Gold Tetra

Quick summary

The Gold Tetra (Hemigrammus rodwayi) is a hardy, peaceful shoaling fish well suited to community aquariums, making it an excellent choice for both beginners and experienced fishkeepers. Its subtle golden shimmer and undemanding care requirements mean it fits comfortably into most soft to moderately hard water setups, though its famous metallic colouration has a surprising and widely debated origin story that sets it apart from almost every other tetra in the hobby.

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Last researched and fact-checked: June 2025.

• Introduction
• Quick Stats
• Appearance
• Natural habitat
• Tank size and setup
• Water parameters
• Filtration and equipment
• Diet and feeding
• Behaviour and temperament
• Tank mates
• Breeding
• Common diseases and health
• Frequently asked questions
• Related guides

Introduction

The Gold Tetra, Hemigrammus rodwayi, was first described by Durbin in 1909 and belongs to the family Characidae. It hails from the coastal river systems and floodplain habitats of northern South America, primarily in Guyana, Suriname, and French Guiana, with some populations also reported from parts of the lower Amazon basin in Brazil. In the aquarium hobby it has been a recognisable, if sometimes underappreciated, presence for decades, often overshadowed by more vividly coloured relatives like the Neon Tetra or Cardinal Tetra.

What makes Hemigrammus rodwayi genuinely unusual is the origin of its namesake golden sheen. It is widely reported in aquarium literature that the intense metallic gold iridescence seen on wild-caught specimens is not the fish’s natural pigmentation at all. Instead, the colouration is commonly attributed to a response to a skin-encysting organism, variously described as a trematode parasite or a fungal infection depending on the source. The precise organism responsible is not universally agreed upon in published accounts, and some sources describe the mechanism slightly differently from others. What is broadly consistent across the literature is that the fish’s immune response to this infection causes guanine crystals to deposit beneath the skin, producing the characteristic golden metallic lustre. Captive-bred stock, raised in parasite-free conditions, typically displays a considerably more muted, silvery or pale gold appearance, which can come as a surprise to hobbyists expecting the vivid wild-caught look.

This quirk aside, the Gold Tetra is a genuinely hardy and straightforward aquarium fish. It is tolerant of a reasonable range of water parameters, adapts readily to commercially available foods, and behaves peacefully in community settings. Its modest adult size, typically around 4 – 4.5 cm (1.6 – 1.8 inches), makes it suitable for modestly sized aquariums, and it thrives when kept in a proper shoal. For UK fishkeepers looking for a characterful, low-maintenance tetra with an interesting story behind it, the Gold Tetra is well worth considering.

Appearance

In profile, the Gold Tetra has the typical compressed, diamond-shaped body plan shared by many small Hemigrammus species. The body is relatively deep for its length, with a slightly rounded belly and a forked, translucent caudal fin. Adult specimens typically reach around 4 – 4.5 cm (1.6 – 1.8 inches) in standard length, making them one of the smaller, more manageable tetras available in the UK trade.

The defining visual feature is the golden iridescence that gives the fish its common name. In wild-caught specimens, this can be remarkably intense, covering much of the flanks and gill covers with a bright, almost brassy metallic sheen. As discussed in the introduction, this colouration is widely attributed in aquarium literature to guanine crystal deposits triggered by a skin-encysting organism rather than being the species’ inherent pigmentation. The precise nature of the organism responsible varies between sources, with some citing a trematode (digenean) parasite and others pointing to a fungal infection, so it is best understood as a widely reported claim rather than a single settled mechanism. The fish themselves appear to suffer no obvious ill effects from the condition, and wild populations with this sheen are evidently healthy and reproducing normally.

Captive-bred Gold Tetras, raised in environments free of the relevant parasites or fungi, typically display a much more subdued colouration. They tend to appear silvery to pale gold, sometimes with a faint yellowish wash along the flanks. While still attractive, they lack the mirror-like metallic intensity of their wild-caught counterparts. This is worth bearing in mind when purchasing, as the fish available in many UK shops are increasingly captive-bred.

Other notable markings include a small, dark spot at the base of the caudal fin, which is a useful identification feature shared with several related Hemigrammus species. There may also be a faint reddish or orange tinge to the upper portion of the eye. The fins are generally transparent to slightly yellowish, and the adipose fin, characteristic of the family, is present. Sexual dimorphism is subtle: mature females tend to be slightly deeper bodied and plumper when viewed from above, particularly when carrying eggs, while males are generally slimmer and may show marginally more intense colouration, though these differences can be difficult to discern outside of breeding condition.

Natural habitat

Hemigrammus rodwayi is found across the coastal drainages of the Guiana Shield region, with established populations in Guyana, Suriname, and French Guiana. Some records also place it in tributaries associated with the lower Amazon basin in Brazil, though the Guianan populations are the most frequently cited in the literature. The species inhabits slow-moving to still waters, including creeks, swamps, floodplain pools, and the margins of larger rivers.

These habitats are typically characterised by soft, acidic to neutral water, often stained dark brown with tannins from decomposing leaf litter and other organic matter. The substrate is usually composed of sand, mud, or a thick layer of fallen leaves. Dense marginal vegetation, submerged roots, and overhanging riparian plants provide cover and contribute to the shaded, dimly lit conditions these fish experience in nature. Water temperatures in these lowland tropical environments generally sit within the range of 24 – 28 °C (75 – 82 °F), though seasonal and localised variation certainly occurs.

In these blackwater and clearwater habitats, the Gold Tetra lives alongside a diverse community of other small characins, cichlids, catfish, and invertebrates. The tannin-rich waters with abundant leaf litter likely play a role in the prevalence of the skin-encysting organisms that produce the species’ famous golden sheen, as these environments support complex parasite and fungal life cycles involving various intermediate hosts.

Tank size and setup

A group of Gold Tetras can be comfortably housed in a tank of 60 litres (approximately 13 UK gallons) or more, though larger volumes of 80 – 100 litres (18 – 22 UK gallons) and upwards are always preferable, particularly if keeping them as part of a broader community. The tank should ideally be longer rather than tall, providing horizontal swimming space, as Gold Tetras, like most shoaling tetras, spend much of their time actively moving through the mid-water column.

The aquascape should offer a good balance between open swimming areas and planted or decorated retreats. Dense planting along the sides and back of the tank, combined with an open central swimming space, works very well. Suitable plants include Cryptocoryne species, Java Fern (Microsorum pteropus), Amazon Sword (Echinodorus species), and floating plants such as Amazon Frogbit (Limnobium laevigatum) or Water Lettuce (Pistia stratiotes). Floating plants are particularly useful as they diffuse overhead light and help create the subdued conditions that bring out the best colour and most natural behaviour in this species.

A dark substrate, whether fine sand or a dark-coloured gravel, will show off the fish’s golden tones to their best advantage and also more closely replicates the natural environment. The addition of driftwood, bogwood, and dried leaf litter (Indian Almond leaves or Oak leaves) can further enhance the setup, lowering pH slightly through tannin release and providing a naturalistic aesthetic. If you wish to create a biotope-style Guianan setup, a generous layer of leaf litter over a sandy substrate, combined with tangled root structures and dim lighting, would be ideal.

Standard aquarium lighting is perfectly adequate. Gold Tetras do not require intense light and, if anything, appear more confident and display better colouration under moderate to low light levels. A secure lid or cover glass is recommended, as small tetras can be jumpers when startled.

Water parameters

The Gold Tetra is adaptable and tolerant across a reasonable range of water chemistry, which contributes to its reputation as one of the hardier tetras available. That said, it originates from soft, acidic waters, and maintaining conditions at least loosely reflective of this will promote the best health and colouration.

In much of the UK, tap water tends to be moderately hard and slightly alkaline, which sits towards the upper end of this species’ tolerance. Gold Tetras will generally adapt to these conditions without problems, though keepers in particularly hard water areas may wish to consider blending tap water with RO (reverse osmosis) water to bring the hardness and pH down somewhat. For a standard community setup, however, most UK tap water, appropriately dechlorinated and well maintained, will be perfectly adequate.

Stability is more important than hitting a specific number. Sudden swings in pH or temperature are far more stressful to small tetras than keeping them at a slightly higher or lower value consistently. Weekly water changes of 20 – 30% are recommended to keep nitrate levels in check and maintain overall water quality. If you are keeping the fish in a heavily planted or blackwater-style setup with tannin-stained water, be aware that pH can drift downward over time, and monitor accordingly.

Filtration and equipment

Gold Tetras do not require powerful filtration and, in fact, prefer a gentle to moderate flow rate that mirrors the sluggish waters of their natural habitat. A standard internal filter, hang-on-back filter, or small external canister filter rated for the tank volume will work well. If using a filter with a strong output, consider diffusing or redirecting the flow with a spray bar or lily pipe to avoid creating excessive current. Small tetras can become stressed and exhausted if constantly fighting a strong flow.

A reliable aquarium heater is essential for maintaining tropical temperatures in a UK home. A heater rated appropriately for the tank volume, typically around 1 watt per litre as a rough guide, should be sufficient. Use a separate aquarium thermometer to verify the heater’s accuracy, as built-in thermostats can occasionally drift. Position the heater near the filter outlet to help distribute warmed water evenly throughout the tank.

An air pump is not strictly necessary if the filter provides adequate surface agitation for gas exchange, but one can be useful in warmer weather when dissolved oxygen levels may drop. If running a heavily planted or blackwater setup with reduced surface movement, an airstone on a low setting can provide a useful safety margin.

Lighting can be whatever suits the plants in the aquarium. Gold Tetras themselves have no special lighting requirements and will show their best colour under moderate illumination. If using high-intensity plant lighting, floating plants or surface shade will help keep the fish comfortable.

Diet and feeding

The Gold Tetra is an undemanding omnivore that accepts a wide variety of aquarium foods without fuss. In the wild, its diet consists of small invertebrates, insect larvae, worms, and plant matter, and it readily transitions to prepared foods in captivity.

A high-quality micro-pellet or flake food formulated for small tropical fish should form the staple diet. Look for products with good protein content from whole fish or insect meal, and avoid those bulked out primarily with fillers. Supplement this staple with regular offerings of frozen or live foods such as daphnia, baby brine shrimp (Artemia nauplii), cyclops, bloodworm, and mosquito larvae. These not only provide excellent nutrition but also encourage natural foraging behaviour and help bring out the best condition and colouration in the fish.

Feed small amounts once or twice daily, offering only what the shoal can consume within two to three minutes. Gold Tetras are mid-water feeders and will readily take food as it drifts through the water column. They are not typically shy at feeding time once settled, though newly introduced fish may take a day or two to begin feeding confidently. Avoid overfeeding, as uneaten food will degrade water quality, particularly in smaller aquariums.

Variety is the key to good nutrition with this species. A rotation of two or three different dry foods alongside regular frozen or live treats will ensure all nutritional needs are met and keep the fish in robust health.

Behaviour and temperament

Gold Tetras are peaceful, active shoaling fish that spend the majority of their time swimming together in the mid-water column. They are not aggressive towards other species and pose no threat to plants, invertebrates, or similarly sized tank mates. Within the shoal, there may be occasional, brief chasing and jostling for position, but this is normal social behaviour and rarely results in any damage.

Like all true shoaling tetras, Hemigrammus rodwayi should be kept in a group of at least six individuals, with eight to ten or more being preferable. In smaller numbers, the fish tend to become shy, stressed, and prone to hiding, which significantly diminishes their appeal and can compromise their health. A larger group allows the natural shoaling dynamic to develop, and a well-sized shoal of Gold Tetras moving through a planted aquarium is a genuinely attractive sight, the golden flanks catching the light as the group turns and drifts together.

They are not especially timid compared to some other small tetras, but they do appreciate cover and subdued lighting. In a bare, brightly lit tank, they may appear washed out and nervous. Providing planted areas, driftwood, and floating plants gives them the security to swim confidently in the open. They are generally active during the day and settle into quieter resting positions among plants or near the substrate at night.

Gold Tetras are compatible with a very broad range of community fish provided those tank mates are not large enough to eat them or aggressive enough to harass them. Their peaceful nature and modest size make them ideal residents for a well-stocked, thoughtfully planned community aquarium.

Tank mates

The Gold Tetra’s peaceful temperament and small size make it compatible with a wide range of similarly natured community fish. Ideal companions are other small, non-aggressive species that share similar water parameter preferences. Avoid housing Gold Tetras with anything large enough to view them as food, or with boisterous, fin-nipping species that could cause stress.

Good tank mates

• Cardinal Tetra, a classic companion sharing similar soft-water preferences and a peaceful disposition
• Rummy Nose Tetra, another tight-shoaling species that thrives in the same conditions
• Ember Tetra, a tiny, colourful tetra that adds visual contrast without any aggression
• Corydoras sterbai, a peaceful bottom-dwelling catfish that occupies a different zone of the tank
• Kuhli Loach, a gentle, quirky bottom dweller well suited to soft-water community setups
• Harlequin Rasbora, a similarly sized and tempered shoaling species
• Honey Gourami, a calm, small labyrinth fish that makes an excellent centrepiece companion
• Otocinclus, a small algae-eating catfish that is entirely peaceful and keeps to the glass and plant surfaces
• Cherry Shrimp, a popular invertebrate that coexists well with Gold Tetras, though some very small shrimplets may occasionally be taken
• Apistogramma cacatuoides, a dwarf cichlid that pairs well with small tetras in a suitably sized and decorated tank

Fish to avoid

• Oscar, far too large and predatory to house with any small tetra
• Jaguar Cichlid, a large, aggressive predator that would quickly consume Gold Tetras
• Tiger Barb, a notorious fin nipper that can cause stress and physical damage, especially in smaller groups
• Red Tail Catfish, a monster-growing catfish completely unsuitable for community life with small fish
• Convict Cichlid, territorial and aggressive, particularly when breeding
• Green Terror, a large, boisterous cichlid that would dominate and endanger small tetras
• Flowerhorn, a large, highly aggressive hybrid cichlid entirely incompatible with small community fish
• African Butterfly Fish, a surface-dwelling predator with a mouth large enough to swallow small tetras
• Bucktooth Tetra, despite being a tetra itself, this species is a scale-eating predator unsuitable for community tanks
• Jack Dempsey, a large, territorial cichlid that would pose a serious threat to small tank mates

Breeding

Breeding Hemigrammus rodwayi in the home aquarium is achievable but requires some preparation, as with most egg-scattering characins. The species is an egg scatterer that shows no parental care, and the adults will readily consume their own eggs and fry if given the opportunity.

To condition a breeding pair or small group, separate males and females (if you can distinguish them, females being fuller-bodied when gravid) and feed generously on high-quality live or frozen foods such as daphnia, baby brine shrimp, and bloodworm for one to two weeks before attempting to spawn them.

A dedicated breeding tank is strongly recommended. A small tank of around 20 – 30 litres is sufficient, filled with soft, slightly acidic water with a pH of around 5.5 – 6.5 and a temperature at the upper end of their range, approximately 26 – 28 °C (79 – 82 °F). Very soft water, ideally 2 – 4 dGH, is often cited as being important for successful egg development. The tank should be dimly lit, as the eggs of many Hemigrammus species are sensitive to light. Fine-leaved plants such as Java Moss (Taxiphyllum barbieri) or spawning mops provide a suitable substrate for the eggs to fall into, and a mesh or grid placed above the base of the tank can help prevent the adults from reaching the eggs after spawning.

Spawning typically takes place in the early morning. The pair engages in a brief courtship display, after which the female scatters adhesive or semi-adhesive eggs among the vegetation or spawning medium. The number of eggs produced can vary; documented accounts for closely related Hemigrammus species suggest several dozen to a few hundred eggs may be produced in a single spawning event, though specific fry counts for H. rodwayi are not always reported in detail in the available literature.

After spawning, the adults should be removed immediately to prevent egg predation. The eggs typically hatch within 24 – 36 hours at tropical temperatures, and the fry become free-swimming a few days later once the yolk sac is absorbed. Initial food should be very small: infusoria, commercially available liquid fry food, or Paramecium cultures, graduating to newly hatched brine shrimp (Artemia nauplii) as the fry grow large enough to take them. Keep the breeding tank dimly lit and maintain excellent water quality with very gentle filtration, such as an air-driven sponge filter, to avoid sucking up the tiny fry.

It is worth noting that captive-bred fry raised in clean aquarium conditions will not develop the intense golden colouration associated with wild-caught fish, as this sheen is widely attributed to exposure to skin-encysting organisms found in their natural habitat rather than to inherent pigmentation.

Common diseases and health

The Gold Tetra is a robust species that is not especially prone to disease when kept in clean, stable conditions. The most common health issues are those shared by virtually all small tropical freshwater fish: ich (white spot disease), caused by the protozoan Ichthyophthirius multifiliis, and various bacterial or fungal infections that tend to emerge when water quality deteriorates or the fish are stressed. Ich presents as small white spots on the fins and body and is readily treatable with widely available aquarium medications and a gradual increase in temperature. Maintaining good water quality through regular water changes and avoiding overstocking are the most effective preventative measures against the majority of common ailments.

The Gold Tetra’s association with skin-encysting organisms in the wild is an unusual aspect of its biology, but this should not cause alarm to aquarists. Wild-caught fish that display the intense golden sheen are not generally observed to be unwell or compromised by the condition. In captivity, these organisms do not appear to spread to other fish species in the aquarium, and captive-bred stock will typically not carry them at all. If purchasing wild-caught specimens, the golden colouration can actually be viewed as an indicator of wild origin rather than a sign of disease. There is no documented evidence that the condition causes significant health problems or reduces lifespan in aquarium settings.

As with all small characins, Gold Tetras can be sensitive to sudden changes in water chemistry, particularly large swings in pH or temperature. Acclimatise new arrivals carefully using a drip acclimatisation method or by gradually mixing tank water into their transport bag over a period of 30 – 60 minutes. Quarantining new fish in a separate tank for two to four weeks before introducing them to an established community is always sound practice and helps prevent the introduction of pathogens to a healthy system. A varied, high-quality diet and a stress-free environment with adequate shoal size and appropriate cover will go a long way towards keeping Gold Tetras in excellent health throughout their lifespan of three to five years.

Frequently asked questions

Why do wild-caught Gold Tetras look more golden than captive-bred ones?

The intense metallic gold sheen of wild-caught Hemigrammus rodwayi is widely attributed in aquarium literature to a skin-encysting organism, variously described as a trematode parasite or a fungal infection depending on the source. The fish’s immune response to this organism causes guanine crystals to deposit beneath the skin, producing the bright golden appearance. Captive-bred fish, raised in clean conditions without exposure to these organisms, tend to display a more muted, silvery or pale gold colouration. This is not a deficiency in the captive-bred fish; it simply reflects the absence of the condition that produces the metallic sheen.

How many Gold Tetras should I keep together?

A minimum of six is recommended, but eight to ten or more is preferable. In larger groups, the fish feel more secure, shoal more naturally, and display better colouration and more interesting social behaviour. Keeping fewer than six often results in shy, stressed fish that spend most of their time hiding.

Are Gold Tetras suitable for beginners?

Yes. The Gold Tetra is one of the hardier small tetras available and adapts well to a range of water conditions. It is peaceful, easy to feed, and tolerant of the minor fluctuations that can occur in a newer aquarium, provided the tank has been properly cycled before the fish are added.

Can Gold Tetras live in hard water?

Gold Tetras are adaptable and will generally do well in moderately hard water, which covers much of the UK’s tap water supply. They originate from soft, acidic waters, so very hard or alkaline conditions are not ideal for long-term health or breeding. For general community keeping, most UK tap water, properly dechlorinated, is acceptable.

Will Gold Tetras eat shrimp?

Adult Gold Tetras are generally safe with adult dwarf shrimp such as Cherry Shrimp. However, very small shrimplets may occasionally be eaten, as with most small fish. If breeding shrimp in the same tank, dense plant cover will help shrimplets survive by providing hiding places.

What is the difference between Gold Tetras and Brass Tetras?

“Brass Tetra” is sometimes used as an alternative common name for Hemigrammus rodwayi, though it can also be applied to other species in the trade. If purchasing fish labelled as Brass Tetras, check the scientific name to confirm the species. Genuine H. rodwayi should display the characteristic dark spot at the base of the caudal fin.

Do Gold Tetras need a heater?

Yes. Gold Tetras are tropical fish requiring a water temperature of 24 – 28 °C (75 – 82 °F). UK room temperatures, particularly during autumn and winter, will not reliably maintain these temperatures, so a thermostatically controlled aquarium heater is essential.

How long do Gold Tetras live?

In well-maintained aquarium conditions, Gold Tetras typically live for three to five years. Good water quality, a varied diet, and a stress-free environment with an appropriate shoal size will help them reach the upper end of this range.

Related guides

• Cardinal Tetra care guide
• Neon Tetra care guide
• Rummy Nose Tetra care guide
• Ember Tetra care guide
• Black Neon Tetra care guide
• Glowlight Tetra care guide
• Lemon Tetra care guide
• Head and Tail Light Tetra care guide