Gold Flash Cichlid (Thorichthys aureus)

Meet the Gold Flash Cichlid, a golden Thorichthys from Central America

The Gold Flash Cichlid (Thorichthys aureus) is a medium-sized Central American cichlid and a close relative of the Firemouth. The Latin name aureus means golden, and adults have warm gold to olive flanks, a round black spot in the middle of the body, an orange-red throat speckled with turquoise, and long fins edged in red. It is a sand-sifter by nature, a fish you watch working through the substrate all day, and a good choice if you like Firemouths but want something less common.

All nine species of Thorichthys listed on Wikipedia stay under 17 cm standard length. They have pointed heads, often a large dark spot or a dark stripe on the body, and they feed mainly on invertebrates and detritus taken from the bottom. Browse our Thorichthys cichlids to compare the genus side by side.

Check the names on the label

Albert Günther described the species in 1862 as Heros aureus, from a single fish collected at Lake Izabal in Guatemala, according to Eschmeyer's Catalog of Fishes. While it sat in Cichlasoma the name became Cichlasoma aureum, which is why "aureum" still appears on labels. Aquarium Glaser records the first imports in 1911, more than 20 years before the Firemouth, yet it never became as popular.

Know exactly what you receive

One purchase supplies one live Gold Flash Cichlid. The size option is "Standard": the fish is sent at the size currently available, which is well below adult size. Sex is not chosen or guaranteed, because young fish are hard to sex.

Expect a young fish to look plainer than the pictures. Aquarium Glaser notes that this species stays pastel coloured until it reaches about 10 cm, while the Firemouth colours up much earlier. The gold body, black flank spot and red throat strengthen as the fish matures, settles and starts to display. The photographs show the type of fish, not the individual you will receive.

Plan a pair or a group

• One fish: a calm centrepiece for a community of robust, medium-sized fish.
• A pair: buy two or more young fish and let a pair form naturally; this is the method Seriously Fish recommends for the related Firemouth.
• A group: possible in a large tank; outside breeding these cichlids live together peacefully, but each pair claims a patch of floor when it spawns.

Check our delivery and Live Arrival Guarantee information before you order, and have the aquarium matured and at temperature before the fish arrives.

Give a 15 cm cichlid enough floor space

FishBase gives a maximum of 15.0 cm standard length (measured from the snout to the base of the tail), and the Fishkeeper profile also gives 15 cm. Males usually grow larger than females. Plan for a deep-bodied fish of that size plus its tail, not for the size that arrives.

No tank size is published for this species. For the closely related Firemouth, which reaches 120 mm standard length, Seriously Fish gives a base of 120 × 30 cm (about 108 litres) for a single pair and says it does better in larger tanks. OATA advises at least 120 litres for a pair of American cichlids under 15 cm and at least 300 litres for species over 15 cm. The Gold Flash sits on that line, so we treat 120 cm as the floor for a young pair and recommend working towards 300 litres for adults or a group.

Run a quick space check

1. Measure the base: 120 cm long or more, with as much front-to-back depth as you can give; these fish use the floor, not the height.
2. Work out the real volume: our stocking calculator shows how much room is left once your other fish are counted.
3. Plan the territories: one patch of open sand with a flat stone for each pair you expect, separated by rocks or wood.

Build a sand-sifter's layout

In the wild this fish lives in warm lakes and lagoons but prefers the lower and middle reaches of rivers, according to FishBase. Thorichthys feed by taking mouthfuls of substrate and sifting out food, then pushing the sand back out through the gills. That makes the floor the most important part of the aquarium.

The Fishkeeper profile recommends fine, soft sand, because sharp sand damages the gills of a fish that sifts all day. Add driftwood and smooth rocks to form caves and shade, and keep open swimming space along the front. Wild waters are often slightly murky with little vegetation, so a dense plant layout is not needed.

Zone the tank by job

Bed every rock directly on the glass before the sand goes in, so sifting cannot undermine it. Seriously Fish adds that ceramic pots and plastic pipe work as well as natural decor, provided there is enough cover for each fish.

Match the water: warm, steady and on the hard side

The published ranges differ a little. FishBase gives 24–28°C, a pH of 7.5 upwards and a hardness of 2–15 dH. The Fishkeeper profile gives 24–30°C, pH 7.0–8.0 and a carbonate hardness of 6–20 degrees. OATA's general figures for American cichlids are 22–27°C and pH 6.5–8.0. We suggest the overlap below, which suits all three.

Match your tap water

Much of southern and eastern England has hard, alkaline tap water that suits this fish once it is treated with a conditioner. Supplies in Scotland, Wales and parts of northern and south-west England are often softer; there, a little crushed coral or limestone in the filter raises pH and hardness gradually. Check your supply on your water company's postcode checker, compare it with our water matcher, and read our water chemistry guide to understand each number.

Filter well and keep nitrate low

A fish that stirs up sand all day sends fine particles into the water, and Seriously Fish stresses that water quality is of the utmost importance for Thorichthys, which should never go into an immature aquarium. Choose a filter rated well above your tank volume, with mechanical media to catch suspended sand and plenty of biological media. Our guide to aquarium filtration explains the choices.

Follow a weekly routine

1. Test ammonia, nitrite, nitrate and pH; OATA advises testing at least once a week.
2. Change about 25% of the water with conditioned water at the same temperature.
3. Siphon the surface of the sand where waste settles, without digging deep.
4. Rinse filter sponges in removed tank water, never under the tap.
5. Check the heater against a separate thermometer.

Add fish gradually. OATA explains that the filter bacteria must grow every time stocking and feeding increase, and stocking too fast causes "new tank syndrome".

Feed a measured, varied meal

Wild Thorichthys eat small crustaceans, other invertebrates, molluscs and detritus sifted from the bottom, as Seriously Fish describes for the Firemouth. In the aquarium the Gold Flash is an omnivore. The Fishkeeper profile recommends flake, granules, cichlid pellets and frozen foods, kept varied, and suggests small sinking pellets so that food reaches the sand where the fish naturally feeds.

Build one measured meal

• Staple: a small sinking cichlid pellet or granule with a vegetable content such as Spirulina.
• Meaty food: frozen bloodworm, brine shrimp or mysis two or three times a week.
• Portion: only what is eaten within a few minutes, once a day, as OATA advises for American cichlids, which can eat large amounts in one sitting.
• Placement: drop food over open sand, away from the cave of a spawning pair, so every fish gets a share.

Watch the belly. A well-fed fish is rounded but not swollen. Overfeeding fouls the sand and raises nitrate, which the Fishkeeper profile links to health problems in this species.

Settle it in during the first week

Only add the fish to a filtered aquarium that has run long enough to process waste, with ammonia and nitrite at zero. OATA describes the floating-bag method: switch off the aquarium lights, float the sealed bag for about 10 minutes to match temperature, add small amounts of tank water over up to 20 minutes, then release the fish with as little bag water as possible. Our guide on how to acclimatise new fish shows each step.

Use first-week checkpoints

Choose calm tank mates and read the gill-flare display

The Fishkeeper profile describes the Gold Flash as shy and peaceful outside breeding. It settles most disputes by bluff, flaring its gill covers, which carry eye-like spots, rather than by fighting. When a pair spawns it becomes territorial and defends its patch firmly. Aquarium Glaser notes that the Firemouth is on average much more aggressive, and calls the Gold Flash a fish for connoisseurs.

Screen each companion

The Fishkeeper profile suggests robust livebearers such as swordtails or goodeids, small to medium Central American characins and rainbowfish, and warns against large, aggressive species. If you like the genus, compare the Firemouth Cichlid and the Ellioti Cichlid, and read our Firemouth cichlid guide, much of which applies here. Check any mix with our tank mates tool and browse all South and Central American cichlids or the wider American cichlid category.

Watch these health signs

OATA describes a healthy fish as having clear, bright eyes, undamaged fins, intact scales, no ulcers or lumps, normal swimming and steady breathing. Signs of trouble include clamped fins, flicking against decor and shimmying. Learn what normal looks like for your fish in the first month, including where it sifts and how it reacts at feeding time. Our cichlid care guide covers the common problems.

Pair each sign with an action

Breed a pair of Gold Flash Cichlids

According to the Fishkeeper profile, females are smaller and rounder and have a dark blotch in the middle of the dorsal fin, which males lack, and both sexes show vertical bars during spawning. Fish mature at about 6–7 cm. A pair cleans a flat rock or piece of slate in a sheltered spot, and the female lays 100–500 eggs in small batches, each fertilised by the male.

Follow the brood timeline

Seriously Fish notes for the Firemouth that young pairs often eat their first broods, and that in a community tank the eggs or the other fish should be moved if you want to raise many fry.

Answer Gold Flash Cichlid buying questions

What is a Gold Flash Cichlid?

It is Thorichthys aureus, a Central American cichlid from the Atlantic slope between Quintana Roo in Mexico and the Motagua basin in Honduras. It is a close relative of the Firemouth and is also sold as the Blue Flash, Aureus or Aureum Cichlid.

Is Thorichthys aureum the same fish?

Yes. "Aureum" is the spelling from the years when the fish was placed in Cichlasoma (Cichlasoma aureum). In Thorichthys the correct form is Thorichthys aureus.

How big does a Gold Flash Cichlid get?

FishBase gives a maximum of 15 cm standard length, measured without the tail, and the Fishkeeper profile also gives 15 cm. Males usually grow larger than females.

What size tank does it need?

For a pair we treat a 120 cm long tank as the minimum, following the 120 × 30 cm base Seriously Fish gives for the slightly smaller Firemouth. OATA advises at least 300 litres for American cichlids over 15 cm, so plan towards that figure for adults or a group.

Does it need hard water?

It does best in medium to hard, alkaline water. FishBase gives pH 7.5 upwards and 2–15 dH; the Fishkeeper profile gives pH 7.0–8.0. We suggest pH 7.5–8.0, 24–27°C and a general hardness of 5–15 dGH.

Is it aggressive?

Not usually. It settles most disputes by flaring its gill covers and is described as shy and peaceful outside breeding, but a spawning pair defends its patch firmly. Aquarium Glaser notes that the Firemouth is on average much more aggressive.

Why is my young fish so pale?

Young Gold Flash Cichlids are pastel coloured until they reach about 10 cm, according to Aquarium Glaser. The red throat and gold flanks develop as the fish grows and settles.

Will it dig up my plants?

It sifts sand all day, so anything rooted in its feeding area may be loosened. Robust plants fixed to wood or rocks, or planted in pots, are the safest choice; the Fishkeeper profile says robust plants are possible.

How many fish come with one purchase?

One live fish of the standard size currently available. Sex is not chosen or guaranteed; young fish are hard to sex.

Consult the care references

• FishBase: Thorichthys aureus — valid name, maximum standard length, temperature, pH and hardness, range, habitat and IUCN status.
• Eschmeyer's Catalog of Fishes: Heros aureus — original name Heros aureus Günther 1862, type locality Lake Izabal and the full Atlantic-slope range.
• Fishkeeper: Aureus Cichlid — adult size, water range, temperament and gill-flare displays, tank mates, sexing and a breeding outline.
• Aquarium Glaser: Thorichthys aureus (2023) — import history since 1911, the pastel colour of young fish and a comparison with the Firemouth.
• Seriously Fish: Thorichthys meeki — genus-level care for Thorichthys: tank base, sand sifting, diet, group life and spawning.
• Wikipedia: Thorichthys — the nine recognised Thorichthys species and the genus size limit.
• OATA: How to look after American cichlids — UK guidance on water quality, tank volume, acclimatisation, feeding and weekly water changes for American cichlids.
• Tropical Fish Co delivery policy — current dispatch days and Live Arrival Guarantee terms.