Velvet disease, also known as gold-dust, rust, or coral disease, is a parasitic fish disease caused by dinoflagellates.
Here's a more detailed breakdown:
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Cause: The disease is caused by dinoflagellate parasites. In marine fish, the culprit is typically of the genus Amyloodinium, while in freshwater fish, it's usually Oodinium.
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Symptoms: The most noticeable symptom is a fine, yellowish-gold or brownish "dust" covering the fish's body. This dust is actually made up of thousands of parasites. Other symptoms can include:
- Clamped fins
- Rapid breathing
- Loss of appetite
- Scratching against objects
- Lethargy
- Cloudy eyes
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Transmission: Velvet disease is highly contagious and spreads quickly in aquariums. The parasites release free-swimming dinospores that attach to new host fish.
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Treatment: Several medications are available to treat velvet disease. Copper-based medications are commonly used, but it is crucial to follow the product instructions carefully, as copper can be toxic to fish, especially invertebrates. Other treatments include malachite green and formalin solutions. Quarantine of infected fish is highly recommended to prevent spread.
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Prevention: Good aquarium hygiene is key to preventing velvet disease. This includes regular water changes, proper filtration, and quarantine of new fish before introducing them to the main tank. Maintaining stable water parameters and reducing stress on fish can also help to prevent outbreaks.
| Feature | Description |
|---|---|
| Cause | Dinoflagellate parasites (Amyloodinium in marine, Oodinium in freshwater) |
| Symptoms | Gold/brown "dust," clamped fins, rapid breathing, lethargy |
| Transmission | Free-swimming dinospores |
| Treatment | Copper-based medications, malachite green, formalin |
| Prevention | Good hygiene, quarantine, stable water parameters |
In summary, velvet disease is a serious parasitic infection in fish characterized by a gold or brown dusting appearance, caused by Amyloodinium or Oodinium parasites, and requiring prompt treatment and preventive measures to control.
