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Marbled Headstander

Abramites hypselonotus

A massive, beautifully banded headstander with a highly arched back. Swims constantly at a downward angle. Unlike its peaceful cousins, it is a boisterous, nippy colossus (15 cm) that will mercilessly devour and destroy any live plants in the aquarium.

Taxonomy
Class:Actinopteri
Order:Characiformes
Family:Anostomidae
Genus:Abramites
Species:Abramites hypselonotus

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Water Temperature

23 - 27 °C

pH Value

6 - 7.5

Water type

Freshwater

Adult size

14 cm

Minimum tank volume

>= 100 L

Minimum group

>= 1

GH

4 - 15 dGH

KH

2 - 7 dKH

TDS

80 - 295 ppm

Conductivity

125 - 461 uS/cm

Species description

Geographical Origin and Habitat: Endemic to the Amazon and Orinoco river basins in South America. Prefers fluvial areas with weak to moderate current, abundant with submerged marsh vegetation and dense tangles of branches and roots.
Taxonomy and Morphology: Characin belonging to the Anostomidae family. Reaches 14 cm (5.5 inches). Distinguished by its high, laterally compressed body, with a peculiar and conspicuous sail-like dorsal fin that enhances its oblique head-down swimming (Headstander).
Social Behavior: Schooling animal with strong hierarchical tendencies; keeping single specimens makes them fearful or strangely aggressive. It is imperative to form schools of at least 6-8 individuals to disperse the harmless intraspecific skirmishes for dominance.
Coloration and Sexual Dimorphism: Silvery or pale yellow background crossed by vigorous and faded dark gray or brown vertical bands, irregular and "marbled". The lower fins can show amber or orange reflections. Mature females are distinctly thicker and swollen compared to males.

Care, breeding and tankmates

Aquarium Setup: Long tank (at least 120 cm / 4 feet). Set up with sandy bottoms, huge curved woods and smooth rocks. Warning: it will brutally devour almost every live plant; use only very robust epiphytes (Anubias, Microsorum) tenaciously tied to the woods, or synthetic vegetation.
Diet and Feeding: Tireless vegetarian with omnivorous hints. Requires a massive and continuous vegetable intake: blanched lettuce leaves, zucchini, shelled peas, spirulina and wafers for herbivorous fish. Supplement occasionally with bloodworms and krill.
Water Quality: Robust and adaptable, but demands stability. Temperature 23-27°C (73-81°F), pH tendentially neutral or slightly acidic (6.0 - 7.5), medium hardness (GH 4-15). The water must be excellently filtered but without stormy currents unbearable for its swimming.
Compatibility and Cohabitation: Relatively peaceful with species of similar size and temperament. Excellent companion for large loricariids, peaceful earth-eating cichlids (Geophagus) and generously sized tetras. Avoid slow, timid tankmates or those with long veil fins (it might nip them).
Aquarium Breeding: Extremely rare in captivity. Requires huge tanks, very strong thermal and osmotic shocks simulating the rainy season. They are egg scatterers, do not provide parental care and will greedily feast on their own offspring if not removed.
Risks and Diseases: Very robust; however, if deprived of the vegetable component in the diet it will face lethal intestinal obstructions or nutritional deformations. Suffers acute intoxication in case of sudden spikes in ammonia or nitrites.

Geographic Origin and Distribution

Endemic to the Amazon and Orinoco river basins in South America. Prefers fluvial areas with weak to moderate current, abundant with submerged marsh vegetation and dense tangles of branches and roots.

Origin

Amazon, Orinoco, and Guianas

Fish profile

Temperament
No verified data available
Diet
No verified data available
Life expectancy
No verified data available
Adult size
14 cm
The catalog's scalar value is 14 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 14 cm for this species, recorded as total length (TL). The taxonomic record consulted is Abramites hypselonotus (v25.04); male or unsexed record. These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
Sex ratio
No verified data available
Feeding frequency
No verified data available
Bioload
Medium
The single-adult profile is classified as medium bioload. The bioload-v2 rubric deterministically assigns this class from the verified maximum length of 14 cm; it is a catalog management category, not a direct measurement of waste output.
Flow
No verified data available
Jump risk
No verified data available
Reproduction
No verified data available
Compatibility & tankmates
No verified data available
Tank level
No verified data available

Window to the official scientific data of the species

Data synced on: 06/15/2026

Scientific Parameters & Models

Trophic level
2.9 ± 0.33 se
Resilience
High (less than 15 months)
Phylogenetic uniqueness (PD50)
0.75
Bayesian Length-Weight
a = 0.01072, b = 3.08
VulnerabilityLow vulnerability (10 / 100)

Image gallery

Licensed images linked to the species or, when marked, to the closest representative taxon.

Related species

Recommendations grouped by close relatives, companion choices, and similar care.

Last updated: 08/10/2026
Marbled Headstander (Abramites hypselonotus) Care Guide & Tank Setup | Atlarium