Tucan Fish (Chalceus erythrurus)

Choose a fast upper-water fish with room to move

The Tucan Fish, Chalceus erythrurus, is a streamlined, pelagic member of Chalceidae from the Amazon and Solimões systems through to the Ucayali drainage in Peru. It can reach 24.5 cm standard length and suits a keeper prepared to provide a large, securely covered aquarium with open swimming room. Its long body, reflective flanks and colourful tail give it the familiar Pink-Tailed Chalceus trade appearance, while its speed makes swimming space more important than elaborate decoration.

FishBase identifies Chalceus erythrurus as a freshwater, pelagic member of Chalceidae and records a maximum of 24.5 cm standard length. Treat that maximum as the decisive planning figure even though the fish selected for dispatch is much smaller.

This is one of the larger tetra-like fishes placed within our tetras collection, but it should not be planned like a small community tetra. The combination of adult length, speed, jumping ability and social choices makes it most appropriate for a purpose-built display.

Use the selector to choose the dispatch size

One purchase supplies one animal in the selected option. The live size selector carries the labels 3-4 cm, 5-6 cm and 6-7 cm; use it to see the choice attached to the purchase you are making. The size you select is the size supplied, not the adult size.

A dispatch measurement is useful for preparing an introduction, but it does not change the long-term requirement. A fish dispatched at 3-4 cm still needs a plan based on a possible 24.5 cm standard length, open swimming room and a secure cover. Do not use the smallest selectable grade as a reason to begin with a small temporary aquarium if that aquarium cannot safely accommodate its speed or future growth.

Keep the offer details separate

• Purchase unit: one fish per selected purchase quantity.
• Size choice: follow the exact label shown by the live selector.
• Adult planning figure: up to 24.5 cm standard length.
• Social plan: keep one specimen or a group of more than six, rather than a small group.

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

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

Plan the aquarium around adult speed and size

Seriously Fish recommends a 120 × 45 cm base and approximately 243 litres as the smallest aquarium that should be considered. The reason is practical: this fish can turn on real speed and may injure itself in cramped quarters. Aquarium length, unobstructed lanes and safe turning room therefore matter alongside volume.

Check whether the species fits your plan

The 243-litre figure is a starting benchmark for the species, not an automatic capacity for every stocking plan. A group of more than six adults and any companion fish add both bodies and movement, so the finished aquarium must be planned around their combined swimming space and biological load. A taller tank cannot compensate for an inadequate base when the fish needs horizontal room.

Choose the social arrangement before purchasing equipment. One specimen avoids disputes within a small group. A group means at least seven fish because groups of two to six tend to scrap. That choice affects the required footprint, filter capacity and number of suitable upper-water territories, even though the same water range applies.

Set stable water targets before introduction

The species aquarium range is 22–26°C, pH 6.0–7.0 and 5–15 dGH. OATA’s tetra and pencilfish sheet is group guidance and gives 22–27°C, pH 6.5–8.0 and 4–12 dGH. Use the overlap as a practical routine target: 22–26°C, pH 6.5–7.0 and 5–12 dGH. This keeps routine values within the species range while also following the narrower part of the group guidance.

Measure the aquarium rather than assuming its values from the local water supply. Our water chemistry guide explains what each result means, while the water matcher helps compare measured values with these targets.

Respond to results in the right order

• If ammonia or nitrite is detectable, pause livestock additions and restore biological filtration.
• If pH or hardness sits outside the target, establish a safe adjustment plan before adding the fish rather than making abrupt changes afterwards.
• If temperature varies through the day, stabilise the heater and confirm the result with repeated readings.
• If nitrate rises quickly, review stocking, feeding and the weekly maintenance routine together.

Confirm stability across several checks

Take readings at consistent times so the results can be compared properly. A single temperature reading within range does not show whether the aquarium remains stable overnight or after maintenance. Check again after the heater has completed several normal cycles and after replacement water has mixed throughout the tank.

Use the same measured approach for pH and hardness. If successive readings remain within pH 6.5–7.0 and 5–12 dGH, keep the routine steady instead of chasing one exact point. When a result shifts, check recent water changes, equipment adjustments and test technique before altering the aquarium. This sequence reduces the risk of responding to one isolated reading with a sudden chemical change.

Leave open lanes and secure every escape route

Keep the central and upper parts of the aquarium open enough for uninterrupted swimming. Sand, branches and floating plants can create an effective South American-style setting, but décor is secondary to usable space. Place cover around edges rather than building a dense obstacle course across the route used by a fast fish.

Fit the cover before the fish arrives

A very well-fitting cover is essential because the Tucan Fish is a renowned jumper. Check the entire rim, including gaps around cables, pipes and filter returns. A hood that looks closed from the front may still leave an escape route at the back. Recheck it after equipment servicing because moved cables can open new gaps.

Before settling on a decorative plan, imagine the fish travelling from one end of the tank to the other at speed. Remove any arrangement that forces a sharp turn through a narrow gap. Equipment should remain accessible for weekly checks without dismantling the swimming area.

When planning a group, multiply the need for movement rather than merely checking whether seven bodies fit within the stated volume. More than six fish must be able to pass, turn and feed without being compressed into the same small surface area. The smallest recommended aquarium is therefore a species benchmark, while the final group aquarium should reflect the full adult stocking plan.

Run a dry layout check

1. Place the branches, plants and equipment before filling the aquarium.
2. Trace a broad route along the upper length of the tank without passing through a narrow gap.
3. Check that each end leaves enough open space for a fast turn.
4. Open and close the cover to confirm that cables and pipes remain inside sealed cut-outs.
5. Make sure filter servicing can be completed without moving décor into the swimming lane.

Repeat this check after adding or pruning plants. Floating growth can be useful around the edges, but it should not spread across the entire surface or obstruct the route used for swimming and feeding. Keeping the layout simple also makes it easier to spot uneaten food, damaged equipment or a newly opened lid gap.

Match filtration to the aquarium’s real volume

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. The aquarium must have a well-established filter before the Tucan Fish is introduced.

For an aquarium of approximately 243 litres, the species guidance recommends turnover of four to five times the aquarium volume each hour, corresponding to about 970–1,215 litres per hour. Apply the same calculation to the real water volume of a larger aquarium rather than choosing a filter solely from the tank’s marketing name.

These calculations are flow-planning figures. Filter performance can be affected by media, pipework and blockages, so confirm that water continues to circulate throughout the aquarium and check the filter routinely. Position the return so it moves water without sacrificing the broad swimming lane.

Mature the system before stocking

Prepare the biological filter before livestock arrives and confirm zero ammonia and zero nitrite. Add fish gradually because the bacterial population must increase as stocking and feeding rise. Our first tropical tank guide covers aquarium preparation and filter maturation step by step.

Do not rely on clear-looking water as a substitute for testing. Ammonia and nitrite are dissolved wastes, so a visually clean aquarium can still present a serious welfare risk when the filter is immature or overloaded.

Protect water quality with a weekly routine

Test ammonia, nitrite and nitrate at least once each week. Record the results so a gradual change is visible before it becomes a crisis. Ammonia and nitrite should remain at zero mg/l, while nitrate should not exceed 20 mg/l above the normal tap-water level.

Make a 25% partial water change at least once every week and use a siphon to remove solid waste from the substrate. Treat replacement tap water with a conditioner that removes chlorine or chloramine before it enters the aquarium. Match the replacement water closely enough to avoid an abrupt change in temperature or chemistry.

Clean the filter without stripping its bacteria

1. Check the intake and outlet for blockages during the weekly maintenance session.
2. Remove the scheduled 25% of aquarium water into a clean container.
3. If the filter media needs cleaning, rinse it lightly in that removed aquarium water.
4. Do not run it under the tap because any chlorine or chloramine present may kill beneficial bacteria.
5. Restart the filter and confirm that normal circulation has resumed.

Link maintenance decisions to the test results. Detectable ammonia or nitrite means the system is not processing waste safely; reduce the pressure on the filter and correct the cause before adding more livestock. A rapidly rising nitrate result points towards accumulated waste, excessive feeding, insufficient water changes or a stocking load that needs review.

Watch flow as well as chemistry. A blocked intake reduces circulation and biological processing, while a neglected substrate can hold uneaten food and solid waste. The purpose of the routine is not to make the aquarium look polished for one day; it is to keep its biological processes stable from week to week.

Use the weekly record to spot a trend

Compare each result with the previous week before completing maintenance. For example, zero ammonia, zero nitrite and a modest nitrate rise indicate a different decision from detectable ammonia after a new livestock addition. In the first case, continue the established routine. In the second, pause further additions, confirm flow and review the increase in feeding and waste.

Write down the amount of water changed and whether the filter intake needed clearing. If nitrate climbs faster over several weeks despite the same 25% change, inspect feeding portions, trapped debris and the complete stocking load together. Changing one factor at a time makes the cause easier to identify and prevents several unnecessary adjustments from obscuring the result.

Feed a varied diet in one controlled daily meal

In nature, Chalceus erythrurus feeds primarily on insects and aquatic crustaceans. Dried aquarium foods are usually accepted, but a good proportion of the diet should be meaty. Suitable examples named for the species include prawn, mussel, bloodworm and chopped earthworm, alongside a quality dried food.

Use the OATA group routine for portion control: feed once each day and offer only what the fish can consume within a few minutes. That gives the Tucan Fish time to take a complete meal without leaving food to decay. Uneaten food breaks down and adds toxic waste, so a fish that rushes to feed should not be rewarded with an oversized portion.

Use appetite as an observation tool

Watch the whole feeding event rather than dropping food and walking away. Confirm that the fish reaches food, swallows normally and does not lose condition. In a group, check individuals rather than judging success from the speed of the first fish at the surface.

If food remains after a few minutes, reduce the next portion and remove leftovers where practical. If appetite falls, test the water and compare swimming, breathing, colour and body condition with the fish’s normal pattern. Feeding more heavily is not a safe response to unexplained weight loss or reduced interest.

Adjust portions without losing variety

Begin with a controlled daily serving and observe how much disappears within a few minutes. If food remains, make the next serving smaller rather than shortening the observation period. If every item is taken immediately, continue watching long enough to confirm that each fish in a group has eaten before deciding whether the portion needs a small adjustment.

Rotate the supported foods across meals instead of combining every choice into one oversized feed. A quality dried food can provide the staple, while prawn, mussel, bloodworm or chopped earthworm supplies the meaty variety described for the species. Keep the once-daily schedule consistent so changes in appetite are easier to recognise and uneaten food does not place avoidable pressure on filtration.

Prepare the aquarium before opening the transport bag

Complete the setup before the delivery day. The filter should be established, ammonia and nitrite should read zero, temperature should sit within 22–26°C, and the lid should already be secured around every cable and pipe. Check the pH and hardness as well so the fish is not being moved into an unsuitable system.

Follow the arrival sequence

1. Arrange for someone to receive the parcel so live fish are not left unattended.
2. Start filming before the parcel is opened and continue in one take, showing the sealed parcel and outer box, the parcel being opened and the fish still inside the sealed bag.
3. Float the bag in the aquarium for 20–30 minutes.
4. Release the fish after the temperature-acclimatisation period.
5. Do not pour transport-bag water into the aquarium.
6. Close and recheck the aquarium cover immediately.

These steps come from our delivery and Live Arrival Guarantee policy, which also sets out the current delivery process and claim requirements.

Make the first checks objective

Observe swimming, breathing, colour, fins, scales and interest in food. A change matters most when compared with that individual fish’s developing normal pattern. Keep the first test results beside the aquarium so later readings can be compared with a baseline.

Add further livestock slowly. Each addition increases waste and feeding, and the biological filter must expand to process the extra load. This matters especially when the final plan is a group of more than six Tucan Fish: the social recommendation does not remove the need to match additions to the established filter’s capacity.

Treat changed behaviour as an early warning

Learn how the fish normally swims, breathes, feeds and uses the aquarium. Regular observation makes a meaningful change easier to identify than a single generic checklist. Healthy fish should have clear, bright eyes, intact scales and undamaged fins, without ulcerations or bumps.

Begin with water tests because ammonia and nitrite are toxic and should remain at zero. Confirm that the filter is running, the intake is clear and the temperature is stable. Physical damage also warrants a check of lid gaps, hard obstacles and interactions between fish.

Do not combine medicines on the basis of appearance alone. Different problems can produce similar changes in behaviour, colour or appetite. Record what changed, when it began and the relevant water readings; contact us for guidance on health changes after those immediate checks are complete.

Build a useful observation record

Note the time, water readings and the precise change rather than writing only that the fish looks unwell. Record whether the change affects one fish or the whole group, whether it began before or after feeding, and whether recent maintenance, décor movement or livestock additions occurred. These details help separate an aquarium-wide water problem from an injury or social interaction affecting one individual.

Repeat the immediate checks after restoring normal flow or correcting an identified water-quality problem. Compare swimming, breathing and feeding with the earlier note instead of relying on memory. If the fish develops white spots, fluffy growths, continuing loss of scales or a sustained loss of appetite, keep the observations and water results together so the next decision is based on the full pattern.

Choose either one specimen or a group of more than six

The Tucan Fish does best as a single specimen or in a group containing more than six fish. Smaller groups tend to scrap, so two to six is not a sensible compromise between solitary and group keeping. A group plan therefore begins at seven.

Make that decision before choosing the final aquarium. The approximately 243-litre, 120 × 45 cm benchmark is the smallest aquarium considered for the species; it should not be treated as a promise that seven adults plus companions will fit. A group of fast fish needs enough open water for individuals to pass, turn and withdraw from a dispute.

Check a proposed group in three stages

1. Plan around a possible 24.5 cm standard length for each fish rather than dispatch measurements.
2. Calculate filter turnover at four to five times the real aquarium volume per hour.
3. Leave enough upper-water area that the group is not forced into a narrow route around décor or companions.

Observe the group at feeding time and between meals. Scrapping, persistent displacement from the surface or repeated collisions indicate that the social or spatial plan needs attention. A secure cover remains essential for every group size because sudden movement may end at the water’s surface.

Screen companions by size, position and temperament

In a large community, consider similarly sized characins such as Leporinus, Metynnis, Mylossoma and Brycon, as well as large loricariids, pimelodiids and cichlids such as Geophagus or Satanoperca. These are conditional examples rather than automatic matches: compare adult size, water requirements, temperament, swimming level and the total space required by every species.

Avoid other surface-dwelling species unless the aquarium is huge. Avoid timid or long-finned fish because broad tetra guidance warns that larger, boisterous species may nip or overwhelm them. Fish small enough to be eaten also belong outside this community plan.

Compatibility remains dependent on aquarium dimensions, group sizes and individual behaviour, not common names alone. Ask us for a stocking and compatibility assessment with the tank dimensions, measured water values, filter capacity, existing livestock and intended group sizes.

Work through the screens in order

Start with adult size because dispatch measurements can make two young fishes look better matched than they will be later. Next compare the full water ranges; a companion that cannot remain within 22–26°C, pH 6.5–7.0 and 5–12 dGH should leave the plan at that stage. Then compare swimming level and temperament before considering the combined filter load.

For example, a similarly sized fish with matching water needs can still be unsuitable if it depends on the same crowded surface route. A bottom-oriented companion may reduce that spatial conflict, but it still requires enough floor area, suitable temperament and adequate filtration. Treat every successful screen as one condition rather than a guarantee. After introduction, check whether each fish can reach food, use its normal area and withdraw without persistent pursuit.

Check the essential Tucan Fish decisions

How big does Chalceus erythrurus get?

The Tucan Fish can reach 24.5 cm standard length, so plan its aquarium around that recorded maximum rather than its dispatch size.

What size aquarium does Chalceus erythrurus need?

Seriously Fish recommends at least approximately 243 litres with a 120 × 45 cm base, open swimming lanes and a very well-fitting cover.

How many Chalceus erythrurus should I keep together?

Keep one specimen or a group of more than six; avoid groups of two to six because smaller groups tend to scrap.

Is Chalceus erythrurus suitable for beginners?

It suits a keeper prepared to manage a fish reaching 24.5 cm, an aquarium of at least approximately 243 litres, a secure cover and a deliberate solitary or seven-plus social plan.

What does Chalceus erythrurus eat?

Feed once daily with quality dried food plus meaty variety such as prawn, mussel, bloodworm or chopped earthworm, limited to what it eats within a few minutes.

What temperature and pH does a Tucan Fish need?

Use 22–26°C, pH 6.5–7.0 and 5–12 dGH as the routine overlap between Seriously Fish species guidance and OATA group guidance; keep ammonia and nitrite at zero mg/l.

Is this fish aggressive or likely to nip fins?

Groups of two to six tend to scrap, and OATA warns that larger, boisterous tetra-like fish may nip or overwhelm timid or long-finned fish, so avoid those combinations.

Which animals can it live with?

Consider similarly sized Leporinus, Metynnis, Mylossoma or Brycon, large loricariids, pimelodiids, Geophagus or Satanoperca only after matching adult size, water, temperament and space; avoid other surface dwellers unless the aquarium is huge.

How does it arrive alive in the UK?

Tropical Fish Co’s delivery policy requires someone to receive the parcel and continuous filming from the sealed parcel through opening, with the fish still in its sealed bag; then float the bag for 20–30 minutes and never pour the bag water into the aquarium.

References for identity, care and welfare

• FishBase: Chalceus erythrurus — identity, family, distribution, environment and maximum recorded standard length.
• Seriously Fish: Chalceus erythrurus — aquarium footprint, volume, water ranges, filtration, diet, grouping and compatibility.
• OATA: tetras and pencilfish — group water, feeding, maintenance, introduction and observation guidance.
• RSPCA: aquarium environment — biological filtration and nitrogen-waste welfare guidance.
• Tropical Fish Co delivery policy — receipt, acclimatisation and Live Arrival Guarantee terms.