Luetken's Tetra
Deuterodon luetkenii
Large and massive subtropical tetra with a lozenge-shaped body (can reach 6.5 cm). Bright greenish-gray with an evident shaded black band on the posterior half.
Température de l’eau
18 - 26 °C
Valeur du pH
6 - 7.5
Type d'eau
Eau douce
Niveau dans le bac
Milieu
Taille adulte
7 cm
Volume minimal du bac
>= 80 L
Groupe minimal
>= 6
GH
2 - 15 dGH
KH
2 - 10 dKH
TDS
50 - 325 ppm
Conductivité
78 - 508 uS/cm
Description de l'espèce
Geographical Origin and Habitat: Widely distributed in the Paraná and Paraguay river basins and coastal rivers of southern Brazil and Uruguay. Inhabits rocky streams, lagoons, and ponds in sub-tropical or temperate climates, facing major seasonal thermal shifts.
Taxonomy and Morphology: Deuterodon luetkenii. Among the giants of the genus (reaches 7 cm / 2.8 inches). Corpulent, barrel-shaped or elongated disc-shaped, similar in physiognomy to the Buenos Aires Tetra (H. anisitsi), very muscular and robust.
Social Behavior: Hyperactive and gregarious fish. Its size and frenetic swimming can intimidate quiet fish. Absolutely to be kept in a large school (at least 8) to vent the incessant intraspecific hierarchical skirmishes.
Coloration and Sexual Dimorphism: Silvery coloration and very large, almost mesh-like scales. The anal, caudal, and pelvic fins display a color from pale orange to rusty red. Females are noticeably more pot-bellied and taller than males.
Soins, reproduction et cohabitation
Aquarium Setup: Needs large and spacious aquariums (100+ cm / 40+ inches). Being omnivorous and destructive, it can eat soft-leaved plants: decorate with smooth rocks, mighty wood, Anubias, and Java Ferns. Strong water movement appreciated.
Diet and Feeding: Extremely voracious. Accepts everything: complete pellet foods, flakes, live food. It is essential to provide a large supply of plant matter (blanched spinach, zucchini, spirulina-based flakes) to satiate it.
Water Quality: "Teflon" fish, tolerates everything. Sub-tropical (cool) water species: ideal between 18°C and 24°C (64-75°F), never above 26°C (79°F) for long. pH between 6.0 and 7.5, tolerates moderately hard waters without problems.
Compatibility and Cohabitation: Never pair with shy or slow fish. Perfect for "unheated tanks" with other temperate fish: Corydoras paleatus, Gymnocorymbus ternetzi (Black Skirt Tetra), or large peaceful hardy Cichlids.
Aquarium Breeding: Prolific. Pairs, if fed abundantly, scatter hundreds of transparent eggs among bushes (or fake spawning plants). They are the worst predators of their offspring and must be moved instantly.
Risks and Diseases: Exceptionally long-lived and healthy. The only serious risk is keeping it constantly at 28-30°C (82-86°F): thermal stress will accelerate its metabolism to the point of exhaustion.
Origine et répartition géographiques
Widely distributed in the Paraná and Paraguay river basins and coastal rivers of southern Brazil and Uruguay. Inhabits rocky streams, lagoons, and ponds in sub-tropical or temperate climates, facing major seasonal thermal shifts.
Origine
Amérique du Sud hors Amazonie
Profil de poisson
- Tempérament
- Semi-aggressive
- The Deuterodon luetkenii is renowned for its peaceful, albeit somewhat shy and timid, temperament. They are highly social fish that absolutely depend on the presence of a sizable school for their confidence and well-being. When kept in sufficient numbers, they exhibit a lively and inquisitive nature, gracefully exploring the aquarium. However, if kept alone or in very small groups, they will likely become withdrawn, pale, and prone to hiding constantly.
- Régime alimentaire
- Omnivore
- In its natural habitat, the Deuterodon luetkenii is a micro-predator that primarily feeds on tiny invertebrates and zooplankton. In captivity, they eagerly accept a staple diet of high-quality crushed flakes and micro-pellets. To support their overall health and promote optimal development—such as their prominent humeral spot and robust body shape—their diet should be frequently supplemented with live or frozen foods like Daphnia and cyclops. A diverse nutritional profile is crucial for maintaining a robust immune system.
- Espérance de vie
- 3-5 years
- Taille adulte
- 7 cm
- Ratio des sexes
- School
- When establishing a school of Deuterodon luetkenii, maintaining a relatively balanced mix of males and females is beneficial. Males generally exhibit a slimmer profile and often display their characteristic silver body with subtle tints more intensely compared to the plumper females. Having slightly more females than males can help dissipate any minor intra-species sparring when males display for dominance. Ultimately, keeping a large enough overall group size is more critical than the exact sex ratio.
- Fréquence d'alimentation
- Twice daily
- For optimal health, the Deuterodon luetkenii should be fed small portions two to three times a day. Only offer an amount of food that the school can completely consume within two minutes to prevent water fouling. Overfeeding is a common issue with small characins, so strict portion control must be maintained. This frequent, small-meal approach closely mimics their continuous foraging behavior in the wild.
- Charge biologique
- Low to Medium
- The Deuterodon luetkenii contributes a very low bioload to the aquarium ecosystem due to its small size. This makes them highly suitable for densely planted nano tanks and community setups alike. Despite their low waste production, maintaining a strict schedule of weekly water changes is highly recommended. A standard, high-quality biological filtration system will easily process the minimal waste generated by a healthy school.
- Courant
- Stagnant
- The Deuterodon luetkenii naturally inhabits slow-moving streams and flooded forest areas, meaning they prefer gentle water flow in the aquarium. Strong currents from overpowered filters can quickly exhaust these small fish and cause chronic stress. A sponge filter or a baffled hang-on-back filter is usually the most appropriate choice to provide oxygenation without turbulent flow. Providing dense clusters of aquatic plants will also give them tranquil resting spots.
- Risque de saut
- Yes
- Like many similarly sized characins, the Deuterodon luetkenii presents a moderate jumping risk, especially when initially introduced or startled. A secure, tight-fitting aquarium lid or a glass canopy is absolutely essential to prevent accidental losses. Employing floating plants such as Salvinia or Amazon Frogbit can provide overhead cover, which significantly reduces their skittishness. Stable water parameters and a peaceful environment will also minimize this leaping behavior.
- Reproduction
- Oviparous
- Breeding the Deuterodon luetkenii requires a separate, dimly lit breeding tank equipped with soft, slightly acidic water. They are typical egg-scatterers that exhibit no parental care whatsoever, and they will readily consume their own eggs if left in the breeding tank. Spawning typically occurs among fine-leaved plants, after which the adults must be immediately removed. The microscopic fry require infusoria or specialized liquid foods until they are large enough to eat freshly hatched brine shrimp.
- Compatibilité et compagnons
- Semi-aggressive
- As a peaceful schooling species, the Deuterodon luetkenii thrives when kept in a vibrant community aquarium. They require the security of a group, so maintaining them in schools of at least eight individuals is essential. Excellent tank mates include small rasboras, Corydoras catfish, and other equally peaceful characins. Aggressive, large, or excessively boisterous fish should be strictly avoided to prevent them from becoming stressed or preyed upon.
- Niveau dans le bac
- Middle
- The Deuterodon luetkenii is an active swimmer that primarily occupies the mid to upper levels of the aquarium water column. They deeply appreciate having a large, open swimming space in the center of the tank to school properly. They will often dart around the middle strata during the day, occasionally diving to the substrate during feeding times. Tall background plants and floating vegetation help them feel secure in these preferred swimming zones.
Modèles et paramètres scientifiques
FishBase
Fenêtre sur les données scientifiques officielles de l’espèce
FishBase v25.04Données synchronisées le : 15/06/2026
- Niveau trophique
- 3,2 ± 0,4 se
- Résilience
- Élevée (moins de 15 mois)
- Singularité phylogénétique (PD50)
- 0.5
- Relation bayésienne longueur-poids
- a = 0.0123, b = 3.1
- VulnérabilitéVulnérabilité faible (10 / 100)
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