AQUAPEDIA / FEEDING EVIDENCE
What medaka keepers report feeding in the U.S. market
14 U.S.-market or English-language firsthand observations, from microscopic fry foods to adult formulations and live cultures. This is not a U.S. popularity poll.
FIRST-PARTY AMERICAN EVIDENCE
Documented U.S. Medaka breeder and facility feeding
These are first-party accounts at five identifiable U.S. ornamental fish/shrimp operations, not a national sample. Named diets count only when the operator says it feeds them. Retail stock is not evidence of feeding in farm tubs. Reused product-page text is not an independent observation. All claims are attributed; no breeder was contacted.
SNR Medaka USAfirst person breeder husbandry guidance no brands
Reported foods or recommendation: Appropriately sized commercial floating pellets (unspecified brand)
Reported schedule: Summer twice daily; spring/fall once daily; outdoors in winter stop when fish no longer surface.
Scope: Oryzias latipes, adult ornamental medaka
Limits: Cannot infer that SNR feeds Hikari/GEX/Comet products listed in its retail collection; no measured growth comparisons.
Provenance: Breeder's own site advises food finished in 1–3 minutes, warns that grinding food into excessive powder can harm water quality.
SNR Medaka USAbreeder first person recommendation not verified ration
Reported foods or recommendation: Itosui finely ground medaka fry powder — explicitly recommended, not documented as their own exclusive food; Very small fry feed when actively hunting; an older article mentions PSB liquid
Reported schedule: Guides differ: first days observationally and small amounts ~1–2 times/day; other old content says small amounts twice/day. No universal days-of-life prescription.
Scope: Oryzias latipes (newly free-swimming fry)
Limits: Seller's claims for probiotics, garlic, PSB 'immune boost' etc are NOT separately verified trials, and PSB liquids should not be assumed a complete nutritional diet.
Provenance: Direct first-party educational guide and older breeder blog, not dated SKU purchase receipts.
Medaka Farmus breeder husbandry guidance no named rotation
Reported foods or recommendation: Commercially available floating medaka food (generic)
Reported schedule: Once or twice per day; individual product guidance says amount eaten in 3–5 min.
Scope: Oryzias latipes, tank/pond-bred ornamental medaka
Limits: Retail listing for imported Hikari newborn food indicates US product availability, NOT their own broodstock menu. No specific food rotation/feeding trial identified.
Provenance: Seller identifies California outside-bred generations and includes feeding advice for own strains; generic fish feeding recommendation, not proven feeding log.
U.S. MAKER LABELS / NOT BREEDER ADOPTION
Medaka fry-to-breeder pellet sizes
Hikari USA manufacturer sizes and guaranteed nutrients, not proof any particular American medaka breeder uses these feeds or that their branded performance claims beat alternatives. Choose by actual fry mouth size and observation; never extrapolate a universally fixed feeding day.
| Formula | Maker stage | Label granules | Maker guaranteed nutrients | Maker advice and source |
|---|---|---|---|---|
| Medaka No-Mai Baby | Newly feeding fry up to approximately 10 mm per maker | ≤ 0.2 mm | Protein ≥48%; fat ≥12% | Manufacturer advises at least 5 tiny feedings/day when used as directed; not universal recommendation for every fry culture. Original source 1 ↗ |
| Medaka No-Mai Next | Juveniles (maker's transition from Baby at at least 10 mm) | 0.21–0.37 mm | Protein ≥48%; fat ≥12% | Manufacturer says feed multiple times/day adjusting to temperature, and refers to Baby for newborn fry. Original source 1 ↗ |
| Medaka No-Mai Breed | Adult breeders generally above approximately 25 mm per maker | 0.38–0.6 mm | Protein ≥50%; fat ≥11% | Manufacturer says feed multiple small meals adjusted for temperature; performance and reproduction promises are unverified maker claims. Original source 1 ↗ |
PRIMARY EVIDENCE / BATCH 4
What primary sources say about medaka feeding
U.S. EPA historical larval protocol: first-instar brine shrimp nauplii are sometimes ingestible by medaka fry as early as 24–48 hours after hatch: cited larval gape about 0.32–0.36 mm and nauplius width 0.20–0.24 mm, but prey length is greater. Age, strain, orientation and observed swallowing matter. EPA manual ↗
2022 study correction: laboratory medaka in the CON custom treatment received 50% flakes and 50% live Artemia. Beef-liver paste was assigned to the adult platyfish ration and should not be described as a medaka ingredient. Russo et al. Methods ↗
2020 medaka broodstock ARA experiment: a high-ARA diet yielded 79% hatch vs 50% in control and heavier hatchlings, but higher mortality by day seven. Experimental units were mg of ARA per gram of total fatty acids, not grams of finished feed or a safe aquarium-supplement prescription. Broodstock ARA study ↗
Interpretation: do not turn historical lab diets into fixed feeding-day rules. Hatch percentage and subsequent fry survival are distinct outcomes, and first-instar prey must be size-matched.
SOURCES AND LIMITATIONS
Limits on the American sample
Only the 2024 “Best food for the price for USA” conversation explicitly concerns US buying. Other English-language Reddit accounts are not verified US residents. A retailer listing confirms availability and ingredients but not what breeders actually use. Growth outcomes in hobby reports are uncontrolled anecdotes.
US-budget firsthand discussion ↗ · Detailed medaka-fry thread ↗
SOURCES AND LIMITATIONS
14 foods and culture approaches
Aquarium Co-Op Easy Fry and Small Fish Foodfry to small juveniles · commercial micro feed
Evidence classification: keeper report us location unconfirmed
Interpretive boundary: One American-market retailer formula; newborn fry may need further grinding/sieving; not all mouths can ingest its original particles.
Reported observation 1 ↗ · Reported observation 2 ↗ · Maker or study 1 ↗
Hikari First Bitesfry · commercial fry powder
Evidence classification: keeper report us location unconfirmed
Interpretive boundary: Used as tiny-fry powder in reported U.S. retailer discussions; acceptance varies and surface dust may foul.
Reported observation 1 ↗ · Reported observation 2 ↗ · Maker or study 1 ↗
Golden Pearls microdiet (size graded)fry to juvenile · commercial size graded microdiet
Evidence classification: keeper report us location unconfirmed
Interpretive boundary: Reports cite 5–50, 50–100 and 200–300 micrometer offerings; buyer must verify actual grade and composition per listing.
Ken's .2 mm fry foodfry to juvenile · commercial micro feed
Evidence classification: explicit US discussion
Interpretive boundary: U.S.-price discussion claims use of a 0.2 mm feed; formula and pack date not independently checked.
Ultra Fresh Newborn Fish powderfry · commercial powder
Evidence classification: explicit US discussion
Interpretive boundary: Reported by U.S. price discussion author; the user guessed brand origin; do not label made in USA.
Fluval Bug Bites small-fish formulajuvenile to adult · commercial insect based
Evidence classification: explicit US discussion
Interpretive boundary: A respondent to USA-budget discussion uses this as a routine feed and live BBS several days weekly; user locale not verified.
Imported Hikari medaka gold pack 130 gjuvenile to adult · imported medaka feed
Evidence classification: explicit US discussion
Interpretive boundary: Do not assume the 2024 Amazon price or gold-pack variant is the same SKU as current Hikari Medaka No-Mai Breed.
Hikari Medaka No-Mai Breed (US label)adult breeding · manufacturer specialist feed
Evidence classification: us manufacturer label no keeper count
Interpretive boundary: U.S. manufacturer guaranteed protein minimum 50%, fat minimum 11%, grain ~0.38–0.6 mm; marketing effects unproven independently.
Sera Micron powderfry · commercial micro feed
Evidence classification: keeper report us location unconfirmed
Interpretive boundary: Fish fry keeper mentions; grade current label needed for feeding stage matching.
Otohime A/A1 imported starterfry to juvenile · imported hatchery feed
Evidence classification: keeper report us location unconfirmed
Interpretive boundary: One user's observed rapid initial growth is uncontrolled anecdote; no end-size or brand efficacy claim.
Greenwater and established-pond microfaunanewly free swimming fry · live nursery ecosystem
Evidence classification: keeper report us location unconfirmed
Interpretive boundary: Greenwater is an ecosystem, not a complete standardized formulation; check density, oxygen, water quality and suitable live prey.
Reported observation 1 ↗ · Reported observation 2 ↗ · Maker or study 1 ↗
Paramecium / infusoria / mixed microscopic preynewly free swimming fry · cultured live microfauna
Evidence classification: keeper report us location unconfirmed
Interpretive boundary: Culture identification, contamination and ingestion need assessment; no exact survival benefit supported from anecdote.
Freshly hatched Artemia naupliifeeding juvenile to adult when size compatible · live hatched food
Evidence classification: aquaculture guidance plus community
Interpretive boundary: Rinse/sieve hatched nauplii; first-day medaka mouth-size and development variable; supplier-specific cyst hatchability unverified.
Reported observation 1 ↗ · Reported observation 2 ↗ · Maker or study 1 ↗
Moina live water fleaslarger fry to adult · live cultured prey
Evidence classification: keeper report us location unconfirmed
Interpretive boundary: Use suitably small neonates; culture hygiene and prey size differ by species and culture conditions.
SOURCES AND LIMITATIONS
Stage guidance and what still requires verification
Free-swimming newborns: infusoria/paramecia or confirmed very fine feed according to actual mouth gap. Larger fry: size-graded commercial powders or Golden Pearls with small live cultures. Older fry/juveniles: freshly hatched, rinsed Artemia only once they can capture and swallow it; Moina neonates if size appropriate. Adult breeders: nutritionally complete feed and varied clean live prey. Monitor uneaten food and water quality throughout; do not assign fixed universal ages or infer growth superiority from individual reports.
Related: Controlled composite medaka diet trial ↗ · U.S. Hikari No-Mai Breed label ↗