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Fin Rot

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Medaka

About this condition

A Columnaris bacterial infection that causes tail fins to turn white and dissolve. Poor water quality and overcrowding increase risk; it can progress to the body if left untreated.

Common symptoms

  • Tail fin dissolving and turning white
  • Fin edges becoming white
  • Fin splitting and tearing

Common causes

  • Columnaris bacterial infection
  • Water quality deterioration
  • Overcrowding

Prevention (husbandry & daily care)

Water quality management, proper stocking density, regular water changes.

Related species guide

Browse the species guide for this animal

When to see a vet

Consider consulting a specialist store within a few days

What can a specialist store do?

A veterinarian or specialist will assess the severity and advise on water quality improvement and an appropriate treatment plan. Prompt consultation is recommended when multiple medaka show symptoms.

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