Identification
Thread-like white parasites with Y-shaped end embedded in fish flesh. 1-2cm visible.
Common in goldfish and koi from outdoor ponds.
Manual Removal
Catch fish with wet cloth or net. Hold gently with damp paper towel for grip.
Use tweezers to grasp anchor worm at the embedded end. Pull straight out smoothly.
Disinfect wound site with iodine. Return fish to clean water immediately.
- ✦Sedate fish briefly with clove oil for delicate removal
- ✦Always remove the anchor head — leaving partial worms causes infection
- ✦Wear gloves to avoid skin contact
Medication for Life Cycle
Manual removal kills adults but eggs remain. Use dimilin (diflubenzuron) per product directions, or potassium permanganate dip for severe cases.
Treat for 14-21 days minimum to break the egg-to-adult life cycle.
Pond Applications
Outdoor ponds: dose entire pond with dimilin. Treat in spring before adults grow large.
Quarantine all new koi and pond fish for 3-4 weeks before introducing to pond.