This reviewed buying guide covers 10 freshwater fish. A photograph appears only when the image shows the exact species alive in an aquarium or other suitable submerged setting and its reuse record is complete; the reviewed profile remains available without substitute imagery while a qualifying photo is sourced.
Use the guide at the retailer to compare breathing, posture, body condition, skin, fins, eyes, and behavior with what is normal for the species. Look at the whole sales system, ask about feeding and recent arrivals, and quarantine every new fish before it shares water or equipment with an established aquarium.
This is an observation guide, not a diagnosis. A fish that looks healthy can still carry pathogens, while transport, lighting, age, sex, and social position can change normal appearance and behavior.
Content transparency
AI-generated draft, human-reviewed publication
This guide was drafted with generative AI used to organize research and prepare an initial version. The AI output was not treated as an authority or source. Dan from the Simply Submerged Aquatics team reviewed the published guide for accuracy and completeness within the scope recorded below.
What the human review covered
- Species identities, scientific names, and public fish-selection copy
- Healthy signs, purchase warning signs, and diagnostic limitations
- Species-normal behavior and temperament distinctions
- Source records, image licences, and TankWise app statements
Key takeaways
- Watch the complete sales tank before choosing an individual fish.
- Compare breathing, posture, body condition, skin, eyes, fins, and response rather than relying on one sign.
- Allow for normal species behavior, including resting, hiding, schooling, feeding patterns, territorial display, and social position.
- Confirm the scientific identity and eventual aquarium needs before buying.
- Only approved exact-species aquarium photographs are shown; a reviewed profile remains available without an image when photography is pending.
- A healthy-looking fish still needs a suitable aquarium; compare it with your saved tank in TankWise before buying.
Store-side field guide
10 fish at a glance
Match the store label to the fish, then jump straight to its healthy and warning signs.
Yoyo LoachBotia almorhaePristella or X-ray TetraPristella maxillaris
Chocolate GouramiSphaerichthys osphromenoidesAfrican Leaf FishPolycentropsis abbreviata
Red-head Tapajos EartheaterGeophagus pyrocephalusCompressor CichlidAltolamprologus compressicepsRed Phantom TetraHyphessobrycon sweglesiAgassiz's Dwarf CichlidApistogramma agassiziiCheck the sales tank before the fish
Watch before anyone taps the glass, feeds the fish, or reaches for a net. Compare breathing, posture, body condition, skin, fins, eyes, and behavior across the group rather than choosing only by color or activity.
Pause if a tankmate is dead, unable to balance, extremely thin, ulcerated, heavily spotted, covered in growth, or breathing with pronounced effort. Ask when the fish arrived, whether it has eaten, and whether nearby tanks share filtration.
A feeding response is useful evidence, but it does not prove that a fish is disease-free. Quarantine every new arrival separately and avoid sharing wet equipment with the established aquarium.
- Observe the group from a distance before selecting a candidate.
- Compare the candidate with several fish of the same species when possible.
- Confirm the store label and scientific identity.
- Ask about arrival date, feeding, treatment history, and shared filtration.
- Check the species against your aquarium in TankWise before purchase.
Cherry Barb
Pethia titteya
Review these species-specific points together: Body weight, clear skin, fin condition, balanced social behavior.
Confirm that schooling, chasing, colour change, and social position are explained without treating every shy or subordinate fish as ill.
Common Pleco
Hypostomus plecostomus
Review these species-specific points together: Exact identity, full belly, intact mouth, credible lifelong housing plan.
Confirm that resting, hiding, bottom-feeding, nocturnal activity, barbel condition, and breathing behaviour are described in a species-appropriate way.
Yoyo Loach
Botia almorhae
What to notice
Review these species-specific points together: White spots, hollow belly, barbel injury, social chasing versus bullying.
Confirm that resting, hiding, bottom-feeding, nocturnal activity, barbel condition, and breathing behaviour are described in a species-appropriate way.
Pristella or X-ray Tetra
Pristella maxillaris
Review these species-specific points together: Body clarity, full belly, fin condition, cohesive schooling.
Confirm that schooling, chasing, colour change, and social position are explained without treating every shy or subordinate fish as ill.
Chocolate Gourami
Sphaerichthys osphromenoides
What to notice
Review these species-specific points together: Darkening, body weight, skin condition, stress sensitivity.
Confirm that normal surface air-breathing is distinguished from repeated gasping or breathing distress.
African Leaf Fish
Polycentropsis abbreviata
Review these species-specific points together: Body weight, skin pattern, fin integrity, ambush-predator response.
Confirm the species' normal posture, activity period, social behaviour, hiding, feeding response, and territoriality before labelling behaviour abnormal.
Red-head Tapajos Eartheater
Geophagus pyrocephalus
What to notice
Review these species-specific points together: Correct identity, head pits, gill rate, substrate-sifting and social behavior.
Confirm that territorial display, pair or group dynamics, mouthbrooding where relevant, and persistent bullying are clearly separated.
Compressor Cichlid
Altolamprologus compressiceps
Review these species-specific points together: Jaw alignment, body weight, fin damage, ambush-predator behavior.
Confirm that territorial display, pair or group dynamics, mouthbrooding where relevant, and persistent bullying are clearly separated.
Red Phantom Tetra
Hyphessobrycon sweglesi
Review these species-specific points together: Body weight, red color, intact fins, male display.
Confirm that schooling, chasing, colour change, and social position are explained without treating every shy or subordinate fish as ill.
Agassiz's Dwarf Cichlid
Apistogramma agassizii
Review these species-specific points together: Hollow belly, gill rate, fin damage, territorial pressure on females.
Confirm that territorial display, pair or group dynamics, mouthbrooding where relevant, and persistent bullying are clearly separated.
Sources and further reading
These references provide scientific or technical background and disclose how TankWise works. External references do not imply that every current TankWise catalog value was sourced from, or reviewed by, those organizations. See the checker methodology and known limits for that distinction.
- Selection of FishMerck Veterinary Manual
Veterinary-reviewed guidance on assessing a fish, its environment, skin, fins, eyes, movement, and alertness before purchase.
- Selecting a FishAmerican Veterinary Medical Association
Supports checking adult needs, body condition, breathing, behavior, and the wider sales system, while recognizing that a normal-looking fish may still carry disease.
- Pet Fish HealthRSPCA
Species-aware health context for appetite, breathing, alertness, eyes, fins, scales, and swimming.
- FishBase Species SearchFishBase
Scientific identity, distribution, biology, size, and cited species information used alongside other qualified sources.
- TankWise checker methodology and known limitsSimply Submerged Aquatics
The inputs, rules, safety limits, and uncertainty boundaries behind the TankWise aquarium comparison.
- Cherry Barb species recordFishBase
Species reference for Cherry Barb (Pethia titteya).
- Common Pleco species recordFishBase
Species reference for Common Pleco (Hypostomus plecostomus).
- Yoyo Loach species recordFishBase
Species reference for Yoyo Loach (Botia almorhae).
- Pristella or X-ray Tetra species recordFishBase
Species reference for Pristella or X-ray Tetra (Pristella maxillaris).
- Chocolate Gourami species recordFishBase
Species reference for Chocolate Gourami (Sphaerichthys osphromenoides).
- African Leaf Fish species recordFishBase
Species reference for African Leaf Fish (Polycentropsis abbreviata).
- Red-head Tapajos Eartheater species recordFishBase
Species reference for Red-head Tapajos Eartheater (Geophagus pyrocephalus).
- Compressor Cichlid species recordFishBase
Species reference for Compressor Cichlid (Altolamprologus compressiceps).
- Red Phantom Tetra species recordFishBase
Species reference for Red Phantom Tetra (Hyphessobrycon sweglesi).
- Agassiz's Dwarf Cichlid species recordFishBase
Species reference for Agassiz's Dwarf Cichlid (Apistogramma agassizii).
Frequently asked questions
Can a fish that looks healthy still carry disease?
Yes. Visual screening can identify reasons to pause, but it cannot prove that a fish is free of pathogens or parasites. Quarantine new arrivals and avoid sharing wet equipment with an established aquarium.
Should I buy from a tank containing a dead or visibly distressed fish?
Pause and ask what happened, whether the tanks share filtration, and what action the retailer is taking. Choosing another fish from the same water does not remove shared exposure.
Is unusual color, hiding, or resting always a sign of illness?
No. Lighting, transport, age, sex, social position, and species-normal behavior can change appearance and activity. Review breathing, posture, body condition, skin, fins, eyes, and the condition of the whole tank together.
Why does this guide include 10 fish rather than ten?
Only fish with a licensed live or submerged exact-species reference photograph were included. Fish awaiting suitable photography remain unpublished instead of being represented by stock or substitute species.
Where does TankWise fit?
This guide helps screen the individual fish. TankWise then compares the species' needs with your aquarium, water, and current livestock. It does not diagnose illness or guarantee compatibility.