Red-Chinned Aphyosemion (Aphyosemion calliurum)

Recognise this West African killifish

Red-Chinned Aphyosemion is the trade name used here for Aphyosemion calliurum, a freshwater killifish in the family Nothobranchiidae from coastal rainforest waters of West Africa, from southern Benin and southern Nigeria to south-western Cameroon. FishBase records the Banner lyretail as a freshwater, benthopelagic and non-migratory African rivuline. It records a maximum length of 5 cm total length for a male or unsexed fish, so 5 cm is the decisive size for adult planning. This fish suits a keeper prepared to maintain stable water, biological filtration, a secure cover and numerous sheltered places.

Wikipedia places Aphyosemion calliurum in coastal rainforest waters of West Africa. In the aquarium, the practical priorities come from its small adult size and wider killifish husbandry: stable water, biological filtration, a secure cover and numerous sheltered places.

Who should choose it?

This fish suits a keeper prepared to test water every week, maintain a mature filter and control the pace of stocking. The aquarium should be calm rather than busy, with enough plant or ornament cover for fish to move out of one another’s sight. Those requirements matter more than decorative style: either live plants or suitable artificial plants and ornaments can create the shelter recommended for killifish.

Mixed-community plans need deliberate screening because killifish generally dislike boisterous companions, while OATA advises that community killifish should not be kept with other long-finned species because some males may be aggressive towards them. A quiet, covered aquarium built around the killifish group is the clearest starting point. You can compare the animal with the shop’s current killifish collection, but assess every proposed combination separately rather than assuming that all killifish need identical conditions.

Understand the animal and dispatch size

One purchase supplies one Red-Chinned Aphyosemion. The dispatch size associated with this offer is 3–4 cm; this is the approximate size at dispatch, not a claim that the fish has reached its adult maximum. FishBase records up to 5 cm total length, so use 5 cm when judging space, group capacity and the adult sizes of potential companions.

Do not plan the aquarium around a short-term dispatch measurement: the difference between a 3 cm arrival and a 5 cm planning length affects how much open swimming room and shelter the group can use as the fish grows. Aquarium capacity must also account for the complete fish population, not merely the length of this one animal.

Plan the purchase unit correctly

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

Do not infer sex, maturity or origin from size, colour or a gallery image. Some gallery images are representative, based on reference photographs of this species, and none shows the exact animal supplied, so colours can look slightly different from the live animal.

Prepare the aquarium before arranging its arrival, then read the current delivery and Live Arrival Guarantee policy for receipt and claim terms. The aquarium should already have a working biological filter, suitable test results, a secure cover and enough shelter for the intended group.

Start with the decisive care numbers

OATA’s killifish guidance gives 22–27°C, pH 6.0–7.5 and general hardness of 4–12°dH for the group; these are broad aquarium guidelines rather than a species-specific optimum. It also gives carbonate hardness of 3–10°dKH, ammonia and nitrite at 0 mg/L, and nitrate no more than 20 mg/L above the normal level in the tap water.

FishBase separately records a tropical environmental range of 24–26°C and pH 5.8–7.2 for Aphyosemion calliurum. Use the overlap between the FishBase species range and OATA’s aquarium guidance for routine care: 24–26°C and pH 6.0–7.2. Choose a stable point within those ranges rather than allowing aquarium readings to swing from one end to the other.

Use these values for distinct decisions

OATA recommends at least 40 litres for a small group of the smallest killifish and at least 90 litres for a group of species over 7 cm. Because this animal is recorded to 5 cm, the 40-litre figure is the relevant group-level starting point, not a species-specific minimum. A larger aquarium offers greater environmental stability and more room for shelter, so increase space when the complete stocking plan, group mix or layout needs it.

The same guidance suggests keeping at least three killifish, normally with two females for each male, to reduce stress on females or other inhabitants. Treat that as a group-planning framework. Do not assume a particular sex ratio from an offer that does not explicitly name sex, and do not add fish merely to reach a number if the aquarium cannot support the resulting waste load.

Decide whether the setup fits

Build a covered aquarium with shelter

Start with a filtered aquarium that can accommodate the intended killifish group at adult size. OATA recommends at least 40 litres for a small group of the smallest species and advises choosing as large an aquarium as is reasonable. The extra water volume helps stabilise temperature and water quality, while the larger footprint creates more room for shelter and visual separation.

A cover is essential for a killifish aquarium. Fit it before the fish arrives and check that the aquarium remains properly covered after feeding, testing and maintenance. Equipment openings still need to serve their purpose without leaving the aquarium routinely uncovered.

Give every area a job

• Base: use aquarium gravel or sand.
• Shelter: ideally use plenty of live plants, particularly when more than one male may be present.
• Alternative cover: where live plants are not used, add suitable artificial plants and ornaments such as plant pots or model caves.
• Water processing: install and mature a biological filter before introducing livestock.
• Swimming room: balance cover with enough unobstructed space for fish to move and feed.

Cover is functional rather than merely decorative. It gives shy or pressured fish places to move away from tank mates, which is particularly useful when a group contains competing males or when a new animal is settling among established inhabitants. Spread shelter through the aquarium instead of placing every plant and ornament in one corner. This creates several usable areas rather than a single retreat that one fish might occupy.

Plan the complete stocking load while arranging the layout. A nominal 40-litre aquarium filled heavily with ornaments does not offer 40 litres of open water, and other fish also contribute waste. The OATA figure concerns a small killifish group, so it should not be treated as spare capacity for an unrestricted community.

If this is your first filtered aquarium, follow the shop’s guide to preparing and maturing a first tropical tank before livestock arrives. Maturation is a biological process: the filter needs an established bacterial population capable of processing waste, not simply equipment that has been switched on.

Set water values before introduction

Measure the aquarium rather than judging water by appearance. Clear water can still contain toxic ammonia or nitrite, and temperature, pH and hardness all require appropriate tests or measuring equipment. Record the readings so that gradual movement is visible before it becomes a larger husbandry problem.

For routine care, use 24–26°C and pH 6.0–7.2, the overlap between FishBase’s species range and OATA’s aquarium guidance. Use general hardness of 4–12°dH and carbonate hardness of 3–10°dKH as the broader killifish guidance. Keep ammonia and nitrite at 0 mg/L. Nitrate should not exceed 20 mg/L above the normal concentration in the tap water used for replacement water.

Read each result as an action

The shop’s aquarium water-chemistry guide explains what the principal readings mean, while the water matcher helps compare measured aquarium water with the stated guidance. Enter actual test results rather than estimates so that a compatibility decision reflects the aquarium the fish will enter.

The routine temperature and pH ranges are deliberately limited to the overlap between FishBase’s environmental entry of 24–26°C and pH 5.8–7.2 and OATA’s wider killifish guidance. Stability still matters: do not deliberately move temperature or pH back and forth within a stated band. Establish a suitable point, verify it with tests and maintain it through a consistent routine.

Check the source water as well as the aquarium when interpreting nitrate. The ceiling is expressed relative to the normal tap-water level, so an aquarium reading only makes sense when that baseline is known. Treat every result as part of a pattern alongside feeding, stocking and filter condition.

Mature and protect the biological filter

A filter is essential in this aquarium. RSPCA aquarium guidance explains that fish release toxic ammonia and that a working biological filter supports beneficial bacteria which convert ammonia to nitrite and then to the safer nitrate. The equipment therefore needs both suitable operation and a living bacterial population.

Mature the filter before adding fish. Once livestock is present, increase the aquarium population slowly because the beneficial bacteria need time to respond whenever fish numbers and feeding increase. Adding too many animals too quickly can leave the bacterial population unable to process the additional waste, producing unhealthy ammonia or nitrite.

Protect the bacteria during maintenance

1. Check the filter regularly for blockages or reduced operation.
2. If cleaning is needed, use aquarium water removed during a partial water change.
3. Rinse the filter media lightly rather than cleaning it under the tap.
4. Return the media and restore normal filter operation promptly.
5. Test ammonia and nitrite after any concern about filter performance.

Tap water may contain chlorine or chloramine that can damage the beneficial bacteria in filter media. Using removed aquarium water for a light rinse reduces that risk and avoids stripping away more bacteria than necessary. The purpose is to clear obstructing debris while preserving biological function, not to make established media look unused.

Filtration does not replace water changes, waste removal or controlled feeding. The filter processes dissolved waste, while uneaten food and solid debris still need to be limited or removed. Likewise, a large filter does not justify rapid stocking: bacterial capacity develops in response to the existing waste load and can be overwhelmed by a sudden increase.

Use water tests to judge whether the system is coping. Ammonia and nitrite should remain at 0 mg/L, including after new animals are introduced. If either becomes detectable, pause further additions and review feeding, waste accumulation, filter operation and the maturity of the biological system before expanding the group.

A power supply, running pump or visible water movement alone does not demonstrate biological maturity. The practical signs are stable test results under the aquarium’s real stocking and feeding load, supported by regular maintenance that protects the bacterial colony.

Feed a measured omnivorous diet

Killifish are omnivorous. Use a good-quality flake or granule as the routine aquarium food, choosing a form the fish can take comfortably. Small live or frozen items such as daphnia, brine shrimp or tubifex can also be included for variety.

Feed once a day and give only what the fish can consume within a few minutes. This limit links portion size to the fish’s actual response rather than to a fixed pinch or scoop. Watch the complete group: a portion is too large when food remains after the feeding period, even if some fish ate quickly.

Build the feeding decision in stages

Overfeeding creates two connected problems. Uneaten food breaks down and releases waste into the water, while a larger daily food input also increases the waste produced by the fish. Both effects raise the load on the biological filter and can contribute to deteriorating water quality.

Offer food where the fish can reach it without being crowded by boisterous companions. A mixed aquarium is unsuitable when other inhabitants repeatedly prevent the killifish from feeding, even if the species appear peaceful at other times. Feeding behaviour is therefore one of the practical compatibility checks, not merely a question of appetite.

Live and frozen foods are beneficial additions, but their use does not change the portion rule. Count every food offered as part of that day’s amount and stop when the fish have eaten what they can take within a few minutes. More food is not automatically better variety.

Keep feeding consistent enough to notice a change. Reduced intake or loss of interest is one of the warning signs identified in killifish husbandry guidance. When that happens, look at water readings, breathing, swimming, colour, condition and interactions before deciding that the fish simply prefers a different food.

Make weekly maintenance predictable

Carry out a partial water change of 25% at least once every week. Use a siphon to remove solid waste from the gravel or sand while taking out water, and treat replacement tap water with a suitable conditioner to remove chlorine or chloramine before it enters the aquarium.

The percentage turns into a different volume for each aquarium. A 25% change is 10 litres in a 40-litre aquarium and 22.5 litres in a 90-litre aquarium. Calculate the amount from the aquarium’s volume, then use a marked container or another consistent measuring method so that “about a quarter” remains repeatable from week to week.

Combine related jobs in one routine

1. Observe the fish before disturbing the aquarium.
2. Test ammonia, nitrite and nitrate at least once that week.
3. Remove 25% of the water while siphoning settled waste.
4. Use some removed aquarium water if filter media needs a light rinse.
5. Condition the replacement tap water before adding it.
6. Restore the aquarium cover and confirm that the filter is operating.

Testing and water changes answer different questions. The tests show whether waste compounds are accumulating, while the water change removes part of that accumulation and refreshes the system. A good reading this week is not a reason to abandon the schedule, because regular maintenance helps keep the next reading stable.

Review the routine when nitrate approaches the ceiling of 20 mg/L above tap-water level. Check whether portions have increased, food is being left, solid waste is collecting or the aquarium population has grown faster than the filter can accommodate. Correct the underlying pressure as well as completing the water change.

Keep filter cleaning proportionate. Check for blockages, but do not wash biological media under the tap. A light rinse in removed aquarium water protects more of the beneficial bacterial population while clearing debris that obstructs operation.

At least once every week is the required rhythm for a 25% partial water change, and water should also be tested at least weekly. Additional checks are sensible whenever feeding, stocking, behaviour or filter performance changes. The goal is a predictable system in which a small shift is noticed early, not a cycle of waiting for visible deterioration before acting.

Introduce the fish only to stable water

Before introducing the animal, confirm that the aquarium is filtered, mature, covered and suitable for its adult planning length. Test ammonia and nitrite and proceed only when both read 0 mg/L. Check temperature, pH and hardness against the working guidance rather than relying on the aquarium’s appearance.

Add livestock slowly over time. Every additional fish and every increase in feeding creates more waste, so the beneficial bacteria in the filter need time to respond. A sudden increase can produce new tank syndrome, with ammonia or nitrite rising because the biological filter cannot yet process the new load.

Follow the arrival steps in order

1. Receive the parcel in person and start filming before opening it, keeping the sealed parcel and outer box visible.
2. Open the parcel in one continuous take and show the animal still inside the sealed bag before anything is disturbed.
3. Inspect the parcel and animal on the day it arrives.
4. Float the bag for 20–30 minutes before releasing the fish.
5. Never pour the bag water into the aquarium.

Use checkpoints rather than assumptions

Healthy fish should have clear, bright eyes, undamaged fins, intact scales, no ulcerations or bumps, and swimming behaviour appropriate to the animal. Learn the normal pattern in your own aquarium by watching at the same everyday moments, especially feeding. A consistent point of comparison makes a change easier to recognise.

Warning signs include hanging at the surface, sitting on the bottom, erratic swimming, becoming darker or paler, hiding more than normal, changed aggression, unusually fast or slow gill movement, white spots, fluffy growths, loss of fins or scales, altered body condition, or reduced interest in food.

If a health or behaviour change appears, test water quality first and check filter operation, recent feeding and recent additions. Contact us for further guidance if you remain concerned about the animal’s health. Do not add more fish while ammonia, nitrite, filter performance or unexplained behaviour remains a concern.

Introduction is complete only when the aquarium continues to cope with its new load. Stable readings after the fish enters matter more than a single test taken beforehand, so continue the normal observation, feeding and weekly maintenance routine.

Respond early to behaviour and health changes

Observation works best when it leads to a specific response. Watch swimming, colour, temperament, breathing, outward condition and feeding, then compare each category with the animal’s usual pattern. A single change may have several possible causes, so begin with the measurable parts of husbandry rather than guessing at a disease or treatment.

Match the sign to the first check

Physical changes requiring attention include white spots, fluffy growths, damaged or lost fins and scales, ulcers, bumps, or a noticeable increase or decrease in body condition. Record when the change began and whether it followed a new animal, an increase in feeding, filter maintenance or a missed water change. That sequence helps identify the husbandry pressure that needs correcting.

Test ammonia and nitrite whenever behaviour changes because killifish can be stressed by small amounts of either compound. Both should be 0 mg/L. Also compare nitrate with the tap-water baseline and confirm that it remains no more than 20 mg/L above that normal level.

Do not solve persistent hiding simply by removing every shelter. Cover helps fish avoid pressure, particularly where multiple males or mixed inhabitants are present. Instead, assess whether tank mates are boisterous, whether one fish controls the feeding area and whether shelter is distributed across the aquarium.

Restore water quality, correct feeding, clear a filter blockage or reconsider a poor stocking combination according to what the checks reveal. Obtain a diagnosis before choosing any disease treatment, and keep breeding procedures separate from the routine care plan.

Screen every potential tank mate

Killifish are generally small and peaceful, but they do not appreciate boisterous tank mates. Avoid companions whose normal activity repeatedly chases, crowds or displaces them. A fish that prevents the killifish from reaching food or shelter fails the compatibility screen even when no physical injury is visible.

Some killifish do best in an aquarium centred on their own species because they can be shy and prone to bullying. Others can join a community, but OATA says community killifish should not be kept with other long-finned species because some males may be aggressive towards them. Avoid long-finned tank mates rather than treating them as suitable after screening.

Check five conditions before mixing fish

Size must be considered in both directions. OATA notes that some killifish species, particularly golden panchax, have mouths capable of eating smaller fish. That warning should not be transferred automatically to this animal, but it demonstrates why a generic “small fish community” label is insufficient. Compare the adult size and behaviour of each exact animal in the proposed aquarium.

Do not rely on shared temperature alone. Two animals can fit the same thermal range yet differ in activity, feeding speed or response to long fins. Compatibility remains conditional on the complete aquarium, including its volume, layout, cover, established population and feeding routine.

After introducing any companion, watch feeding access, hiding, colour, swimming and aggression. If a fish is repeatedly excluded from food or shelter, reassess the combination before adding anything else. Choose calm animals with matching water needs, avoid boisterous and long-finned tank mates, then judge the actual interaction rather than treating a tank-mate name as a universal promise.

Plan the group without assuming sex

OATA suggests that killifish need companionship and recommends keeping at least three, normally with two females for each male. The purpose of that ratio is to reduce stress on females or other aquarium inhabitants. It is broad group guidance, so combine it with the adult size, water needs and behaviour of this exact fish.

Plan the aquarium for the intended group before purchasing individual animals. A 40-litre aquarium is OATA’s starting recommendation for a small group of the smallest killifish, while larger aquariums give more stable conditions and more room for cover. The 5 cm maximum recorded length places this species within the smaller size category, but the final capacity must include every other inhabitant and the usable space left after decoration.

Separate three different decisions

• How many purchases: each purchase supplies one animal.
• How many fish the aquarium can support: calculate this from adult sizes, total stocking, filter maturity and usable space.
• What social structure to aim for: use at least three and two females per male as the killifish-group framework, without assuming the sex of an offer that does not name it.

Provide extensive shelter when keeping multiple males. Live plants are ideal, while suitable artificial plants, plant pots or model caves can also provide cover. Spread these features through the aquarium so that several fish can withdraw from attention at the same time.

Add to an established population slowly. Reaching a desired group in one step is less important than protecting water quality while the biological filter adjusts to increased waste and feeding. Test ammonia and nitrite after additions and pause further stocking unless both remain at 0 mg/L.

Watch whether every fish can feed, use shelter and move without persistent pressure. More hiding, changed aggression, altered colour or reduced food intake can indicate that the social arrangement needs attention. First check water quality, then review the amount and distribution of cover and the behaviour of every inhabitant.

A species-centred aquarium is the clearest option when community screening remains uncertain. A community can work only when the proposed animals are calm, use compatible water conditions, are not long-finned and do not dominate feeding or shelter. Group size never overrides those compatibility requirements.

Answer the key buying and care questions

How big does the Red-Chinned Aphyosemion get?

FishBase records the Red-Chinned Aphyosemion at up to 5 cm total length, so use 5 cm when planning the aquarium and assessing the adult sizes of companions.

What size aquarium does Aphyosemion calliurum need?

OATA recommends at least 40 litres for a small group of the smallest killifish. Aphyosemion calliurum reaches 5 cm, so use that group-level figure as the starting point and increase space for other inhabitants or additional shelter.

How many Red-Chinned Aphyosemion should I keep together?

OATA’s killifish guidance suggests at least three, normally with two females for each male. This offer does not guarantee sex, so plan the aquarium around the intended group without assuming a particular ratio from appearance.

Does this killifish suit beginners?

FishBase describes it as easy to maintain in an aquarium, but the keeper must provide a mature filter, a secure cover, stable water, weekly testing and a 25% water change at least once every week.

What does Aphyosemion calliurum eat?

OATA’s killifish guidance recommends good-quality flake or granules, with small live or frozen daphnia, brine shrimp or tubifex for variety. Feed once daily and give only what it can consume within a few minutes.

What temperature and pH does the Red-Chinned Aphyosemion need?

Keep it at 24–26°C and pH 6.0–7.2, the overlap between FishBase’s species range and OATA’s aquarium guidance. OATA’s killifish hardness guidance is 4–12°dH.

Is it aggressive or likely to nip fins?

Killifish are generally small and peaceful, but OATA says some males may be aggressive towards long-finned species. Avoid boisterous and long-finned tank mates, and watch for chasing, exclusion from food or increased hiding.

Which kinds of animals can this fish live with?

Consider calm fish that share its temperature, pH and hardness requirements and will not dominate food or shelter. Avoid boisterous and long-finned tank mates; compatibility with other kinds of animals requires assessment of adult size, space and actual behaviour.

How does it arrive alive in the UK?

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

Consult the principal references

• FishBase: species identity, family, distribution, environment, pH, temperature, conservation category and maximum recorded length.
• Wikipedia: concise natural history and coastal rainforest distribution.
• Ornamental Aquatic Trade Association: broad killifish aquarium, water, feeding, maintenance, social and compatibility guidance.
• RSPCA: general aquarium filtration, biological maturation and waste-processing guidance.