How to Choose Healthy Zebra Danio, Honey Gourami & 8 More Aquarium Fish

Fish assessed

Zebra Danio · Honey Gourami · Rosy Barb · Salt-and-pepper Corydoras · Celebes Rainbowfish · Senegal Bichir · Midas Cichlid · Bumblebee Cichlid · Twig Catfish · Madagascar Rainbowfish

A store-side guide to Zebra Danio, Honey Gourami and eight more freshwater fish: body condition, warning signs and identity checks.

Honey Gourami in an aquarium
Honey Gourami in an aquarium. Photo: Antoondommerholt at Dutch Wikipedia. View source · CC BY-SA 3.0 · Downloaded provider thumbnail or original as supplied; no further crop or colour change.

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.

Photographs are reference examples, not evidence that an individual fish is healthy. Profiles without a verified aquarium photograph remain text-only.

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. Simon from the Simply Submerged Aquatics team reviewed the published guide for accuracy and completeness within the scope recorded below.

Human reviewerSimonTankWise product lead and freshwater aquarist
Last reviewed

What the human review covered

  • Fish-selection text and identity notes reviewed by Simon.
Meet the team and read the editorial review process

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.
  • 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.

Check 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.

  1. Observe the group from a distance before selecting a candidate.
  2. Compare the candidate with several fish of the same species when possible.
  3. Confirm the store label and scientific identity.
  4. Ask about arrival date, feeding, treatment history, and shared filtration.
  5. Check the species against your aquarium in TankWise before purchase.

Zebra Danio

Danio rerio

Compare this fish with several of the same species when possible. Ask the retailer about feeding, arrival time and the behavior you observe. Brief hiding or a social display is different from persistent exclusion, injury or inability to feed; interpret it alongside breathing, body condition and the whole sales tank.

Honey Gourami

Trichogaster chuna

Honey Gourami in an aquarium
Reference photo: Antoondommerholt at Dutch Wikipedia. View original · CC BY-SA 3.0. Downloaded provider thumbnail or original as supplied; no further crop or colour change

What to notice

Compare this fish with several of the same species when possible. Ask the retailer about feeding, arrival time and the behavior you observe. Brief hiding or a social display is different from persistent exclusion, injury or inability to feed; interpret it alongside breathing, body condition and the whole sales tank.

Rosy Barb

Pethia conchonius

Rosy Barb in an aquarium
Reference photo: Kkonstan. View original · CC BY 3.0. Downloaded provider thumbnail or original as supplied; no further crop or colour change

What to notice

Compare this fish with several of the same species when possible. Ask the retailer about feeding, arrival time and the behavior you observe. Brief hiding or a social display is different from persistent exclusion, injury or inability to feed; interpret it alongside breathing, body condition and the whole sales tank.

Salt-and-pepper Corydoras

Corydoras habrosus

Salt-and-pepper Corydoras in an aquarium
Reference photo: D.W.. View original · CC0. Downloaded provider thumbnail or original as supplied; no further crop or colour change

What to notice

Compare this fish with several of the same species when possible. Ask the retailer about feeding, arrival time and the behavior you observe. Brief hiding or a social display is different from persistent exclusion, injury or inability to feed; interpret it alongside breathing, body condition and the whole sales tank.

Celebes Rainbowfish

Marosatherina ladigesi

Celebes Rainbowfish in an aquarium
Reference photo: Carlos Eduardo Joos. View original · CC BY 2.0. Downloaded provider thumbnail or original as supplied; no further crop or colour change

What to notice

Compare this fish with several of the same species when possible. Ask the retailer about feeding, arrival time and the behavior you observe. Brief hiding or a social display is different from persistent exclusion, injury or inability to feed; interpret it alongside breathing, body condition and the whole sales tank.

Senegal Bichir

Polypterus senegalus

Senegal Bichir in an aquarium
Reference photo: uploaded by en:User:Zhyla. View original · CC BY-SA 3.0. Downloaded provider thumbnail or original as supplied; no further crop or colour change

What to notice

Compare this fish with several of the same species when possible. Ask the retailer about feeding, arrival time and the behavior you observe. Brief hiding or a social display is different from persistent exclusion, injury or inability to feed; interpret it alongside breathing, body condition and the whole sales tank.

Midas Cichlid

Amphilophus citrinellus

Midas Cichlid in an aquarium
Reference photo: George Chernilevsky. View original · Public domain. Downloaded provider thumbnail or original as supplied; no further crop or colour change

What to notice

Compare this fish with several of the same species when possible. Ask the retailer about feeding, arrival time and the behavior you observe. Brief hiding or a social display is different from persistent exclusion, injury or inability to feed; interpret it alongside breathing, body condition and the whole sales tank.

Bumblebee Cichlid

Pseudotropheus crabro

Compare this fish with several of the same species when possible. Ask the retailer about feeding, arrival time and the behavior you observe. Brief hiding or a social display is different from persistent exclusion, injury or inability to feed; interpret it alongside breathing, body condition and the whole sales tank.

Twig Catfish

Farlowella vittata

Twig Catfish in an aquarium
Reference photo: Francesco Loda / CONTERALLY at Italian Wikipedia. View original · CC BY 3.0. Existing local candidate copied without modification; previous resize provenance must be checked.

What to notice

Compare this fish with several of the same species when possible. Ask the retailer about feeding, arrival time and the behavior you observe. Brief hiding or a social display is different from persistent exclusion, injury or inability to feed; interpret it alongside breathing, body condition and the whole sales tank.

Madagascar Rainbowfish

Bedotia geayi

Bedotia geayi and B. madagascariensis are distinct species. Confirm the supplier’s identification; do not treat the names as interchangeable.

Compare this fish with several of the same species when possible. Ask the retailer about feeding, arrival time and the behavior you observe. Brief hiding or a social display is different from persistent exclusion, injury or inability to feed; interpret it alongside breathing, body condition and the whole sales tank.

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.

  • Pseudotropheus crabroFishBase

    Bumblebee-cichlid scientific name.

  • Redescriptions of Bedotia madagascariensis and Bedotia geayiLoiselle and Rodriguez, Zootaxa (2007)

    Public abstract distinguishes the two species; supports the identity caution, not identification of a particular aquarium fish.

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.

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.

Check the fish. Then check the fit.

TankWise screens what your fish needs first, then compares against your aquarium, water, and current livestock before you buy.