White Spots on Bettas: A Guide to Ich (White Spot Disease)
White spots on betta fish typically signal Ichthyophthiriasis (Ich), caused by the protozoan Ichthyophthirius multifiliis. Below is a detailed breakdown of causes, symptoms, and treatment strategies:
I. Causes and Symptoms
Pathogen
Caused by the parasitic protozoan Ichthyophthirius multifiliis (commonly called "Ich").
Spherical parasites (0.8mm diameter) form visible white cysts on the body, fins, or gills.
Typical Symptoms
Early Stage: Fish rubs against objects; small white spots first appear on fins; reduced activity.
Mid-Late Stage: Spots spread across the body; white mucus coats the skin; rapid breathing (gill distress); potential mass mortality.
II. Trigger Factors
Temperature Fluctuations: Common in fall/winter or during water changes with >4°F (2°C) temperature shifts. Ich thrives at 57–77°F (14–25°C).
Poor Water Quality: Infrequent water changes or acidic water (low pH).
Weakened Immunity: Stressed or malnourished fish are more susceptible.
III. Treatment Methods
Heat Therapy
Gradually raise water temperature to 86°F (30°C) and maintain for 7 days. High heat inhibits Ich reproduction.
Salt Bath
Quarantine infected fish; soak in 1% aquarium salt solution (1 tablespoon per 1 gallon) for 20–30 minutes daily, 3–5 days.
Case Study: In a 15cm tank, daily 1/3 water changes with trace salt resolved Ich in 1 week.
Medication Options
Methylene Blue: Use alongside 86°F (30°C) water for effective results.
Mercuric Nitrate: 0.1ppm bath (2ppm for 2–3 hours in severe cases), but note its toxicity—use as a last resort.
IV. Prevention Strategies
Stable Temperature: Maintain water above 77°F (25°C); limit temperature changes to <4°F (2°C) during water changes.
Regular Water Changes: Replace 1/4 of water every 3–4 days (more frequent in tanks without filters).
New Fish Quarantine: Disinfect new arrivals with potassium permanganate or salt water before introducing to the main tank.
V. Differential Diagnosis
Velvet Disease: Spots are finer (resembling dust); treat with specific protozoan medications.
Pepper Disease: Dense, coffee-colored spots; use salt baths for treatment.
Note: If white spots coincide with raised scales or fin rot, bacterial infection may be present—combine with antibacterial meds.
Translation Notes:
Used (°F) with metric conversions for clarity.
Replaced with "aquarium salt" to specify safe use for fish.
Added "aquarium" before "salt" to avoid confusion with table salt.
Structured sections with Roman numerals for logical flow, ideal for care guides.
Highlighted "last resort" for mercury-based meds to emphasize safety precautions.