Oodinium - Velvet (was Re: Aplocheilichthys spilauchen)

[whuntley]

A few comments from the peanut gallery.

Brackish Lampeyes can often be kept in fresh water, but they will not usually breed successfully, there.

Velvet affects almost any species of fresh-water fishes and many salt-water ones. It is usually from an infection of the parasitic skin, gill and intestinal flagellate *Oodinium pillularis*. Salt-water species usually get *Oodimium ocellatum*. While Nothos are considered more susceptible than others, I have seen it in almost all genera of killifish, at one time or another.

Treatment is easy, and salt is a pretty good preventative, if the initial water is hard enough. [Don't try it if you don't have at least a GH of 3-4 degrees, though.]

I have had good cure results with combinations of elevated temperature, salt, and acriflavin, coupled with increased water changes. I suspect flubendazole might be a great cure, but admit I have not tried it. [It seems to kill most invert parasites.]

"Velvet" is normally only slightly infectious and doesn't spread readily. That's why it hangs around in most tanks. I have encountered strains that were much more virulent, and that could wipe out a tank in a day or two,

After a lot of microscopic detective work, I have come to the conclusion that sudden mysterious die-off of whole batches small babies is, at least 90% of the time, an invisible velvet infection. [At about 100 microns, the free-swimming flagellates are very easy to spot with a modest-power microscope.]

HTH. Remember, free advice is worth every penny.

Wright

[stormhawk]

Wright, thanks for the advice. Its worth every penny coming from you :wink: I've not had any problems with velvet yet so hopefully it doesn't appear. *touch wood*

[Slaigar]

That is very helpful information. Just to verify, a little salt is more beneficial when combined with hard water?

For the lampeyes, I am still trying to think how to set up a tank for them. Brackish seems out of my way as I am mostly into aquatic plants. Most of the plants that can live in brackish waters are just not that interesting!

[timebomb]

Wright,

I'll be the last person to disagree with you but from my limited experiences with Velvet, I find it to be a very infectious disease. The moment it appears on one of my Nothos, it will invariably spread to all the others. The rate of infection is slow but eventually, every other Notho gets it.

Left untreated, the fish never recovers from Velvet disease. This is quite unlike my experiences with Ich which quite often disappears from the fish even though I didn't add any medication.

I can't claim to have kept many species of tropical fish but I've in the hobby for more than 30 years. I encountered Velvet only when I started keeping Killies. I have not seen other Killies other than the Nothos get infected with Velvet. Aphyosemion australes, as far as I know, are prone to Ich. I've kept them in the same tank with Nothos infected with Velvet but the australes seem to be invulnerable to the Velvet parasite. I have tried many brands of fish medication but there's only a limited number of medications that are used to treat velvet. To treat Ich however, there are plenty. Many fish shop owners also have never seen Velvet disease before but they all know about Ich. I'm stating these facts because they help to verify that my theory about Velvet infecting only certain fish is true.

Having said all that, I have to say too that I have the greatest respect for Wright's knowledge on fish and fish diseases. If he says every genus of fish can get Velvet disease, I will accept that to be correct too. It's just that my own experiences seem to indicate otherwise.

Loh K L

[whuntley]

[quote="Slaigar"]That is very helpful information. Just to verify, a little salt is more beneficial when combined with hard water?

No, a little salt can be quite toxic if there are missing essential blood electrolytes, like Ca, K and Mg. It can be quite safe, if those electrolytes are there in the water in sufficient quantity.

I only discovered this when I killed most of my plants and made my fish sick after moving to Modesto, at the foot of the Sierra-Nevada mountains, a couple of years ago. The snow runoff was about 30 ppm tds, and most of that was as silica, as it had been exposed only to granite. GH was immeasureably low. I tried to raise tds (to lower osmotic stress) by adding salt, and even my brackish-tolerant plants, like Java Moss and Java Fern turned brown!

When I replaced the essential electrolytes, by adding some Seachem "Equilibrium," they bounced right back. Since then, I have looked back on many incidents, mostly among discus and other SA (Amazonian) enthusiasts who were constantly stressing their fish by using pure RO water without any reconstitution. [Their purchases of meds was the delight of the LFS. ]

As I understand it (I'm an engineer, not a physiologist) transport across cell walls uses Na+, K+, Ca++, Mg++ and other essential ions to effect exchanges. Cell metabolism is seriously hurt if they are not present, at all, and Na+ seems particularly damaging if not accompanied by the others.

Bottom line is to be very cautious about adding salt if your water is essentially soft to start. Be double careful about adding it to DI or RO water. It can even kill.

Wright

[whuntley]

Wright,

I'll be the last person to disagree with you but from my limited experiences with Velvet, I find it to be a very infectious disease. The moment it appears on one of my Nothos, it will invariably spread to all the others. The rate of infection is slow but eventually, every other Notho gets it.

Left untreated, the fish never recovers from Velvet disease. This is quite unlike my experiences with Ich which quite often disappears from the fish even though I didn't add any medication.

I can't claim to have kept many species of tropical fish but I've in the hobby for more than 30 years. I encountered Velvet only when I started keeping Killies. I have not seen other Killies other than the Nothos get infected with Velvet. Aphyosemion australes, as far as I know, are prone to Ich. I've kept them in the same tank with Nothos infected with Velvet but the australes seem to be invulnerable to the Velvet parasite. I have tried many brands of fish medication but there's only a limited number of medications that are used to treat velvet. To treat Ich however, there are plenty. Many fish shop owners also have never seen Velvet disease before but they all know about Ich. I'm stating these facts because they help to verify that my theory about Velvet infecting only certain fish is true.

Having said all that, I have to say too that I have the greatest respect for Wright's knowledge on fish and fish diseases. If he says every genus of fish can get Velvet disease, I will accept that to be correct too. It's just that my own experiences seem to indicate otherwise.

Loh K L

Our difference in experience is likely due to the temperature sensitivity of most Velvet organisms. They don't seem to like heat, and that is one common cure method. I would guess your tanks average a bit warmer than mine. Costia species cannot tolerate over 30 degrees C, but my references don't give a number for other Velvet-like organisms.

Many common shop fish can carry velvet with no external symptoms, but exposing sensitive fish (like Nothos) can cause an outbreak.

Since most deaths from Oodimium species (the common Velvet genus) are caused by gill and internal damage, you will never see it without a microscopic necropsy. [Use a 100X view the next time you see clamped fins and gasping at the surface. You might be surprised at what's growing on the gills.] Only Nothos and other high metabolism fishes seem to ever get the characteristic skin-dusting form of it, unless it is brought out by sudden cell stress, like osmotic shock or chlorine poisoning. Then it develops more quickly and may show on the surface before killing the host.

Velvet can be caused my numerous parasites, and I think the level of infectiousness is dependent on the strain, and on the recent stresses on the fish. IME, it varies quite a bit. I got one infection from some African eggs that ran through several tanks rather quickly, killing fish en mass.

Usually it is a much slower killer, and that treatment opportunity stops it cold.

That said, my experience is pretty limited because I don't see Velvet very often, either. Good husbandry and even inadequate water changes can keep stress low enough that it doesn't break out (at a symptom level) too often. [Mr. Loh's infrequent encounters speaks very well for his husbandry skills, I think.]

Wright

[RonWill]

Use a 100X view the next time you see clamped fins and gasping at the surface. You might be surprised at what's growing on the gills

Wright, average hobbyists will hardly get to work with a 100x scope, so what is it that'll greet us at the eyepiece? Oodinium* parasites? Is this what we'll be looking at?
*Oodinium (with one 'm')

Also, by "high metabolism fishes", would that cover all annuals or does it include non-annuals like australe as well?

I got one infection from some African eggs that ran through several tanks rather quickly, killing fish en mass.

Knowing how careful you usually are, can you expand on the incident? I can understand it if unquarantined fishes are introduced but cannot connect how eggs will spread the parasite to the rest of your fishes.

[whuntley]

Use a 100X view the next time you see clamped fins and gasping at the surface. You might be surprised at what's growing on the gills

Wright, average hobbyists will hardly get to work with a 100x scope, so what is it that'll greet us at the eyepiece? Oodinium* parasites? Is this what we'll be looking at?
*Oodinium (with one 'm')

Also, by "high metabolism fishes", would that cover all annuals or does it include non-annuals like australe as well?

I got one infection from some African eggs that ran through several tanks rather quickly, killing fish en mass.

Knowing how careful you usually are, can you expand on the incident? I can understand it if unquarantined fishes are introduced but cannot connect how eggs will spread the parasite to the rest of your fishes.

The link is great. I hadn't seen it before. It shows well, what to look for. Also see the Untergasser book, referenced there. Illustrations are only for those of strong stomach. You have been warned.

BTW, thanks for catching my bad early-morning spelling. Helps to look up the right thing, huh?

The free-swimming stage is short-lived, and rarely lasts 24 hours. In an active outbreak, transfer of tiny amounts of water containing flagellates can spread it. No, I'm not always as careful as I should be, and I rarely take any precautions about contagion until an outbreak is obvious. The one cited was way too virulent and fast-developing for me to get away with my usual casual movement of wet nets, etc.

Many organisms survive the damp-peat cycle, and can break out when the dormant cysts are exposed to the hatching water. Glugea anomala and Velvet are two that come to mind.

Lesson learned. I do like to use dry nets, now. Only Myco and a few other pathogens survive complete drying.

Long haul, I try to keep all my tanks equally infected with all the sub-lethal organisms, so I don't have to worry about fish with no immunity. Crude, but my medicine bills are very near zero, too.

I was thinking more of fresh-water Lampeyes when I suggested high-metabolism. I think AUS and many Fp. would be inclined to show it more than most other Aphyos, but that's just a guess. Paludopanchax and other Notho-related species like THI might be expected to get it more readily.

Wright

[RonWill]

Also see the Untergasser book, referenced there. Illustrations are only for those of strong stomach.

Wright, I've more links on Oodinium than I care to remember as this is a major killer in my tanks! It's extremely virulent and doesn't cut me any slack for treatment.

There's a 'low-price' $10.50 new copy of Dieter Untergasser's "Handbook of Fish diseases" at Amazon.com but my current reference* is adequate. Perhaps others here might want to buy it? (it lists for USD35)
* "Colorguide of tropical fish diseases" by Gerald Bassleer.

But I'll have to concur with Kwek Leong, in that non-killie species are less prone to Velvet. My initial acquaintance with this plague wiped clean my entire collection of nothos!

Whenever possible (or when I can remember), I'll go with separate nets and siphon attachments during water changes, to minimize disease cross-infection. I can only do so much, especially when I'm just as careless.

Many organisms survive the damp-peat cycle, and can break out when the dormant cysts are exposed to the hatching water. Glugea anomala and Velvet are two that come to mind.

Now, this is interesting... and just how is one suppose to 'quarantine' off this risk? What further precautions??

[stormhawk]

Ron,

The book is retailing at around SG$70+ at Kinokuniya. Maybe you'd like to get a copy. Pretty thick hardcover book. I may get a copy but not now.

Never had any experience with velvet so I can't say much. Have had problems with fungus and white spot. Dealt with white spot easily but had bad results with fungus. Lost a pair of wild bettas to a fungal infection. Even acriflavin didn't help.

[RonWill]

Jian Yang, tempting as it may be, I'll pass. If Wright says it's good, then hopefully someone else here will catch on.

Wright, I'm editing the subject title to something more appropriate and making topic search easier.

[whuntley]

Many organisms survive the damp-peat cycle, and can break out when the dormant cysts are exposed to the hatching water. Glugea anomala and Velvet are two that come to mind.

Now, this is interesting... and just how is one suppose to 'quarantine' off this risk? What further precautions??

I have heard reports that getting new hatchlings off the peat quickly can stop the Glugea outbreak, by removing them before the cysts can hatch. That's something I never tried. I think Barry Cooper and others have some treatments now that are more conventional.

For Velvet, the usual stuff can keep the organisms under control. Use harder water, add some salt (and maybe a drop of acriflavin), and be sure all food is eaten or removed. Clean water is easier to get with a few snails to clean up any left-over bbs.

I'm not certain it is reasonable to expect no Oodinium organisms are present, but clean water, healthy undamaged fish, and otherwise good environment usually prevents serious outbreaks. By letting the parasite weed out the few with poor immunity, it may actually make our fish stronger, long haul.

This, of course, doesn't apply to an unusually virulent strain. For that, quarantine and sterilization are about the only way to go.

Another usually mild infection, Cottonmouth Disease, (Flexibacter columnaris) can come in chronic and acute forms. The former can be treated over several days but the latter can wipe out a tank in a few hours. Again, good water conditions give time to react, while poor water can speed the disease. Heat speeds the infection, in this case. [BTW, this disease is often confused with fungus, and it is not a fungus. Fungus only grows on already dead tissue, so is almost never a primary disease.]

Wright

PS. Thanks Ronnie for fixing the subject. I'm a novice at forums, and have felt a bit like a bull in a china shop in here. :wink: