If there was one thing I could completely eradicate from the fishkeeping world, it would be this pesky parasite. If you trawl back through this blog, you will see velvet is unequivocally, the bane of my entire fishkeeping existence. I simply cannot understand why when on one hand I can have such incredible success with keeping and breeding these fish, and then on the other hand, have to continue to have this parasite plague my tanks.
Anyone who has seen my fish in person, knows that they are the vision of good health. Apart from the odd missing scale or torn fin, they are always spectacularly coloured (can be a challenge with this complex), active, and brimming with vigour. It doesn't seem likely that the cause for this problem lies with my water conditions. Surely, if they were incompatible with keeping these species, I would not be able to coax as many successful spawns as I have out of my breeding pairs. Compared to some breeders who may struggle with this complex, it's not unusual for my pairs to spawn up to twice a week for month after month with resulting fry thriving. Surely, if it was my water that was the problem, I would not have such resounding success?
At the end of last year, I finally got rid of velvet out of all my tanks through treatment, culling, and disinfection. Only one group of fish had been previously affected by the parasite at that point, and they were kept properly isolated from the rest. I was meticulous in ensuring that there was no possible cross-contamination going on, but still, after months of actually being able to enjoy the hobby again, velvet was back in my fish room with a vengeance.
There seems no rhyme or reason as to why it shows up in some tanks and not others. I thought perhaps stress due to aggression was the biggest contributing factor, but I have tanks that house some highly aggressive individuals and they have avoided being infected. Is it just some individuals have a weaker immune system than others and even a small amount of stress is enough to cause an infection? Or is it that particular individuals are more susceptible than others?
One difficulty, is making sure I pick up an infection early enough that I avoid spreading it to other tanks. Early on, it can be very hard to diagnose. Normally the first thing I notice is a change in behaviour: my fish will hide more or clamp their fins. Signs of visible irritation are usually quick to follow, and if I use a bright torch, I will start to see the tell-tale spots on the pectoral fins and the grey/gold dust starting to cover the body. I try my best not to share anything between tanks, but I am only human and it just takes one lapse in concentration for me to have spread the parasite from one tank to another.
I often think that my continued postings on this topic makes me sound like a piss poor fishkeeper. Constantly dealing with sick fish certainly makes me feel like one. But I've never faced this issue with any other species of fish I've kept. At this point, I've kept everything from Australian natives to guppies, and it seems that velvet only chooses to run riot through my wild betta tanks. I just wish I knew the root cause of these outbreaks so that I could address it. It is a horrible feeling to watch your fish sicken and suffer when you have no idea how to prevent it from happening.
Hailing from Melbourne, Australia, I currently keep and breed a number of species from the coccina complex.