| What It Is | Amyloodinium ocellatum parasite |
| Looks Like | Fine gold/dusty film; rapid breathing |
| Danger | Very high — kills fast |
| Treatable | Yes, but act immediately |
| Reef-Safe Cure | None — treat in QT |
Overview
Marine velvet (Amyloodinium) is ich’s deadlier cousin. It’s a parasite that can kill an entire tank of fish in days, sometimes before obvious spots ever appear — fish often die of gill damage and suffocation first. Velvet moves so fast that recognizing it early and acting the same day is the difference between saving fish and losing all of them.
Symptoms
A fine gold, rust, or grey dusty sheen over the body (finer than ich’s distinct spots, like powdered sugar), very rapid breathing, flashing, clamped fins, loss of appetite, and fish hanging near the surface or in high flow gasping. Sudden multiple deaths with heavy breathing and a dusty film is velvet until proven otherwise.
How to Treat It
- Act immediately — velvet doesn’t give you the days ich does. Move fish to quarantine at the first suspicion.
- Copper at therapeutic level is the mainstay; a formalin bath can buy time for heavily-infected fish struggling to breathe.
- Treat the full course and keep the display fishless (about 6 weeks) so the parasite starves out.
- Support the fish — strong aeration in the QT helps fish whose gills are compromised.
Prevention
Same as ich, but the stakes are higher: quarantine every fish and observe them before they ever reach your display. Velvet is almost always introduced by an un-quarantined new fish. A quarantine period would have caught it in isolation instead of in your show tank.
Common Mistakes
Mistaking it for ich and waiting: velvet kills far faster — when in doubt, treat as velvet. Not having a QT ready: with velvet there’s no time to go shopping; a spare tank and copper on hand save fish. Returning fish to the display too soon: the parasite persists — keep the display fishless for the full fallow period.
Related Guides
Marine Ich (White Spot Disease): Identify & Treat · Why You Need a Quarantine Tank
Frequently Asked Questions
How is marine velvet different from ich?
Velvet, Amyloodinium, is far faster and deadlier. It looks like a fine dusty or velvety coating rather than distinct white spots, and fish often breathe heavily and die within 1 to 3 days, sometimes with no obvious spots at all.
How do I treat marine velvet?
Immediate copper treatment in quarantine, or chloroquine phosphate. Speed is everything, because velvet can wipe out a tank in days, so act at the first sign of heavy breathing or sudden losses.
How do I prevent velvet?
Quarantine every new fish. Velvet is almost always introduced by an unquarantined fish, so a proper quarantine period is the single best defense against a tank wipe.