Teugelsi Bichir (Polypterus teugelsi)

Teugelsi Bichir: a large Cross River predator

Teugelsi Bichir is the aquarium name for Polypterus teugelsi, a valid species from the upper Cross River system in Cameroon. It is an elongated, bottom-oriented bichir with separate dorsal finlets, heavy ganoid scales and a reticulated dark pattern over the upper body. The species was formally described in 2004 and remains one of the more recently named members of the family Polypteridae.

The current trade specification is for a 5-7 cm juvenile. One cart quantity means one fish unless the selected option explicitly says otherwise; sex, a pair and an exact colour pattern are not guaranteed. A small sale size must not be mistaken for a small adult. The 2019 family revision records 415 mm standard length and 467 mm total length, so this is a long-term large-aquarium commitment rather than a routine community-fish purchase.

Plan around adult footprint, a completely secure lid, dependable biological filtration, surface access and tank mates that cannot be swallowed. The fish may rest quietly in cover for much of the day and become more active in lower light, but calm behaviour does not make it suitable for small companions. Check the live buy box for current price and availability.

Verified facts and practical care targets

The locality, identity, sale size and recorded maximum are source-backed. The temperature, pH, hardness and aquarium dimensions are conservative captive-planning targets, not claims that every part of the Cross River has identical chemistry or that litres alone determine welfare. Floor area, turning room, filtration and lid security remain decisive.

Identity, taxonomy and the Cross River name

Polypterus teugelsi was described by Ralf Britz from the upper Cross River system in Cameroon. Earlier Cross River material had been compared with Polypterus retropinnis, but the 2004 description established a separate species. The comprehensive 2019 revision of living polypterids retains P. teugelsi as one of thirteen valid species of Polypterus.

“Cross River Bichir” is useful because it points to the verified drainage rather than inventing a wider African range. The Lower Guinea freshwater-fish handbook describes the species as endemic to the upper Cross system in Cameroon. A retail fish cannot be assigned to a precise collecting point from its photograph, so this listing uses the scientifically supported drainage-level origin and does not claim a locality that the supplier has not supplied.

Bichirs are actinopterygian, or ray-finned, fishes in the family Polypteridae. They are unusual within living fishes because they combine separate dorsal finlets, ganoid scales, spiracles and paired lungs. Calling them “prehistoric-looking” describes their appearance; it should not be confused with saying an aquarium fish is unchanged from a fossil ancestor. The living species has its own modern evolutionary history.

Colour, body shape and responsible image reading

The original species description highlights a network of irregular black marks across the dorsal and dorsolateral body, orange ventral colour and very dark pectoral fins. The later revision describes a beige to brown-orange upper body with irregular dark anastomosing marks, a lighter lower body and seven to nine dorsal-fin spines or finlets. Pattern contrast changes with age, lighting, stress and the individual fish.

The body is notably elongated compared with many other bichirs, with the upper jaw projecting slightly beyond the lower jaw. A row of separate dorsal finlets creates the familiar serrated outline, while the rounded tail and muscular body support short bursts rather than continuous open-water cruising. Thick scales do not make the skin immune to sharp decor, poor water or rough handling.

The gallery image is a representative aquarium scene and must not be used as proof of sex, exact locality, maturity or the precise markings of the fish supplied. Juveniles can look less strongly patterned than mature examples, and transport can temporarily mute colour. Use the photograph to understand the general form only; every fish can differ naturally in colour and pattern.

What to check on arrival

• Steady balance and controlled movement along the bottom.
• Regular surface visits without continuous frantic gasping.
• Clear eyes and fins without rapidly worsening damage.
• A body that is neither sharply pinched nor persistently swollen.
• Gradual interest in cover and food once the fish has settled.

Sale size, adult length and long-term planning

A 5-7 cm juvenile is easy to underestimate. The largest measured specimen in the modern revision reached 415 mm standard length and 467 mm total length. Standard length excludes the caudal fin, so the two figures are not contradictory. Use the larger total-length figure when checking turning room, lid clearances and whether a proposed companion may eventually fit in the bichir’s mouth.

Growth rate cannot be guaranteed from sale size. Temperature, feeding, genetics, health and previous conditions all affect development. A juvenile can begin in a well-managed grow-on aquarium, but buying one without an adult enclosure already planned risks a costly and stressful move later. The final system should have a long, wide base rather than gaining most of its volume through extra height.

Aquarium size, lid design and surface access

For one fish, about 600 litres and a base around 200 x 60 cm are a practical starting floor, not an invitation to stop planning. A full adult, a mixed bichir group or other large fish benefits from a longer and wider aquarium. A tall narrow tank may meet a volume figure while still providing poor turning space. Measure the usable base after decor, not only the external glass dimensions.

A completely secure lid is essential. Seal gaps around cables, filter pipes and feeding hatches without blocking ventilation. Bichirs can use surprisingly small openings, especially at night or during disturbance. They also need unobstructed access to the water surface because polypterids possess paired lungs and take atmospheric air. Leave a suitable humid air space beneath the cover and never trap the fish below a sealed internal shelf.

Use a mature biological filter sized for a carnivorous fish and the total stocking load. Current should circulate waste and maintain oxygen without forcing the fish to fight a torrent across every resting place. Keep ammonia and nitrite at zero, manage nitrate with appropriate maintenance and remove uneaten food before it decays. Air breathing is an adaptation, not permission for polluted water.

Secure-system checklist

• Every cable and pipe gap is physically covered.
• The lid cannot be lifted by the fish.
• Surface access remains open and easy to reach.
• Filter intakes are safe for the current sale size.
• Heaters are guarded or positioned to prevent prolonged contact.
• Decor remains stable if the fish pushes beneath it.

Water parameters, cycling and acclimation

A stable captive target of 24-28°C, pH 6.5-7.5 and roughly 5-12 dGH preserves the established aquarium guidance for this listing. These figures are practical operating ranges rather than measurements attached to the supplier’s exact stock locality. Keep the fish toward the stable middle of the chosen range instead of repeatedly adjusting water to hit an arbitrary decimal.

The aquarium must be biologically mature before arrival. Test ammonia, nitrite, nitrate, pH and temperature with dependable methods, and confirm that the filter can process the existing feeding load. A large empty-looking predator tank can still be immature. Do not rely on elapsed calendar time alone; cycling is proved by water results and filter performance.

On delivery, follow the current livestock instructions supplied with the order. Minimise sudden temperature or chemistry changes, keep lights low and provide immediate access to a dark retreat. Do not add shop water to the display unnecessarily. A newly moved juvenile may refuse the first meal, so observe breathing, balance and body condition before responding with repeated food.

Substrate, cover, lighting and maintenance access

Use fine sand or smooth rounded gravel that will not abrade the belly as the fish rests and moves across the base. Provide broad caves, stable wood and shaded routes, but preserve enough open floor for turning and feeding. Secure every heavy object directly so digging or pushing cannot undermine it. Avoid narrow ornaments in which a growing fish could become trapped.

Hardy plants can work when attached to wood or stone, and floating cover can soften bright light. The layout should be designed for the fish and for maintenance, not only for a photograph. Leave clear routes for a siphon, visual checks and retrieval of uneaten food. A densely packed hardscape that hides waste or prevents inspection is poor long-term design for a large carnivore.

Subdued to moderate lighting usually makes lower-level activity easier to observe. Use a predictable day/night cycle and avoid sudden bright light when the fish is resting. Dim transitions and several dark retreats are more useful than a permanently unlit tank. The keeper still needs enough visibility to judge body condition, injuries and feeding.

Feeding a juvenile and adult bichir

This is a carnivorous fish. Build the aquarium diet around complete sinking carnivore pellets plus varied suitable frozen or fresh aquatic foods such as prawn, mussel and other appropriately sized items. Earthworms from a safe source can add variety. Cut food to a size the fish can swallow safely and place it where a shy juvenile can find it without competing with faster surface feeders.

Feed according to body condition, age, water temperature and the energy density of the food rather than a rigid universal schedule. Juveniles usually need smaller, more regular meals than adults. Mature fish should not be stuffed simply because they respond strongly. Remove uneaten remains, and adjust the next portion if food is left or the body becomes excessively heavy.

Do not use feeder fish as the default diet. They can introduce pathogens, make nutrition inconsistent and encourage purchases that are difficult to quarantine. Avoid mammalian or poultry meat as routine food. A varied aquatic-protein diet and a quality complete pellet are easier to balance and keep cleaner than one repeated ingredient.

Behaviour and everyday observation

Expect a bottom-oriented fish that often rests beneath wood or beside a cave and becomes more exploratory under subdued light. Bichirs use smell and close-range senses effectively when locating food. A settled individual may learn the feeding routine, but “recognising” a routine should not be turned into claims about human-like intelligence or guaranteed hand feeding.

Occasional surface visits are normal because the fish breathes atmospheric air as well as using its gills. Repeated frantic surfacing, loss of balance or inability to stay submerged is not normal simply because it is an air-breathing species. Check temperature, ammonia, nitrite, oxygenation, obstruction and physical condition immediately.

Quiet daytime behaviour is not proof that companions are safe. Opportunistic predation often occurs when lights are low. A fish that has coexisted with a small companion for weeks may still swallow it after growth or a chance encounter. Compatibility must be judged against the largest likely mouth size and the smallest body depth in the aquarium.

Tank mates and predation risk

The safest default is a species-focused aquarium. In a genuinely large mixed display, companions must be robust, non-nipping, able to feed without harassment and too deep-bodied to be swallowed. Similar length alone is not enough: a long slender fish may fit in the mouth more easily than a shorter deep-bodied fish. Provide separate retreats and watch every animal at feeding time.

Other bichirs can sometimes coexist when sizes are compatible and floor space is generous, but that is not a guarantee of harmony. Avoid crowding several bottom predators into the minimum aquarium. Large catfish, cichlids or gouramis are not automatically suitable; aggression, adult size, water needs and feeding competition must be assessed for the exact species.

Small tetras, rasboras, livebearers, shrimp and similarly sized fish should be treated as prey-risk choices, not community companions. Ropefish are relatives, but their slender body and different social needs make them a comparison species rather than an automatic tank mate. Lungfish should never be suggested as a casual companion simply because both groups breathe air.

Sex, pairing and breeding limits

The 5-7 cm fish is not sold as sexed. Mature male bichirs generally develop a broader anal fin, but juvenile sexing is uncertain and two fish ordered together are not a guaranteed male-female or compatible pair. Do not buy multiple juveniles on the assumption that they can remain indefinitely in the same minimum-sized aquarium.

The sources used here do not provide a detailed species-specific breeding protocol. Do not rely on exact water-change triggers, hatching times or parental-role claims for this stock. Treat any breeding attempt as an advanced project and consult direct species-specific evidence before proceeding.

If reproductive behaviour is suspected, prioritise welfare and observation. Ensure both fish can retreat and feed, keep water stable and have a separation plan. Eggs or fry should not be expected merely because two fish coexist. Any future breeding section should be expanded only when a direct, reliable P. teugelsi source supports the details.

Health checks, quarantine and when to seek help

Good prevention starts with mature filtration, a secure low-stress layout, suitable food and observation before tank mates are introduced. Quarantine new fish and equipment where practical, but do not use an arbitrary number of days as proof that an animal is disease-free. Watch appetite, waste, breathing, balance, skin, eyes and fins over time.

Abrasions can follow rough decor or attempted escapes. Poor water can cause lethargy, excess mucus, heavy breathing and secondary infection. Refusal of one meal after transport may be settling behaviour; persistent refusal combined with weight loss or abnormal breathing needs investigation. Test the environment before assuming every symptom requires medication.

Do not guess drug doses or combine treatments. Bichirs have unusual anatomy, and products vary in concentration and safety. Use a qualified aquatic veterinarian or an experienced aquatic-health professional for diagnosis where illness is persistent, severe or unclear. Keep the product label, water-test results and a timeline of symptoms available.

Compare Teugelsi with other bichirs

Choosing between bichir species should begin with verified adult size and the aquarium you can maintain, not colour alone. Teugelsi is notable for its elongated body, Cross River origin and reticulated pattern. Senegal Bichir is often presented as a more familiar starting comparison, while Saddled and Ornate bichirs demand their own large-fish planning. Check each linked product page for its current size and availability.

First 30 days: a staged settling plan

The first month should be treated as an observation period rather than a race to increase feeding or add tank mates. A newly moved juvenile has already experienced packing, transport, new water chemistry and a different day-night routine. Give it a quiet, secure system with established biological filtration, subdued areas and easy access to the surface. Keep the lid fully closed from the moment the fish is introduced; temporary gaps for airline, heater or filter cables are still escape routes.

Offer food only when you can observe the response. Remove uneaten pieces promptly, because a carnivore meal can deteriorate water quality faster than a small flake feed. A fish that ignores one meal after transport is not automatically ill; look at the whole pattern, including posture, breathing, skin, buoyancy and the next feeding response. Persistent refusal, repeated regurgitation, loss of condition, redness, sores or abnormal breathing deserves investigation rather than random treatment.

If quarantine is available, keep equipment separate and use it as a period of calm observation. Record the date, feed offered, approximate amount eaten and any visible change. A short written log is more reliable than memory and makes it easier to explain the timeline to an aquatic veterinarian or experienced fish-health professional if help is needed.

Filtration and maintenance for a large carnivore

Good filtration is not only about the filter's advertised aquarium volume. The complete system must capture solid food fragments, support stable biological processing and remain easy enough to service that maintenance actually happens. Choose equipment with capacity in reserve, but avoid turning the whole aquarium into a high-velocity channel. The fish should have calmer resting zones as well as well-oxygenated water.

Test ammonia and nitrite whenever a system is new, disturbed or behaving unexpectedly, and monitor nitrate as a trend rather than waiting for a single alarming reading. Compare results with feeding, maintenance and stocking notes. Sudden changes often reveal a missed meal, clogged mechanical stage, dead tank mate or reduced flow before the aquarium looks visibly dirty.

During each service, account for the fish before lifting the lid and prepare tools in advance so the cover is open for the shortest practical time. Siphon around shelters without collapsing them, inspect hidden corners for food, and verify that heaters, intakes and return pipes remain firmly secured. Recheck every lid panel and cable opening when maintenance is finished.

Reading body condition and adjusting food

Feeding advice works best when it is tied to the individual fish rather than a rigid number of meals. View the animal from above and from the side under normal lighting. The body should not look sharply pinched behind the head, but a permanently distended abdomen is not the goal either. Compare condition over several weeks using photographs taken from a similar angle; daily impressions can be misleading.

Use varied, appropriately sized sinking carnivore foods and suitable frozen or fresh aquatic foods rather than relying on mammal or bird meat. Do not use feeder fish as a routine shortcut: they can introduce disease, make nutrition difficult to balance and encourage unnecessary predation in a community. If several bottom-feeding fish share the aquarium, place food where each individual can be observed and remove leftovers after the feeding window.

Choosing an adult system: footprint before litre count

The practical baseline in this guide is about 600 litres with a footprint around 200 x 60 cm, but litres alone do not prove suitability. A tall, narrow aquarium may hold the same volume while providing less turning room and bottom area. Prioritise length and width, then check that decor does not reduce the usable footprint to a corridor.

Plan the lid, filtration, cabinet access and maintenance route before purchase. The adult system should permit the fish to turn without bending around hard structures, reach the surface directly and retreat into more than one stable shelter. Leave a clear route for siphoning and equipment removal. If the intended aquarium cannot meet those conditions at the species' documented adult scale, choose a smaller species rather than relying on a future upgrade with no date or space assigned.

Before ordering

• The aquarium is mature and tested, not only recently filled.
• The adult footprint and upgrade plan are already realistic.
• Every opening in the lid is sealed while surface air remains accessible.
• The current 5-7 cm fish cannot enter the filter intake or become trapped in decor.
• Existing tank mates are too large to swallow and will not nip or outcompete it.
• Sinking food is ready and leftovers can be removed easily.
• A quarantine and health-observation plan is available.
• The current buy box, stock status, dispatch information and Live Arrival Guarantee terms have been checked.

One order quantity is one unsexed fish. The supplier sale size is 5-7 cm, but natural variation and measurement method mean an individual may not be identical to a photograph or an exact ruler mark. Check the live buy box and current delivery terms, and contact the store before purchase if a specific sale or dispatch detail is essential.

Common planning mistakes

Scientific and husbandry basis

The sold fish is identified as Polypterus teugelsi at 5-7 cm. Scientific descriptions support the accepted name, Cross River distribution, diagnostic appearance and recorded adult measurements. The water and aquarium figures below are practical captive targets informed by specialist care summaries rather than collection-site measurements. Published recommendations vary, so this guide uses a conservative adult footprint and treats the figures as planning ranges, not guarantees.

• Britz (2004): original description of Polypterus teugelsi - species identity, upper Cross River type locality and diagnostic live colour.
• Moritz and Britz (2019): revision of living Polypteridae - valid status, morphology, distribution records and maximum measured length.
• Fresh and brackish water fishes of Lower Guinea: Polypteridae account - upper Cross River endemism and diagnostic summary.
• Eschmeyer's Catalog of Fishes species record - independent catalogue confirmation of the accepted name and original description.
• Fischlexikon: Polypterus teugelsi husbandry summary - 200 cm aquarium length and a 24-28°C, pH 6.5-7.5, 5-12 dGH captive range.
• The Aquarium Wiki: Cross River Bichir care summary - moderate care classification, a 473-litre reference and overlapping captive water guidance.

Sources checked 27 July 2026. Scientific sources describe the species; they do not certify the sex, collection point, pair status, exact colour or future adult size of one retail fish. Read the current product interface and delivery page for live price, availability and dispatch terms.