AquaLibs presents AquaRank Discover the world’s leading aquascapers

Explore transparent rankings built from published results across the world’s leading aquascaping contests.

Metynnis maculatus (Spotted Silver Dollar)

Overview

The Spotted Silver Dollar (Metynnis maculatus), often referred to in the German trade as the "gepunkteter scheibensalmler raritaet" due to its uncommon availability, is a spectacular freshwater fish belonging to the family Serrasalmidae. Unlike the common silver dollar, this species boasts a beautiful, speckled pattern that makes it a highly sought-after prize for aquarists. They are active, schooling fish that bring a lot of life and shimmering movement to large community aquariums.

Image of gepunkteter scheibensalmler metynnis maculatus raritaet

Distribution and Habitat

This species is native to the tropical river basins of South America, particularly found in the Amazon and Paraguay river systems. They naturally inhabit heavily vegetated river tributaries, flooded forests, and slow-moving waters where they can easily forage for plant matter and find refuge among submerged roots and branches.

Description of Spotted Silver Dollar

Body shape:

They possess a highly laterally compressed, disc-like body that is nearly round, allowing them to navigate smoothly through dense underwater vegetation.

Color:

The base coloration is a brilliant metallic silver, heavily patterned with distinctive black or dark grey spots along the flanks. Males often display a striking red or orange tint on their anal fins, especially during breeding.

Barbels:

This species does not possess any barbels.

Snout:

The snout is short and blunt, featuring a slightly undershot jaw equipped with sharp teeth perfectly evolved for shearing tough plant material.

Eyes:

They have relatively large eyes, which help them navigate and spot predators in the dimly lit, tannin-stained waters of their natural habitat.

Fins:

The fins are generally translucent with subtle silver or grey hues. The anal fin of adult males is elongated and frequently edged with a vivid red or orange margin.

The Tail:

The caudal (tail) fin is deeply forked and muscular, providing the fish with the ability to execute rapid bursts of speed when startled.

Temper

The Spotted Silver Dollar is a peaceful but somewhat skittish fish. They are easily startled by sudden movements or turning on bright tank lights abruptly. Despite their relation to piranhas, they are gentle giants that will not bother tank mates that are too large to fit in their mouths.

Sociality

They are highly gregarious and must be kept in groups of at least five or more individuals. When kept in isolation or pairs, they become extremely stressed and reclusive. In a proper school, they display their natural, confident schooling behaviors.

Activity

These are active, mid-level swimmers that will constantly cruise back and forth across the aquarium during daylight hours. Their synchronized swimming in a school is a mesmerizing sight.

Keeping and Caring for Spotted Silver Dollar

Tank size:

Due to their adult size and active schooling nature, a minimum tank size of 75 gallons (approx. 280 liters) is required, though a 100+ gallon tank is highly recommended for a full-sized adult school.

Water Parameters:

Temperature

Maintain a stable water temperature between 24-28°C (75-82°F).

pH

They thrive in slightly acidic to neutral water, with a pH range of 6.0 to 7.5.

Hardness

Soft to moderately hard water is ideal, ranging from 4 to 15 dGH.

Ammonia, Nitrite, Nitrate

Ammonia and Nitrite must always be at 0 ppm. Nitrates should be kept below 20 ppm through regular water changes and excellent filtration.

Lighting

Moderate to dim lighting is preferred. Bright lighting can make them skittish, so floating plants (if they don't eat them) or a blackwater setup can help diffuse the light.

Water flow

A moderate water flow mimics their natural riverine environment and provides adequate oxygenation without exhausting the fish.

Decorations and Plants

Decorate with smooth river rocks, large pieces of driftwood, and tangled roots to provide hiding spots. Be warned: Spotted Silver Dollars are voracious herbivores. Most live plants will be eaten. If you want greenery, use robust plastic plants or try very tough live plants like Anubias or Java Fern, though even these are not entirely safe.

Diet

They are primarily herbivorous. In the aquarium, their diet should consist largely of vegetable matter. High-quality spirulina flakes, algae wafers, and herbivore pellets should form the staple of their diet. They will also eagerly accept blanched vegetables such as zucchini, cucumber, spinach, and romaine lettuce. Occasional protein treats like bloodworms or brine shrimp can be offered.

Some Feeding Tips

Provide fresh greens regularly to deter them from constantly grazing on any live plants you attempt to keep. Feeding them small amounts twice a day is optimal to match their active metabolism.

Breeding

Breeding the Spotted Silver Dollar in captivity is possible but requires a large, dedicated breeding tank. They are egg-scatterers that provide no parental care. To induce spawning, condition the pair or group with high-quality foods and perform a large water change with slightly cooler, softer water. The female will release hundreds of eggs among fine-leaved plants (or spawning mops), which the male will fertilize. Adults should be removed post-spawning to prevent them from eating the eggs. Fry hatch in a few days and can be fed infusoria and newly hatched brine shrimp.

Conclusion

The Spotted Silver Dollar (Metynnis maculatus) is a magnificent, peaceful schooling fish that acts as a fantastic centerpiece for large freshwater aquariums. While their appetite for plants requires some careful planning regarding tank decor, their striking spotted pattern, hardy nature, and active schooling dynamics make this "rarity" an absolute joy to keep for any dedicated aquarist.

Fish info

  • Care level: Moderate
  • Temperament: Peaceful
  • Adult size: 15-18 cm
  • Life expectancy: 8-10 years
  • Fish type: Characin
  • Temperature : 24-28°C
  • pH: 6.0-7.5
  • Color Form: Black, Red, Silver
Leave your comments
Latest on Fishs
  • Blue Acara (Aequidens pulcher)

    Blue Acara (Aequidens pulcher)

    Moderate
    South American freshwater cichlid
    The supplied label identifies these fish as Blue Acara, Aequidens pulcher, a South American freshwater cichlid often placed in the genus Andinoacara in current aquarium literature. The photograph is consistent with a blue acara, although a definitive identification cannot be confirmed from one image alone. This pair requires a spacious aquarium, stable water quality, hiding places and careful observation during breeding, when territorial behavior becomes stronger.
  • Julidochromis transcriptus: Black-and-White Slender Cichlid

    Julidochromis transcriptus: Black-and-White Slender Cichlid

    Moderate
    Lake Tanganyika rock-dwelling cichlid
    Julidochromis transcriptus is a small rock-dwelling cichlid from Lake Tanganyika, recognized by its compact, elongated body and irregular black-and-white pattern. It is a territorial cave dweller that is best kept as an established pair in a carefully structured aquarium. The supplied fish are identified as a DNZ pair, although sex, collection locality, and precise geographic form cannot be verified from the supplied material alone.
  • Azur Cichlid (Sciaenochromis fryeri) Care Guide

    Azur Cichlid (Sciaenochromis fryeri) Care Guide

    Moderate
    Lake Malawi haplochromine cichlid
    The Azur cichlid is commonly sold as Sciaenochromis fryeri, a predatory haplochromine cichlid from Lake Malawi. Mature males develop vivid electric-blue coloration, while females and juveniles are generally less intensely colored. This fish is moderately aggressive and needs a spacious aquarium with rocky structure, alkaline, mineral-rich water, and carefully selected tank mates. The supplied source describes a DNZ pair, but sex and exact locality cannot be confirmed from the images alone. Identification confidence is therefore good but not absolute.
  • Marble Angelfish (Pterophyllum scalare)

    Marble Angelfish (Pterophyllum scalare)

    Moderate
    South American freshwater cichlid
    The marble angelfish is a captive-bred color form of Pterophyllum scalare, a tall-bodied South American cichlid valued for its elegant fins and distinctive irregular black patterning. It needs a mature, spacious aquarium with excellent water quality, warm water and suitable tank mates. Although generally manageable, adults establish territories and may become assertive when pairing or spawning. The supplied source identifies two marble angelfish; exact lineage and strain details cannot be confirmed from the available information.
  • Gold Angelfish, Pterophyllum scalare

    Gold Angelfish, Pterophyllum scalare

    Moderate
    Freshwater South American cichlid
    The Gold Angelfish is an ornamental colour form of Pterophyllum scalare, a tall-bodied South American cichlid valued for its graceful movement and parental care. It needs a mature, spacious aquarium with substantial vertical clearance, stable warm water and carefully chosen tank mates. The supplied source identifies two fish as Gold Angelfish, although the accompanying images show several angelfish colour and fin forms, so the exact appearance of the supplied specimens cannot be confirmed from the images alone.
  • Zebra Angelfish (Pterophyllum scalare)

    Zebra Angelfish (Pterophyllum scalare)

    Moderate
    South American freshwater cichlid
    The Zebra Angelfish is a selectively bred form of Pterophyllum scalare, recognised by a silvery body with several dark vertical bars and the tall, laterally compressed shape typical of freshwater angelfish. The supplied images also show other angelfish colour forms, so the exact appearance of the listed pair cannot be confirmed from the image set alone. This South American cichlid is generally manageable for experienced community keepers, but its size, territorial breeding behaviour and need for a tall aquarium should be planned for carefully.
  • Black Angelfish (Pterophyllum scalare)

    Black Angelfish (Pterophyllum scalare)

    Moderate
    South American freshwater cichlid
    The supplied record identifies two black angelfish, most likely a domestic color form of Pterophyllum scalare. The photographs show several angelfish color patterns, so they should not be treated as proof that every pictured fish is black or that all belong to the same strain. Black angelfish retain the tall, laterally compressed body and extended fins typical of freshwater angelfish. They need a tall, mature aquarium, stable warm water, a varied diet, and carefully selected tank mates.
  • White Marble Angelfish (Pterophyllum scalare)

    White Marble Angelfish (Pterophyllum scalare)

    Moderate
    Freshwater cichlid
    The white marble angelfish is a selectively bred aquarium color form of Pterophyllum scalare, a tall-bodied South American cichlid valued for its elegant fins and distinctive irregular dark marbling. It is generally peaceful when young but can become territorial, especially when paired for spawning. Successful care depends on a tall aquarium, excellent water quality, suitable tank mates, and a varied carnivorous-omnivorous diet. The exact genetic strain shown cannot be confirmed from photographs alone.
  • Freshwater Angelfish Mix (Pterophyllum scalare)

    Freshwater Angelfish Mix (Pterophyllum scalare)

    Moderate
    Freshwater cichlid
    Freshwater angelfish are tall-bodied South American cichlids valued for their graceful movement and wide range of captive color forms. The supplied source identifies a mixed group as Pterophyllum scalare; the photographs show several forms, including striped, black, orange, white, silver and blue-toned fish. They are manageable for experienced beginners, but their adult height, territorial breeding behavior and tendency to eat small tank mates require thoughtful aquarium planning.
  • Leopard Angelfish (Pterophyllum scalare)

    Leopard Angelfish (Pterophyllum scalare)

    Moderate
    South American freshwater cichlid
    The leopard angelfish is a domestic color form of Pterophyllum scalare, a tall-bodied freshwater cichlid from tropical South America. Its silver to yellowish body is marked with irregular dark spots or broken vertical bars, although pattern intensity varies with age, mood and breeding line. It is generally peaceful in a suitably spacious community aquarium, but pairs become territorial when spawning. This fish needs warm, clean water, generous vertical swimming space and tank mates too large to swallow.
  • Yellow Labidochromis (Labidochromis caeruleus)

    Yellow Labidochromis (Labidochromis caeruleus)

    Easy - Moderate
    Lake Malawi mbuna cichlid
    The Yellow Labidochromis is a bright yellow mbuna cichlid from Lake Malawi. Labidochromis caeruleus is generally manageable for an African cichlid, but it remains territorial and needs hard, alkaline water, rockwork, and carefully chosen companions. The supplied source identifies two fish as a pair; sex and pair bonding cannot be confirmed from the available images. This species is an adaptable algae grazer, a maternal mouthbrooder, and a rewarding choice for an appropriately planned Malawi cichlid aquarium.
  • Blue Pearl Angelfish (Pterophyllum scalare)

    Blue Pearl Angelfish (Pterophyllum scalare)

    Moderate
    Freshwater cichlid
    The Blue Pearl Angelfish is a selectively bred colour form of Pterophyllum scalare, the freshwater angelfish. Its laterally compressed body, extended fins and tall profile make it a striking inhabitant of a planted community aquarium. The supplied trade label supports identification as this species and colour form, although individual colour intensity can vary. It requires warm, stable, clean water, generous vertical swimming space and thoughtful tank-mate selection, especially as adults become territorial when pairing or spawning.
  • Villavicencio Dwarf Cichlid Apistogramma macmasteri

    Villavicencio Dwarf Cichlid Apistogramma macmasteri

    Moderate
    South American dwarf cichlid
    Apistogramma macmasteri, commonly called the Villavicencio dwarf cichlid, is a small South American cichlid associated with the Río Orinoco drainage of Colombia. It is valued for its compact size, elaborate finnage and interesting courtship behavior. A bonded pair can be kept in a carefully structured aquarium with soft, clean water, sand, cover and several potential spawning sites. Although manageable for an experienced community aquarist, territorial behavior increases during breeding, so tank layout and tankmate selection are important.
  • Neolamprologus leleupi (Tanganyika Golden Cichlid)

    Neolamprologus leleupi (Tanganyika Golden Cichlid)

    Moderate
    Lake Tanganyika rock-dwelling cichlid
    Neolamprologus leleupi is a small, brightly coloured cichlid endemic to Lake Tanganyika in East Africa. It inhabits rocky coastal areas and uses crevices for shelter, feeding and spawning. Despite its modest size, it can be strongly territorial, particularly when paired or breeding. The supplied source identifies these fish as a golden colour form and a pair, although sex cannot be confirmed reliably from the image alone. Successful care depends on alkaline, mineral-rich water, abundant rockwork and carefully chosen tank mates.
  • Maingano Cichlid (Melanochromis cyaneorhabdos)

    Maingano Cichlid (Melanochromis cyaneorhabdos)

    Moderate - Difficult
    Lake Malawi mbuna cichlid
    The Maingano, or Johanni Maingano, is a Lake Malawi mbuna recognized for its intense steel-blue body and dark horizontal markings. The supplied label combines “Johanni” with the scientific name Melanochromis cyaneorhabdos; these are distinct species, so identification should be confirmed from the seller or locality. This territorial mouthbrooding cichlid needs hard, alkaline water, abundant rockwork, a predominantly algae-based diet, and careful stocking to limit aggression.
  • Red Chocolate Gourami (Sphaerichthys vaillanti)

    Red Chocolate Gourami (Sphaerichthys vaillanti)

    Difficult
    Blackwater labyrinth fish
    The red chocolate gourami, Sphaerichthys vaillanti, is a specialized Southeast Asian labyrinth fish suited to mature, soft, acidic blackwater aquariums. It is peaceful but easily stressed by bright lighting, strong currents and boisterous tank mates. The supplied source identifies these fish as a pair; sex and exact identity cannot be confirmed from the image alone, so identification should be checked against a reliable specimen reference. Stable water quality, cover and a varied small-food diet are central to long-term success.