Treatment: Coral dip every new zoa, manual removal, target inspection
What is zoa-eating nudibranchs
Zoa-Eating Nudibranchs is a common aquarium disease/pest affecting reef tanks (zoas). Recognizing it early and treating quickly is the difference between losing a single fish and losing an entire tank.
Symptoms to watch for
zoa polyps closing/dying, small camouflaged nudis. Watch for behavior changes (reclusive, refusing food, color loss) as early warning signs - even before visible symptoms appear, fish stress patterns indicate something is wrong.
Treatment protocol
Coral dip every new zoa, manual removal, target inspection. Always treat in a separate hospital tank to protect invertebrates, coral, and beneficial bacteria. Follow medication protocol exactly - underdosing produces resistance, overdosing creates new problems.
Prevention
Quarantine new fish for 4-6 weeks before adding to your display tank. Stable parameters + appropriate stocking + adequate filtration prevent the chronic stress that makes fish susceptible to disease in the first place.
When to escalate
If symptoms persist beyond expected treatment duration, parasites/symptoms reappear after treatment, or the disease spreads despite isolation, escalate to a fish-specific veterinarian or experienced reef keeper. Aquatic veterinarians offer prescription medications (chloroquine, levamisole) not available over-the-counter.
Zoa-Eating Nudibranchs FAQ
Is zoa-eating nudibranchs contagious?
Pests can spread between corals; isolate infested specimens immediately.
Can I treat in the display tank?
For most diseases - no. Copper kills inverts, antibiotics destroy beneficial bacteria. Always treat in a hospital tank.