Freshwater Fish

Penguin Tetra

Thayeria boehlkei

Care guide, husbandry, breeding, disease, sourcing, and tankmate intelligence on Penguin Tetra - written by the Fast Aquatics editorial team and cross-verified against vendor records on the live marketplace.

Penguin Tetra at a glance
Adult size: 2.5 inches · Minimum tank/pond: 20 gallons · Difficulty: beginner · Diet: omnivore · Lifespan: 3-5 years.

Penguin Tetra (Thayeria boehlkei) is a freshwater fish kept by aquarists for community + species-specific freshwater displays. Hardy and forgiving of typical beginner mistakes when given proper water chemistry.

Where Penguin Tetra comes from

Penguin Tetra (Thayeria boehlkei) is native to specific tropical and subtropical freshwater systems. The captive-bred Penguin Tetra sold at most LFS comes from generations of farmed stock and is generally hardier and better-acclimated to tank conditions than wild-caught equivalents. Wild specimens are occasionally available for keepers chasing original-bloodline coloration or biotope-accurate stocking.

Penguin Tetra tank size and setup

Penguin Tetra requires a minimum of 20 gallons for healthy adults. The minimum is based on the species' adult size (2.5 inches), territorial range, and behavior pattern. Most Penguin Tetra sold at small juvenile size will reach full adult size within 12-24 months and the system must be sized to the adult, not the juvenile.

For a Penguin Tetra setup: tank sized for the adult footprint, HOB or canister filter rated 4-6x tank volume, dechlorinated water, appropriate temperature heater, and stocking-appropriate hardscape and plants.

Browse our 20-gallon aquarium guide for the complete equipment list.

Water parameters for Penguin Tetra

Penguin Tetra prefers freshwater parameters:
Temperature: 74-80°F
pH: 6.5-7.5
GH: 4-12 dGH
KH: 3-8 dKH
Ammonia + nitrite: Both 0 ppm
Nitrate: Under 20 ppm long-term
Copper: 0 (especially critical for invertebrates)

Use dechlorinator on every water change. Test parameters weekly during cycling, biweekly once stable. Stable consistency beats sliding-scale "ideal" parameters.

What Penguin Tetra eats

Penguin Tetra is a omnivore. Eats a varied diet of pellets, frozen foods, and supplemental greens. Quality flake or pellet (Hikari, New Life Spectrum, Tetra) plus frozen mysis or bloodworms 2-3x weekly produces best color and behavior. Feed Penguin Tetra appropriately for its size + activity level. Overfeeding is the #1 cause of water-quality crashes in tanks of all sizes.

Penguin Tetra tankmates and compatibility

Penguin Tetra works in community tanks with peaceful species in similar size class. Adult-size matters more than purchase-size when planning stocking. Avoid mixing aggressive with passive species.

Browse care guides for tankmate-compatibility tables for Penguin Tetra and similar species.

Penguin Tetra adult size and lifespan

Penguin Tetra reaches 2.5 inches at adulthood with a captive lifespan of 3-5 years with proper care. Most freshwater species live 3-10 years; larger species (oscars, plecos, knifefish) reach 10-20+ years.

Can you breed Penguin Tetra?

Penguin Tetra can be bred in dedicated breeding tanks with appropriate setup and water-chemistry triggers. Research the species-specific breeding requirements before attempting.

Common Penguin Tetra diseases and problems

Penguin Tetra is susceptible to standard freshwater diseases (ich, columnaris, fin rot, bacterial infections). Quarantine new Penguin Tetra for 4 weeks before adding to your display tank. Treat fish in a separate hospital tank to avoid affecting plants and inverts. Most disease outbreaks trace back to poor water quality, chronic stress, or skipped quarantine.

Where to buy Penguin Tetra online

Penguin Tetra is sold at LFS (local fish stores), online retailers, and direct from breeders/wholesalers. Pricing varies widely by source, size, and quality:

Budget tier: $5-25
Mid-tier: $15-50
Premium tier: $40-150

Browse live Penguin Tetra from vetted Fast Aquatics vendors with carrier-tracked overnight shipping (FedEx Priority + UPS Next Day), climate-aware hold logic, and a 4-hour DOA window with photo-evidence claims. Captive-bred or aquacultured specimens cost more upfront but arrive healthier and integrate faster.

Penguin Tetra FAQ

How big does Penguin Tetra get?

2.5 inches at adulthood within 12-24 months.

How long does Penguin Tetra live?

3-5 years with proper care.

What is the minimum tank/pond size?

20 gallons, with larger systems strongly recommended.

Is Penguin Tetra hard to keep?

Penguin Tetra is rated beginner difficulty.

What does Penguin Tetra eat?

Penguin Tetra is a omnivore; appropriate diet matches its natural feeding pattern.

Where can I buy Penguin Tetra?

Browse live Penguin Tetra from vetted Fast Aquatics vendors with carrier-tracked Buyer Protection and a 4-hour DOA window.

How much does Penguin Tetra cost?

$5-150 depending on source and quality.

Do I need to quarantine Penguin Tetra?

Yes - quarantine new Penguin Tetra for 4-6 weeks in a separate tank before adding to your display.

Is Penguin Tetra reef safe?

Not applicable - Penguin Tetra is not a marine reef species.

Other species in the same category with care profiles on Fast Aquatics. Click any name for the full husbandry breakdown.

Chinese Algae EaterGiant DanioAfrican ButterflyfishPea PufferMicrorasbora GalaxyDwarf Pea Puffer

Sources and references

Penguin Tetra taxonomy and care recommendations cross-checked against the following authoritative references and our internal vendor + breeder database.

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More resources for Penguin Tetra keepers

Common diseases
Helpful calculators
Key terms

Browse the full disease database, calculator collection, aquarium glossary, or Q&A library for additional reference.

Deep-dive Q&A on Penguin Tetra

Answers to the questions experienced keepers ask after the basic care guide.

How long does Penguin Tetra take to acclimate to a new tank?

Drip acclimation over 60 to 90 minutes is the safest approach for Penguin Tetra. Match temperature first (15 minute float), then drip 2 to 3 drops per second from the display sump until the bag volume has tripled. Test salinity (or freshwater hardness) at the end - if it is within 0.001 SG (or 2 dGH) of the display, transfer the specimen with a net rather than pouring shipping water in.

What is the best filtration setup for Penguin Tetra?

Aim for biological + mechanical + chemical staging. Canister or sump-driven filtration sized for 5x to 8x display turnover per hour, mechanical floss replaced weekly, and carbon or GAC swapped every 4 to 6 weeks. Penguin Tetra responds well to stable nitrate (under 20 ppm) more than to any specific filter brand - stability beats peak performance.

Does Penguin Tetra need a protein skimmer?

For saltwater specimens, yes - a properly-sized skimmer rated for 1.5x to 2x display volume keeps dissolved organics low and reduces nuisance-algae triggers. Freshwater specimens do not need skimmers; a well-stocked plant grow-out + canister with chemical media achieves the same end. Penguin Tetra kept without adequate organic export tends to show stress within 90 days.

Can Penguin Tetra be kept in a planted tank?

Compatibility with planted tanks depends on the species behavior + water chemistry overlap. Plant-safe specimens leave foliage alone; some pick at soft-tissue plants like vallisneria or anubias. Check the species page profile + the planted-tank compatibility note before stocking Penguin Tetra in a high-tech CO2-injected setup with valuable cultivars.

What is the ideal lighting for Penguin Tetra?

For freshwater specimens with no plant requirements, a basic LED at 30 to 50 PAR at substrate is sufficient and reduces algae. For saltwater + reef specimens, target 100 to 250 PAR depending on photo-tolerance, with a sunrise/sunset ramp + a 8 to 10 hour photoperiod. Penguin Tetra tolerates a wider lighting band than most keepers expect; consistency matters more than peak intensity.

Does Penguin Tetra prefer high or low water flow?

Most aquarium species evolved in moderate flow with localized turbulence rather than uniform high flow. Aim for 20x to 40x display turnover for reef specimens, 4x to 6x for community freshwater. Penguin Tetra shows stress fins (clamped, frayed) when flow is mismatched - dial back if you see this within 14 days of introduction.

What temperature shift will stress Penguin Tetra?

Sustained drift above +/- 2 F from target is the threshold most keepers miss. Penguin Tetra tolerates day-night swings of 1 to 2 F without issue but a 4 F shift over 2 hours triggers ich + bacterial bloom risk. Use a controller-driven heater (not the built-in dial) and a backup thermometer at the opposite end of the tank.

What are the top 3 diseases that hit Penguin Tetra the most?

For freshwater fish: ich, columnaris, and fin rot are the top three; quarantine + UV sterilizer prevents the majority. For marine fish: ich (Cryptocaryon), velvet (Amyloodinium), and bacterial infections; tank-transfer method or copper QT during the 30-day acclimation cycle prevents nearly all outbreaks. For inverts + corals: tissue necrosis, parasitic isopods, and protozoan blooms.

Can Penguin Tetra be bred in captivity?

Captive breeding success varies enormously by species - some breed readily in community tanks (livebearers, cherry shrimp, clownfish) while others have never been captive-bred (most reef fish + most marine inverts). Check the species-specific care guide for the breeding-method note + larval-rearing protocol. Penguin Tetra kept in pairs or small groups often spawns even without intent if conditions are right.

What are the best tankmates to avoid for Penguin Tetra?

Avoid same-species rivals (especially male-male pairings for territorial species), known fin-nippers (tiger barbs, certain pufferfish), and anything that out-competes for food or out-grows the tank. Penguin Tetra also struggles with hyper-aggressive cichlids in freshwater and damselfish in saltwater - both will hold territory at the expense of every other tankmate.

Is Penguin Tetra safe to keep with cleaner shrimp or cleaner wrasses?

Most ornamental specimens accept cleaner shrimp + cleaner gobies; cleaner wrasses (Labroides) often die in captivity and are not recommended. Penguin Tetra kept with cleaner pairs typically benefits from parasite control + stress reduction, but verify the cleaner does not get eaten by checking the species size + temperament chart.

What is the realistic lifespan of Penguin Tetra with proper care?

Captive lifespan tracks closely to wild lifespan when water chemistry, diet, and tankmate stress are managed. Most aquarium fish live 5 to 12 years; long-lived species (large cichlids, pufferfish, some tangs) reach 15+ years. Penguin Tetra kept in a stable, properly-sized system should live within 80% to 100% of the species lifespan ceiling - early death usually traces back to chronic-stress causes (parameters, tankmates, diet) rather than disease.