Redhook Myleus
Myloplus rubripinnis
The Redhook Myleus (Myloplus rubripinnis) is the 'Premium' and noticeably larger version of the common Silver Dollar. This imposing disc-shaped characin sports a brilliant silvery livery accentuated, in adult males, by reddish or golden hues on the flanks. Its unmistakable feature is the anal fin: a majestic and pronounced hook-shaped lobe tinted a vibrant ruby red edged with black. Reaching 25 cm (10 inches), this vigorous swimmer requires colossal setups, but repays the effort with a regal presence in XXL South American tanks.
Temperatura da água
23 - 28 °C
Valor de pH
5.5 - 7.5
Tipo de água
Água doce
Nível do tanque
Superfície e meio
Tamanho adulto
25 cm
Volume mínimo do tanque
>= 600 L
Grupo mínimo
>= 5
GH
4 - 12 dGH
KH
2 - 6 dKH
TDS
80 - 240 ppm
Condutividade
125 - 375 uS/cm
Descrição da espécie
Geographical Origin and Habitat: Amazon river basins (Orinoco, Rio Negro, etc.) in South America. Populates dense oxbow lakes covered by roots and flooded forests where plant cover is very heavy.
Taxonomy and Morphology: Redhook Silver Dollar (Myloplus rubripinnis / ex Myleus rubripinnis). Vegetarian "Pacu/Piranha" of impressive size. It has a flattened silver disk, but boasts a sickle or hook-shaped anal fin.
Social Behavior: Titanic Gregariousness (Schooling). Unlike small fish, fear in this beast translates into sprints that break heaters. Keeping a school of at least 5 mitigates panic and stops the group from breaking apart.
Coloration and Sexual Dimorphism: Shiny silver metallic shield (more ash-gray in adulthood). The hallmark is the huge fleshy anal hook of an intense carmine red (Red-hook). Males develop extended filamentous dorsal fins and a fringed anal lobe (females have a straight, clean red hook).
Cuidado, criação e companheiros de tanque
Aquarium Setup: Monster Tank (200+ cm / 80+ inches, 700 Liters / 185 Gallons). Do not waste money on furnishings: sharp branches will flay them in their sprints and they will destroy, eat or uproot ANY existing aquatic plant (even Anubias and Java Ferns or plastic!).
Diet and Feeding: Vegetable-mincing machine (Frugivore/Herbivore). They have powerful jaws with crossed flat teeth born to break hard pits. Feed massively with zucchini, peas, cucumbers, blanched lettuce or vegetable feed for koi carps.
Water Quality: Moderately acidic water (preferably tannic to reassure them), but they are pollution machines (Critical Bio-load). They suck in huge amounts of food and produce gigantic feces; double external/pond external filters are essential.
Compatibility and Cohabitation: The perfect Dither-Fish for Super Cichlids. No South American or Central American cichlid (even Peacock Bass, Oscars or Jaguar Cichlids) can swallow this spiky silver flying saucer. Harmless to other species (if not tiny).
Aquarium Breeding: Virtually absent due to lack of space (only in zoos or indoor public pools). Couples release eggs that sink amid the school during the wet season.
Risks and Diseases: Glass-breaker from light explosion. The sudden turning on of the neons above their tank unleashes a 25 cm (10 inches), one-pound bullet against the front glass, causing the animal's skull to fracture or the glass to crack (use LED Sunrise/Sunset or dim lights).
Origem e distribuição geográfica
Amazon river basins (Orinoco, Rio Negro, etc.) in South America. Populates dense oxbow lakes covered by roots and flooded forests where plant cover is very heavy.
Origem
Amazônia, Orinoco e GuianasEuropa, Mediterrâneo e Ásia Ocidental
Perfil de peixe
- Temperamento
- Active
- They exhibit a generally peaceful and skittish temperament when kept in groups. However, they can be easily startled and may dash erratically. Providing ample swimming space and secure hiding spots keeps them calm.
- Dieta
- Herbivore
- They are primarily herbivorous, feeding heavily on aquatic vegetation in the wild. In the aquarium, they readily accept vegetable-based flakes and blanched zucchini. Their main diet must be plant-based to ensure proper digestion.
- Expectativa de vida
- 5-12 years
- Tamanho adulto
- 25 cm
- Proporção sexual
- School
- Adult males often display a more intensely colored and elongated anal fin. A specific male-to-female ratio is not strictly required for a community display. Keeping them in a large school balances their social interactions naturally.
- Frequência de alimentação
- Twice daily
- They should be fed two to three times daily to satisfy grazing habits. Offering smaller portions frequently is better than a single large meal. A steady supply of greens deters them from destroying robust plants.
- Carga biológica
- High
- The Redhook Myleus generates a high bioload due to its large adult size. A powerful and efficient filtration system is mandatory to keep parameters stable. Large, frequent water changes are necessary to remove significant metabolic waste.
- Fluxo
- Moderate
- They prefer moderate to strong water currents that simulate South American rivers. Good water circulation is important for their exercise and assists heavy filtration. Strategically placed powerheads encourage their natural schooling behavior.
- Risco de salto
- Yes
- As powerful and easily spooked fish, they pose a significant jumping risk. A tight, heavy-duty aquarium lid is absolutely necessary to prevent escapes. Care should be taken to avoid sudden movements during tank maintenance.
- Reprodução
- Oviparous
- Breeding in captivity is rare and requires a very large specialized setup. They are egg-scatterers that release large numbers of eggs among submerged vegetation. Commercial specimens are typically bred in massive outdoor ponds.
- Compatibilidade e companheiros de tanque
- Highly aggressive
- This species is peaceful but large, making it unsuitable for very small fish. They do best in groups of at least five individuals. Small fish that fit into their mouths might be eaten or stressed.
- Nível do tanque
- Top/Middle
- They are primarily active in the middle levels of the aquarium. They require plenty of unobstructed horizontal swimming space for their size. The mid-water region is their primary domain for cruising.
Modelos e parâmetros científicos
FishBase
Acesso aos dados científicos oficiais da espécie
FishBase v25.04Dados sincronizados em: 15/06/2026
- Nível trófico
- 2 ± 0 se
- Resiliência
- Alta (menos de 15 meses)
- Unicidade filogenética (PD50)
- 0.5001
- Relação bayesiana comprimento-peso
- a = 0.02344, b = 2.97
- VulnerabilidadeVulnerabilidade de baixa a moderada (32 / 100)



















































