over 6–9 months.
Egg scatterers in soft acidic water. Drop pH to 6.0–6.5, temperature 26 °C, dense moss. Adults eat eggs aggressively — separate after spawning. Fry need infusoria for the first week.
The named cultivars and the lookalikes worth flagging.
Wild type only. Lake Valencia origin is sometimes called the 'Valencian diamond' but it's the same species.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Diamond Tetra (Moenkhausia pittieri) needs a minimum tank of 100 L. They live in the mid water column and should be kept in groups of 6+, so a longer footprint matters more than depth.
Target 24–28 °C, pH 6.0–7.5, and 4–15 dGH hardness. Acclimate slowly when moving them between water sources.
Shrimp safety: Mostly (may eat shrimplets). Plant safety: Yes.
Diamond Tetra are omnivore. Flake, micro pellets, frozen daphnia, bloodworms, occasional plant matter.
On Fin & Stem's 1–5 difficulty scale this species rates 2/5. Forgiving, beginner-friendly once the tank is cycled. Breeding difficulty: medium.
Typical lifespan in a well-maintained tank is 4–6 years.
A planted tank is a system. Pair this fish with one entry from each other pillar to plan the whole scape.
