Just as a post note, here is what I found on flukes
Dont know if it helps or not
Freshwater flukes occur in all parts of the world on numerous species of fishes. By their name, you might expect them to be visible to the naked eye, however, they are microscopic. Flukes occur in two major classes, that is; Dactylogyrus, the famed Gill Fluke, and the second class is Gyrodactylus, the Skin fluke. There are certain morphological differencesbetween these two classes. Under the microscope, you would notice that the Dactylogyrus fluke has several pairs of eye-spots, and they also lay eggs. In a specimen of Gyrodactylus, you would only see an embryo inside, with no eyespots in the adult.
The class Dactylogyrus occurs in over a hundred different species. The Dactylogyrus lays its eggs under the gill cover and are swept into the water. The eggs hatch and tiny larva can infect a new host.
Gyrodactylus flukes reproduce by producing live young which set about parasitizing the host immediately.
Flukes can cause Ulcer Disease. Other parasites can transmit and cause ulcerations, but none so effectively as the FLUKE.In the process of attacking a host, the flukes dig deeply into the epidermis and gill tissue with their haptens. Regardless of species, the flukes are known to carry and inoculate pathogenic bacteria. Flukes from certain areas, and on certain batches of fish carry more and more dangerous and virulent bacteria on their haptens. In this way, discovery of a few flukes on the gills or skin can account for rapid and mortal outbreaks of Aeromonas and Pseudomonas funrunculosis (Ulcer Disease). It is generally agreed that heavy fluke infestations affecting more than one fish are usually caused by overcrowding, poor water quality or polluted water - that is water with a high organic content and stress. Under ideal circumstances, these parasites can rapidly multiply.
The fish response to the irritation caused by flukes is similar to any other irritant, whether it is parasites or chemical. Initially there will be rubbing and flashing. As the disease reaches a more advanced stage the fish will become lethargic - which is the point when some people think the problem has gone away.
Control of flukes has become increasingly easy with contemporary medicine. Potassium permanganate has been shown to be effective when applied as an eight hour bath at one gram per hundred gallons (2 ppm) or when dosed daily at 2 ppm for five days consecutively. Alternatively, some have found that despite it's negative effects on fish and filter, that Formalin is effective in eradication of fluke adults, with a second treatment (three days later) serving as clean-up for the emerging young. Finally, Fluke Tabs® (Aquarium Products, Glen Burnie MD) have also shown strong effect in warmer water at one tablet per ten gallons applied in two treatments 4 days apart.
Whilst, with enough determination, beating skin flukes is relatively easy, however, the same can't always be said for gill flukes. Because of gill hyperplasia and increased mucus, the gill-dwellers are often afforded a high degree of protection from chemical treatments.
The most important step in preventing a serious fluke or indeed any parasite problem is first to investigate abnormal behaviour - that is incessant rubbing and flashing or lethargy. Don't just say "parasites" and dump some chemical into the water. It is important to know what you're dealing with and how severe the problem is. In severe cases it is important to do a follow up at the end of the treatment to see how effective it has been.
HTH
Les
