This a hard pic to work with as fish is somewhat distant in the photo. My suspicion is velvet.
Velvet spots on the fish are much finer than the spots seen in Ich making it harder to catch until in cases too late to treat.
Some behaviors associated with a fish with velvet are :
- Scratching body against hard objects
- Fish is lethargic
- Loss of appetite and weight loss
- Rapid, labored breathing
- Fins clamped against the body
- rapid breathing and mucus around the gills
Fish with velvet will typically stay at the surface of the water, or remain in a position where a steady flow of water is present in the aquarium. As the disease progresses outwards from the gills, the cysts then become visible on the fins and body. The fine consistency suggests this is velvet. Although these cysts appears as tiny white dots often the first sign of ich, what sets velvet apart from other types of ich is that the fish have the appearance of being coated with what looks like a whitish or tan to golden colored, velvet-like film given the name Velvet Disease.
Remove fish from main tank and place them into a QT with added aeration. Treat the fish in the QT with a copper-based medication. While many remedies contain the name as ich treatment, assure it targets Oodinium. My choice is coppersafe or copper power at 2.25-2.5 therapeutic level at 80 degrees for a FULL 30 days monitored by a reliable copper test kit such as Hanna Brand (no api brand).
. Assure the medication you use states treats Oodinum.
With velvet, fish will scratch body against hard objects, lethargic behavior, Loss of appetite and weight loss, Rapid, labored breathing, Fins clamped against the body, and typically stay at the surface of the water, or remain in a position where a steady flow of water is present in the aquarium.
Ich always shows spots at first. They are less visible in some species, and long term, the spots coalesce into mucus, but it is never seen in just the gills. After flukes, bacterial gill disease is probably the second most common of these symptoms. Velvet is purely a gill disease and does stop fish from eating, but the fish breath really fast.
Cuprion is tricky to use, it is toxic if you don’t dose it just right. In fact, I think their advertising even tells you this….you would need an accurate low dose copper test.