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Aquarium-fish nutrition — dietary vitamin C deficiency (“broken back”) and iodine deficiency (thyroid hyperplasia)

exotic_aquarium_fish_nutrition

exotic-pet-nutrition 220 tok en 2026-07-28

Aquarium-fish nutrition — dietary vitamin C deficiency (“broken back”) and iodine deficiency (thyroid hyperplasia)

Source: 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.

Claims

  • *[Paraphrased derived summary — non-Open-Access source.]* Poor dietary vitamin C can cause a deformity some farmers call broken-back disease.
  • *[Paraphrased derived summary — non-Open-Access source.]* Iodine deficiency can cause thyroid enlargement (hyperplasia).
  • *[Paraphrased derived summary — non-Open-Access source.]* A key gap is that nutrient needs are established for only a few fish species.
  • *[Paraphrased derived summary — non-Open-Access source.]* At minimum, keepers can classify a fish as carnivore, omnivore, or herbivore.
  • *[Paraphrased derived summary — non-Open-Access source.]* Beyond that, exact protein and lipid needs are mostly unknown.
  • *[Paraphrased derived summary — non-Open-Access source.]* Many fish need more protein than most other vertebrates.
  • *[Paraphrased derived summary — non-Open-Access source.]* Poor nutrition causes stunted growth, deformities, weakened immunity, fatty liver, and disrupted metabolism.
  • *[Paraphrased derived summary — non-Open-Access source.]* Such problems may stem from a clear deficiency or from chronic nitrate exposure and/or ozone use.
  • *[Paraphrased derived summary — non-Open-Access source.]* Fatty liver is common in captive fish, from starvation, high carbs, excess lipid, or rancid feed.
  • *[Paraphrased derived summary — non-Open-Access source.]* Fish need ascorbic acid supplied in the feed.

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License & attribution

Source: 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.

  • https://www.merckvetmanual.com/exotic-and-laboratory-animals/aquarium-fish/nutritional-diseases-of-fish

Sources

Aquarium-fish nutrition — dietary vitamin C deficiency (“broken back”) and iodine deficiency (thyroid hyperplasia)
Source document: Merck Veterinary Manual
Merck Veterinary Manualretrieved 2026-08-01

Verification file: pdf-raw/exotic-health/mvm_fish_nutrition.txt