{"topic_id":"exotic_aquarium_fish_nutrition","category":"exotic-pet-nutrition","context":"---\ntopic_id: exotic_aquarium_fish_nutrition\ncategory: exotic-pet-nutrition\ntitle: \"Aquarium-fish nutrition — dietary vitamin C deficiency (“broken back”) and iodine deficiency (thyroid hyperplasia)\"\nlang: en\nsource: \"First-hand professional veterinary reference, saved to source_file; paraphrased derived fact summary per COPYRIGHT_POLICY §3. Deepened 2026-08-01.\"\nsource_file: pdf-raw/exotic-health/mvm_fish_nutrition.txt\ndate_parsed: 2026-08-01\ntokens_estimated: 392\nverification:\n  method: paraphrase\n  claims: 10\n  passed: 10\n  date: 2026-08-01\nrecovered: false\npath: exotic-pet-nutrition/exotic_aquarium_fish_nutrition/01_exotic_aquarium_fish_nutrition.md\nsource_document: \"Merck Veterinary Manual\"\ncitation:\n  authority: \"Merck Veterinary Manual\"\n  title: \"Aquarium-fish nutrition — dietary vitamin C deficiency (“broken back”) and iodine deficiency (thyroid hyperplasia)\"\n  url: \"https://www.merckvetmanual.com/exotic-and-laboratory-animals/aquarium-fish/nutritional-diseases-of-fish\"\n  retrieved: \"2026-08-01\"\n  ref: \"\"\n  doc_type: \"professional veterinary reference\"\n  needs_review: false\nlicense: paraphrase\ncopyright_note: \"Source Merck Veterinary Manual (merckvetmanual.com) is a copyrighted veterinary reference and not openly licensed; per COPYRIGHT_POLICY §3 all claims are paraphrased derived fact summaries (numbers and proper nouns preserved, sentences rewritten), not verbatim quotations.\"\nauthority_tier: T3\nauthority_tier_basis: \"T3:vet-ref\"\nauthority_tier_date: 2026-08-04\n---\n\n# Aquarium-fish nutrition — dietary vitamin C deficiency (“broken back”) and iodine deficiency (thyroid hyperplasia)\nSource: Merck Veterinary Manual (merckvetmanual.com), a copyrighted veterinary reference. Per COPYRIGHT_POLICY §3, the points below are paraphrased derived fact summaries: numerical values and proper nouns are preserved from the source, but sentences are rewritten and not quoted verbatim.\n\n## Claims\n\n- *[Paraphrased derived summary — non-Open-Access source.]* Poor dietary vitamin C can cause a deformity some farmers call broken-back disease.\n- *[Paraphrased derived summary — non-Open-Access source.]* Iodine deficiency can cause thyroid enlargement (hyperplasia).\n- *[Paraphrased derived summary — non-Open-Access source.]* A key gap is that nutrient needs are established for only a few fish species.\n- *[Paraphrased derived summary — non-Open-Access source.]* At minimum, keepers can classify a fish as carnivore, omnivore, or herbivore.\n- *[Paraphrased derived summary — non-Open-Access source.]* Beyond that, exact protein and lipid needs are mostly unknown.\n- *[Paraphrased derived summary — non-Open-Access source.]* Many fish need more protein than most other vertebrates.\n- *[Paraphrased derived summary — non-Open-Access source.]* Poor nutrition causes stunted growth, deformities, weakened immunity, fatty liver, and disrupted metabolism.\n- *[Paraphrased derived summary — non-Open-Access source.]* Such problems may stem from a clear deficiency or from chronic nitrate exposure and/or ozone use.\n- *[Paraphrased derived summary — non-Open-Access source.]* Fatty liver is common in captive fish, from starvation, high carbs, excess lipid, or rancid feed.\n- *[Paraphrased derived summary — non-Open-Access source.]* Fish need ascorbic acid supplied in the feed.\n---\n## License & attribution\n\nSource: Merck Veterinary Manual (merckvetmanual.com) is a copyrighted veterinary reference and is not openly licensed. Per COPYRIGHT_POLICY §3, every claim above is a paraphrased derived fact summary (numbers and proper nouns preserved, sentences rewritten), not a verbatim quotation.\n\n- https://www.merckvetmanual.com/exotic-and-laboratory-animals/aquarium-fish/nutritional-diseases-of-fish","sources":["exotic-pet-nutrition — Aquarium-fish nutrition — dietary vitamin C deficiency (“broken back”) and iodine deficiency (thyroid hyperplasia) (retrieved 2026-08-01)"],"source":{"authority":"exotic-pet-nutrition","title":"Aquarium-fish nutrition — dietary vitamin C deficiency (“broken back”) and iodine deficiency (thyroid hyperplasia)","url":"https://www.merckvetmanual.com/exotic-and-laboratory-animals/aquarium-fish/nutritional-diseases-of-fish","retrieved":"2026-08-01","ref":"","doc_type":"official PDF","source_document":"Merck Veterinary Manual","verification_file":"pdf-raw/exotic-health/mvm_fish_nutrition.txt"},"source_document":"Merck Veterinary Manual","source_file":"pdf-raw/exotic-health/mvm_fish_nutrition.txt","trust":{"authority_tier":"T3","fidelity":"paraphrase","license":"paraphrase","display_grade":"B"},"tokens_estimated":220,"generated_at":null,"tip":"Use /api/v1/topics to discover more topics. /api/v1/nutrient for precise single-point queries. /api/v1/cross_compare for 2-3 standard comparisons."}