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Myleus rubripinnis, commonly known as the Redhook Myleus, is a species of freshwater fish belonging to the family Serrasalmidae. It is characterized by its distinctive red-orange anal fin and often a red-orange adipose fin, contrasting with its silvery, disc-shaped body. These fish are primarily herbivorous, feeding on plant matter, fruits, and seeds, and are known for their schooling behavior in their natural habitats. They are popular in the aquarium trade due to their striking coloration and relatively peaceful demeanor compared to their piranha relatives.
Physical Characteristics
- Body shape
- compressed
- Coloration
- Silvery body, often with a faint iridescent sheen. The most distinguishing feature is the bright red to orange coloration on the anal fin, and often on the adipose fin. Some individuals may exhibit a reddish tint on the caudal fin base or operculum. Juveniles may have dark spots or bars that fade with age.
- Scale type
- cycloid
- Mouth position
- terminal
- Distinctive features
- Bright red to orange anal fin, Often red to orange adipose fin, Deep, disc-shaped body, Large, rounded eyes, Small, incisor-like teeth adapted for herbivory
- Dorsal fin
- Single, relatively tall dorsal fin, typically clear to slightly dusky.
- Tail fin
- Forked caudal fin, usually clear to slightly dusky, sometimes with a reddish base.
- Pectoral fin
- Clear, relatively small pectoral fins.
- Distinctive fins
- The anal fin is notably elongated and brightly colored red to orange, extending along a significant portion of the ventral body. The adipose fin, when present, is also often red or orange.
Identification Tips
Anal Fin Coloration
The most reliable identifier is the vibrant red to orange anal fin. This color is usually intense and covers most of the fin.
Adipose Fin Coloration
Presence of a red or orange adipose fin (a small, fleshy fin between the dorsal and caudal fins) further confirms identification, though its intensity can vary.
Body Shape
Its deep, laterally compressed, disc-like body is characteristic of the Myleus genus.
Dentition
While difficult to observe without handling, their small, incisor-like teeth are indicative of their herbivorous diet and differentiate them from carnivorous piranhas.
Habitat
- Water type
- freshwater
- Depth
- Typically found in shallow to moderately deep waters, often near submerged vegetation or fallen trees.
- Environment
- Inhabits clear to blackwater rivers, streams, floodplains, and flooded forests. Prefers areas with moderate to slow currents and abundant aquatic or riparian vegetation. Often found in schools.
- Geographic range
- Native to South America, primarily found in the Amazon and Orinoco River basins, including countries such as Brazil, Peru, Colombia, Venezuela, and Guyana.
Aquarium Information
- Care level: intermediate
- Temperament: semi-aggressive
- Diet: herbivore
- Minimum tank size: 180 gallons
- Temperature: 74-82°F (23-28°C)
- pH level: 6.0-7.5
- Hardness: 5-15 dGH
- Compatibility: Best kept in groups of 5 or more with other large, peaceful to semi-aggressive fish. Avoid keeping with very small or fin-nipping species. Can be housed with other large characins, large cichlids, and some catfish species.
- Special requirements: Requires a spacious aquarium with strong filtration due to their size and waste production. Provide plenty of open swimming space, as well as some hiding spots created by driftwood and robust plants (they will eat softer plants). A varied diet rich in vegetable matter is crucial.
Wild Information
- Conservation status: least concern
- Seasonality: Breeding typically occurs during the rainy season in their native habitats, when water levels are high and food is abundant.
- Market price: Varies, generally moderate for aquarium trade specimens.
- Commercial importance: medium
- Taste: Mild, somewhat flaky white flesh.
- Texture: Firm, white meat.
- Cooking methods: fried, baked, grilled, steamed
- Nutritional value: Good source of protein and omega-3 fatty acids, typical of freshwater fish.
Key Facts
Herbivorous Dietinteresting
Despite being related to piranhas, Redhook Myleus are primarily herbivorous, feeding on fruits, seeds, and plant matter.
Schooling Behaviorbehavior
In the wild, these fish form large schools, which provides safety in numbers against predators.
Misnomerfunny
They are sometimes mistakenly called 'Redhook Piranhas' due to their family relation, but their diet and temperament are vastly different.
Aquarium Longevityinteresting
With proper care, Redhook Myleus can live for 10-15 years or more in an aquarium setting.
Safety Information
Handle with care- Safety level: caution
- Venomous: No
- Edibility: edible
- Handling notes: While not venomous, Myleus rubripinnis can deliver a painful bite if provoked, especially larger specimens, due to their strong jaws and incisor-like teeth. Handle with care, preferably using a net, and avoid direct contact with the mouth. Their dorsal and anal fin spines can also be sharp.
Similar Species
Silver Dollar
Metynnis argenteus
Metynnis argenteus typically lacks the prominent red coloration on the anal and adipose fins. Its body is generally more uniformly silvery, and it often has a more rounded, less elongated anal fin.
Black-barred Myleus
Myleus schomburgkii
Myleus schomburgkii is distinguished by a prominent vertical black bar or blotch on its flanks, which M. rubripinnis lacks. While M. schomburgkii can also have red fins, the black bar is a key differentiator.
Red-bellied Piranha
Pygocentrus nattereri
Despite superficial similarities in body shape and red coloration, P. nattereri has a much more robust jaw with sharp, triangular teeth designed for shearing flesh, and a more aggressive temperament. M. rubripinnis has smaller, flatter, incisor-like teeth for plant matter.
Scientific Classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Actinopterygii
- Order
- Characiformes
- Family
- Serrasalmidae
- Genus
- Myleus
- Species
- rubripinnis
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