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Leporinus arcus — Lipstick Leporinus

Lipstick Leporinus

Leporinus arcus

A massive, powerful Amazonian colossus (up to 40 cm / 15+ inches) famous for its bright, fire-red 'lipstick' mouth. An unrelenting herbivore and ferocious fin-nipper that requires enormous tanks, bulletproof lids, and monster-fish tankmates.

Water Temperature

22 - 28 °C

pH Value

6 - 7.5

Water type

Freshwater

Tank level

Bottom and middle

Adult size

40 cm

Minimum tank volume

>= 500 L

Minimum group

8

GH

2 - 15 dGH

KH

1 - 7 dKH

TDS

40 - 295 ppm

Conductivity

63 - 461 uS/cm

Species description

Geographical Origin and Habitat: Major river systems of the Orinoco (Venezuela, Colombia) and Guianese rivers. Inhabits main river channels, rocky flooded zones, and areas with strong flow, grazing heavily on algae-covered rocks and submerged fruits.
Taxonomy and Morphology: An absolute giant within the Anostomidae family, reaching 35-40 cm (14-16 inches) in captivity. Built like a muscular torpedo for immense swimming power. Features the iconic 'hare-mouth' equipped with sharp, shearing incisor teeth designed to cut vegetation and crush seeds.
Social Behavior: An indefatigable, restless, and dominant swimmer. Constantly patrols the tank, investigating and biting objects. Like the Banded Leporinus, it is a notorious and vicious fin-nipper, easily shredding the fins of slower tankmates. Highly aggressive and intolerant toward its own kind in confined spaces.
Coloration and Sexual Dimorphism: Subtle but featuring a striking focal point. The body is a metallic olive/gold. Three prominent, large black blotches (or a dashed line) run along the lateral mid-section. Its namesake feature is its mouth: the lips and entire front snout are stained a brilliant, glowing FIRE RED (the 'lipstick'). Unpaired fins are also flushed with intense red/orange.

Care, breeding and tankmates

Aquarium Setup: Exclusively for Jumbo Tanks (MINIMUM 180-200 cm / 6-7 feet length, 200+ gallons). Will eat literally any live plant down to the roots. Scape the tank like a major riverbed: massive smooth boulders, giant driftwood, and sand. IMPORTANT: Driftwood and rocks must be heavy and secure, as a 40-cm Leporinus will violently ram and move light decor looking for food. A HEAVY, INDUSTRIAL-STRENGTH LID is mandatory to contain its massive jumping power.
Diet and Feeding: Voracious Herbivore with omnivorous tendencies. 70-80% of the diet MUST be vegetable matter to prevent fatal bloat. Feed thick slabs of zucchini, broccoli stalks, whole romaine lettuce, and jumbo pond-algae pellets daily. Supplement sparingly with large earthworms or whole shrimp. To tear food, they bite and perform violent 'death-rolls' (like a crocodile).
Water Quality: Extremely hardy. Adapts well to pH 6.0-7.5 and medium hardness. Temp 23-28°C (73-82°F). Given the massive volume of vegetable waste they excrete, industrial filtration and powerful wavemakers (for strong current) are strictly required.
Compatibility and Cohabitation: A strictly 'Monster Fish' species. Will swallow small fish and mercilessly mutilate slow/long-finned fish. House ONLY with large, heavily armored or aggressive tankmates that can stand their ground: Oscars, Pike Cichlids (Crenicichla), massive Geophagus, Arowanas, and jumbo Plecos. Never keep 2 or 3 together: keep either ONE solitary specimen or a massive school (8+) to disperse their lethal internal aggression.
Aquarium Breeding: Impossible in home aquaria.
Risks and Diseases: 1. SEVERE MUTILATION of tankmates' fins. 2. Physical destruction of tank decor, including biting through soft filter tubing/heaters. 3. Shattering lids or jumping out. 4. Fatal intestinal blockages if fed a carnivore (high-protein) diet.

Geographic origin and distribution

Major river systems of the Orinoco (Venezuela, Colombia) and Guianese rivers. Inhabits main river channels, rocky flooded zones, and areas with strong flow, grazing heavily on algae-covered rocks and submerged fruits.

Origin

Amazon, Orinoco, and Guianas

Fish profile

Temperament
Semi-aggressive
They are active and sometimes boisterous. Aggression is mostly directed at conspecifics. A large group helps reduce targeted bullying.
Diet
Omnivore
Leporinus arcus is an omnivore favoring plant matter. Feed them spirulina pellets and fresh vegetables. They will also eat small meaty foods.
Life expectancy
5-10 years
Adult size
40 cm
Sex ratio
Group
A specific sex ratio is not critical. Keep them in groups to disperse aggression. Sexing young individuals is very difficult.
Feeding frequency
Twice daily
Feed them twice a day. Offer small portions to prevent water fouling. They have a very healthy appetite.
Bioload
High
Leporinus arcus is a large and active fish. It produces a substantial amount of waste. Strong filtration is absolutely required.
Flow
Stagnant
They appreciate a moderate to strong water flow. Good circulation mimics their native rivers. Adequate surface agitation is also important.
Jump risk
Yes
The jump risk is incredibly high. They are powerful jumpers when startled. A heavy, tight-fitting lid is mandatory.
Reproduction
Oviparous
Breeding in captivity is exceedingly rare. They do not exhibit any parental care. Commercial breeding uses hormone injections.
Compatibility & tankmates
With caution
This species can be a fin-nipper. Keep them with robust, fast-moving fish. Do not keep them with slow species.
Tank level
Middle/Bottom
Leporinus arcus swims primarily in the middle levels. They need a lot of open swimming space. A long aquarium is highly recommended.

Scientific Parameters & Models

FishBase

Window to the official scientific data of the species

FishBase v25.04Data synced on: 06/15/2026
Trophic level
2.3 ± 0.1 se
Resilience
Medium (1.4 - 4.4 years)
Phylogenetic uniqueness (PD50)
0.5
Bayesian Length-Weight
a = 0.01023, b = 3.04
VulnerabilityLow to moderate vulnerability (30 / 100)