Quick referenceTang Spot Syndrome (TSS) is a head + lateral line erosion specific to tangs + surgeonfish. Linked to stress, low-quality diet, vitamin deficiency, and chronic high nitrate. Reverse with diet + water quality.
Symptoms
Pits along lateral line
Sunken patches on head
Color fade
Refusing food
Sluggish swimming
Worsens with stress
Cause
Multifactorial: 1) Spironucleus protozoa parasites. 2) Vitamin C + A deficiency (poor diet). 3) Chronic high nitrate (>30 ppm). 4) Stress from confinement, aggressive tankmates, undersized tank.
Treatment options
Diet upgrade. Soaked nori + Selcon + Vita-Chem 3x weekly. Add fresh garlic supplement. Switch to NLS Marine Pellet or Hikari Marine Pellet.
Metronidazole. Targets Spironucleus. Soak pellets in metro for 30 min, feed for 7-10 days.
Reduce nitrate. Larger water changes, refugium with chaeto, biopellets if reef tank.
Stop GAC (debated). Some studies link granular activated carbon to HLLE in tangs. Try ceasing GAC for 6-8 weeks.
Always treat in a separate quarantine or hospital tank.
Prevention
Provide adequate tank size (75g+ for yellow tang, 125g+ for hippo, 180g+ for Naso/Vlamingii). Vary diet daily. Maintain nitrate <10 ppm. Reduce stress.
Fatality + outcome
Slow but progressive. Untreated severe TSS causes permanent disfigurement; mild cases reverse fully with treatment.