Flag Acara (Laetacara curviceps)

Choose a small South American cichlid with clear care limits

Flag Acara (Laetacara curviceps) is a freshwater cichlid for keepers with a mature filtered aquarium who can measure the water and assess a pair or community carefully. FishBase places it in the Amazon River basin, including lower portions of Amazon tributaries in Brazil, and records a maximum length of 4.6 cm standard length. It is benthopelagic, so plan usable space around the lower aquarium rather than treating it solely as an open-water fish.

Seriously Fish gives the species aquarium range as 20–28°C, pH 4.5–7.5 and 1–15 dGH. Use stable measured values within those ranges and confirm that every intended companion can share the same conditions.

Flag Acara is also known as Smiling Acara, Sheepshead Acara and Blunt-headed Cichlid. The scientific name matters when comparing care because similar common names can be applied to more than one cichlid. This animal belongs to the family Cichlidae.

Decide whether the aquarium is suitable

We rate the care level as intermediate because the aquarium must be biologically mature, water values must be measured, and any pair or community plan needs active observation. A broad water range does not remove the need for stability or compatible companions.

Before choosing this fish, write down the aquarium volume, current temperature, pH, hardness, ammonia and nitrite, then compare the full set with the intended social plan. A measured temperature within range cannot compensate for detectable ammonia, and sufficient litres do not make conflicting water requirements suitable.

Select the dispatch size and understand the sold unit

One purchase supplies one Flag Acara in the size selected. The live size selector lists 3–4 cm, 4–5 cm and > 7 cm dispatch sizes. The size you select is the size supplied, not the adult size.

Dispatch measurements and scientific adult-length figures serve different purposes. The selector describes the animal sent, while the adult reference helps you plan its permanent aquarium. Do not choose an aquarium from the dispatch measurement alone.

Sex is guaranteed only when the selected option explicitly states male or female. This Flag Acara listing has no sex-guaranteed option.

Ordering two fish therefore means receiving two individual animals, not a promised male-and-female pair. Prepare enough filtered aquarium capacity and watch whether each animal can feed, move and rest normally.

The gallery images are representative, based on reference photographs of this species, so colours can look slightly different from the live animal.

Check these points before selecting

• Sold unit: each purchase represents one animal.
• Dispatch size: choose 3–4 cm, 4–5 cm or > 7 cm through the live selector.
• Adult planning: use the 4.6 cm standard-length maximum rather than assuming the dispatch measurement is the final size.
• Social plan: decide whether the aquarium is intended for one animal or a carefully monitored pair before ordering more than one.
• Water: measure temperature, pH and hardness rather than judging suitability by the aquarium’s appearance.

Selecting one means preparing for one individual animal. Selecting two means preparing filtration and usable space for two individuals while retaining a plan for intervention if they do not use the aquarium comfortably together. The dispatch size changes the measurement of the animal sent, but it does not alter its long-term care needs.

Plan the aquarium around the adult size

Start with adult length, social use and filtration capacity rather than the size seen at dispatch. Flag Acara has a maximum FishBase figure of 4.6 cm standard length, while the aquarium profile uses 50 mm standard length. Small body size does not make an immature or crowded aquarium suitable.

OATA’s American-cichlid sheet gives at least 120 litres for a pair of smaller species under 15 cm. This is group guidance for American cichlids, while FishBase records aquarium keeping in pairs and a minimum aquarium size of 60 cm for this species. Use the 120-litre figure as a conservative pair benchmark, then consider the space occupied by substrate, cover, equipment and every other fish.

A single-fish plan avoids assuming that two selected animals will form a suitable pair. A pair plan requires close observation of access to food and space as well as an aquarium meeting the smaller-cichlid benchmark.

Turn the space figures into a stocking decision

Litres are only one part of the decision. A nominal volume can lose usable capacity to décor and substrate, while existing livestock already places demand on the biological filter. Do not rely on this cichlid’s modest recorded length as permission to add another fish.

For example, a 120-litre aquarium intended for two animals should still be rejected if its filter is immature or its lower area is already crowded. An established aquarium meeting the benchmark still needs measured water that suits the fish. Pass all three checks—space, filtration and water—before treating the litre figure as useful.

Match the water range before introduction

Keep the aquarium at 20–28°C, pH 4.5–7.5 and 1–15 dGH. Seriously Fish gives these species aquarium ranges. Treat each value as a permitted range, not a reason to move the aquarium repeatedly between its extremes.

FishBase separately lists environmental values of 22–26°C, pH 5.2–7.5 and 5–12 dH. A community at 24°C, pH 7.0 and 8 dGH is a worked example that sits inside both sets of figures; it is not a required target for every aquarium.

Use each measurement to make a decision

Use our water chemistry guide to understand the measurements, then enter actual test results into the water matcher. A heater setting or local-water average is not a substitute for testing the aquarium itself.

If one value fits but another falls outside the range, resolve the mismatch before adding the fish. The same applies when a proposed companion needs a conflicting temperature, pH or hardness. Choosing livestock that already suits the measured water is more dependable than repeatedly altering chemistry after stocking.

Record actual numbers rather than writing only that the water is “soft” or “warm”. If a later test changes sharply, investigate the cause before adding livestock instead of making several adjustments at once.

Mature and protect the biological filter

A working biological filter is essential. RSPCA aquarium welfare guidance explains that fish release toxic ammonia, which filter bacteria convert first to toxic nitrite and then to safer nitrate. A powered filter alone is not enough; the bacterial population must be established and maintained.

Prepare the system through our first tropical tank guide before livestock arrives. Test ammonia and nitrite until both are 0 mg per litre. Add fish slowly because increased feeding and waste require the bacterial population to grow with the new load.

Read test results as actions

• Ammonia above 0 mg per litre: treat the aquarium as biologically unsafe and stop increasing its livestock load.
• Nitrite above 0 mg per litre: respond in the same way; nitrite is toxic even though the first conversion stage is operating.
• Rising nitrate: review feeding, stocking and the weekly partial-water-change routine.
• Reduced filter flow: check for blockages without washing the biological media under tap water.
• New fish added recently: test more closely because the filter is adapting to greater waste production.

New tank syndrome occurs when there are too few nitrifying bacteria to process the waste created by the fish. The result can be unhealthy ammonia and nitrite levels, illness and death. Prevent it by maturing the filter first, confirming zero readings and increasing livestock numbers gradually.

Do not replace all biological media during routine cleaning. When cleaning is required, rinse it lightly in aquarium water removed during a partial water change. This protects more of the bacterial population from chlorine or chloramine and restores flow without treating mature media as disposable.

Test before every stocking increase, then continue watching ammonia, nitrite, nitrate and filter flow as feeding and waste rise. If ammonia or nitrite appears, pause further additions and restore safe water quality.

Build cover around usable lower space

FishBase describes Flag Acara as benthopelagic, so include the lower aquarium when judging whether the layout works. Substrate, décor and cover should leave the fish room to move and feed rather than turning the entire lower area into an obstacle course.

American-cichlid guidance recommends fine aquarium gravel or sand because many members of the group dig or sift substrate while feeding or breeding. Use one of those substrate types and keep it clean through the weekly siphoning routine. Make sure the filter can circulate and process waste without the intake remaining blocked.

Cover is useful, but live planting needs a practical plan. American cichlids may dig up or eat live plants, so do not depend on delicate planting as the only structure in the aquarium. Plastic aquarium plants can provide alternative cover where rooted plants are repeatedly disturbed.

Balance cover and access

Judge a layout by function rather than by a particular visual style. The essential outcomes are accessible space, cover, a substrate appropriate for the cichlid group and a filter that continues to operate correctly. If décor prevents observation or traps uneaten food, simplify the arrangement until maintenance and daily checks are straightforward.

Before introduction, confirm that you can see the fish during daily checks, inspect the filter intake, reach the substrate with a siphon and place food where the animal can find it.

Feed variety in one measured daily meal

Wild Flag Acaras are probably foragers that take algae, organic detritus, small insects, worms, crustaceans and other zooplankton. In the aquarium, use good-quality dried flakes or granules alongside appropriately small live, frozen or freeze-dried foods. At least some of the dried food should include plant or algal content.

Bloodworm, Daphnia and Artemia are named options for variety. Rotate them with the prepared staple rather than building the diet around one item. Choose particles the fish can take readily and watch the animal itself eat, especially when other residents reach the food first.

The daily schedule comes from OATA’s American-cichlid guidance: feed once a day and give only what the fish can eat within a few minutes. This keeps the portion visible and limits uneaten food. Large servings can create excess faeces or leave food to break down, releasing toxic waste into the water.

Give each food a clear role

If food remains after the feeding window, reduce the next portion and remove the excess during maintenance. If the Flag Acara shows reduced interest while other fish continue eating, check water quality and whether it has fair access to the meal.

The useful portion is the amount the fish can take within a few minutes without leaving food to decay. If another resident consumes the prepared food first, change how the portion is distributed while keeping the same daily limit.

Use a repeatable weekly maintenance routine

Change 25% of the aquarium water at least once every week. Use a siphon to remove solid waste from the substrate, and treat replacement tap water with conditioner to remove chlorine or chloramine before it enters the aquarium.

Test the water at least weekly for ammonia and nitrite, with both remaining at 0 mg per litre. Monitor nitrate against the limit of no more than 20 mg per litre above the normal tap-water level. Keep a simple written result so gradual changes are easier to see than they are from memory.

Follow the same order each week

1. Observe swimming, breathing, colour, temperament, body condition and appetite before disturbing the aquarium.
2. Test ammonia, nitrite and nitrate, then compare the result with the previous week.
3. Remove 25% of the water while siphoning solid waste from the substrate.
4. Check the filter for blockages and reduced flow.
5. If media needs cleaning, rinse it lightly in the aquarium water just removed.
6. Treat the replacement water with conditioner before adding it to the aquarium.
7. Recheck the fish after maintenance for normal swimming and breathing.

Never run established biological media under the tap. Chlorine or chloramine may kill part of the bacterial population that processes fish waste. Cleaning in removed aquarium water protects the filter while allowing you to clear material that is restricting flow.

Use the first month to establish a baseline. During week one, concentrate on water readings, appetite and breathing. By the end of the first month, compare body condition, behaviour and nitrate trends with the first observations. If the aquarium needs larger corrective work every week, review feeding, stocking and filter performance.

A useful record contains the date, test results, water-change percentage, filter-flow observation and any change in feeding or behaviour.

Prepare for arrival and watch health changes

Prepare the mature aquarium before the fish arrives. Confirm that ammonia and nitrite are 0 mg per litre and that temperature, pH and hardness are within the chosen species ranges. Read the current delivery and Live Arrival Guarantee policy and arrange for someone to be present to receive the parcel.

Follow the arrival sequence

1. Start filming before the sealed parcel is opened, keeping the outer box visible.
2. Open the parcel in one continuous take and show the fish while it is still inside the sealed bag.
3. Inspect the parcel on the day it arrives and keep the video through release.
4. Float the bag for 20–30 minutes before releasing the fish.
5. Never pour the bag water into the aquarium.

Increase fish numbers slowly after the filter has matured. Every addition increases waste and feeding, so the bacterial population must adjust to the new load. Avoid combining the arrival with several other livestock additions when that would make changes in water or behaviour difficult to interpret.

Use visible changes as prompts

During the first week, check swimming position, breathing, access to cover, response to food and interaction with other fish at a consistent time each day. If a health change persists, test the water and contact us for further guidance.

Screen every community plan individually

Mixing American cichlids can be difficult because members of the group vary greatly in adult size and temperament. OATA says some calmer American cichlids can take part in a robust community with larger shoaling fish, while more aggressive members may need to live alone or with equally aggressive cichlids. That broad pattern is not a fixed tank-mate list for Flag Acara.

Assess the proposed combination through measured water, adult size, use of the aquarium and the total biological load. Individual temperament and breeding status can change the result, so judge the exact stocking plan rather than relying on a permanent “community fish” label.

Apply five compatibility screens

If one screen fails, treat the combination as unsuitable until the conflict is resolved. Matching temperature while ignoring aggression is not enough, and a large aquarium does not correct incompatible water requirements.

Run the screens in order. First compare measured water, then calculate space using adult planning sizes, consider where each fish feeds and rests, and review existing behaviour and recent filter results. A plan that fails one screen remains a poor choice until that conflict has been removed.

Browse our South American cichlid collection to compare identities and adult planning information, but do not assume shared geography means two fish belong together. For an assessment of your aquarium, contact us with its volume, measured water values, filter status and complete livestock list.

Choose between one animal and a carefully observed pair plan

FishBase records aquarium keeping in pairs for Flag Acara. Begin with a defined social plan rather than adding several animals and deciding what to do only after pressure appears.

A one-animal plan still needs adult space, compatible water and a mature filter. A two-animal plan uses OATA’s benchmark of at least 120 litres for a pair of smaller American cichlids and requires separate observation of both animals. Two purchases mean two fish, but the sold unit does not create a compatible pair.

Seriously Fish identifies Laetacara curviceps as a biparental substrate-spawner. If two animals form a breeding pair, continue checking whether every resident can use the aquarium and reach food instead of assuming that an arrangement remains suitable indefinitely.

Act on early warning signs

• One fish hides more than normal: check whether another animal is controlling its access to space.
• Aggression increases: reassess the pair and community plan before fin or scale loss develops.
• One animal stops feeding: confirm food access and test ammonia and nitrite.
• Fins or scales become damaged: stop treating the social arrangement as successful and protect the affected animal.
• Breathing changes: test the water first, because social stress and water-quality problems can occur together.

Keep alternative mature accommodation in mind when choosing more than one cichlid. Décor changes may alter how fish use the aquarium, but observation remains the deciding test. A suitable arrangement lets every fish feed, swim and rest without persistent aggression or exclusion.

Compare both animals separately during the first month. Record whether each one reaches the daily meal, uses more than one part of the aquarium and maintains intact fins and scales. Repeated hiding or exclusion is a reason to reassess the arrangement even when open fighting is not visible.

Answer the key Flag Acara questions

How big does a Flag Acara get?

FishBase records a maximum length of 4.6 cm standard length for Flag Acara. Plan the permanent aquarium around that adult figure rather than the dispatch size.

What size aquarium does a Flag Acara need?

FishBase records a minimum aquarium size of 60 cm. For a pair, OATA’s American-cichlid group guidance gives at least 120 litres for smaller species under 15 cm; account for décor, other livestock and usable lower space.

How many Flag Acaras should I keep together?

FishBase records aquarium keeping in pairs. Two fish are not guaranteed to form a compatible pair, so monitor each animal’s access to food and space and keep alternative mature accommodation in mind.

Is Laetacara curviceps suitable for beginners?

We rate it as intermediate because it needs a mature filtered aquarium, measured water and active observation of any pair or community plan. Ammonia and nitrite must remain at 0 mg per litre.

What does a Flag Acara eat?

Feed good-quality flakes or granules, including some plant or algal content, with bloodworm, Daphnia and Artemia for variety. OATA’s American-cichlid guidance says to feed once daily only what it can eat within a few minutes.

What temperature and pH does this fish need?

Seriously Fish gives an aquarium range of 20–28°C, pH 4.5–7.5 and 1–15 dGH. Keep the chosen values stable and make sure every companion shares them.

Is it aggressive or does it nip fins?

Its individual temperament must be observed rather than assumed. Reassess the arrangement if you see persistent aggression, hiding, feeding exclusion, damaged fins or lost scales.

Which kinds of animals can it live with?

Use only individually assessed companions that share its water requirements and fit the aquarium’s adult-size, temperament, space and filtration limits. OATA notes that American-cichlid mixes can be difficult, so no companion type should be treated as universally suitable.

How does this fish arrive alive?

Someone must be present to receive it. Film every delivery continuously from the sealed parcel as it is opened, with the fish still inside the bag; then float the bag for 20–30 minutes before release and never pour the bag water into the aquarium.

Consult the care references

• FishBase: scientific identity, family, South American distribution, freshwater environment, environmental values, aquarium keeping and maximum standard length.
• Seriously Fish: species aquarium water ranges, diet and biparental substrate-spawning classification.
• Ornamental Aquatic Trade Association: American-cichlid guidance for space, water quality, feeding, introduction, maintenance and compatibility.
• RSPCA: general aquarium welfare guidance covering biological filtration and the conversion of ammonia through nitrite to nitrate.