new tang develops white spot

[ryan scott]

I have always seen the odd spot on my blue tang but never gotten out of control.

The rest of the fish are still fine and the tank is responding well
so just have to wait and see as i cant fit all of my fish in qt

[capn_hylinur]

Originally posted by dclaghorn
my LFS says that all wild-caught fish have it. It's just inherent, with cysts essentially hanging out in the fish's mucus until a period of stress arises. This is why some fish, like the tangs - which are easily stressed, are more prone to it. Their immune systems just can't keep it at bay. Makes sense to me.

beware of generalizations esp anecdotal ones------ I find this very hard to believe.
maybe some of our marine biologists here can comment on this one.

[GoingPostal]

Everything I've read indicates ich is quite rare and not a problem in the ocean.

[cmejaf30]

Originally posted by GoingPostal
Everything I've read indicates ich is quite rare and not a problem in the ocean.

I agree with this. All research that I've done on Ich brings me to believe that although it is present in the ocean, the chance of it becoming a problem on any reef is very rare. Think about the probability that any of the tomites (free swimming stage of the life cycle) find a host is very slim. However, shrink that ocean reef down to about 125gallons or so and the probability becomes very great. Once you take care of the parasite in your system you will not introduce it again unless brought in by another fish. Inverts won't carry it and neither will corals (although you should QT anyways). Just some food for thought.

[Ninong]

Originally posted by dclaghorn
my LFS says that all wild-caught fish have it.

This claim is untrue but I can understand why it may be popular with some LFS personnel.

It's just inherent, with cysts essentially hanging out in the fish's mucus until a period of stress arises.

The cysts (tomonts) are never attached to the fish. Trophonts are attached to the fish and they don't "hang out in the mucus," they burrow deeply into the epithelium. The cysts (tomonts) are the reproductive stage that develops after the mature trophonts have disassociated from the host. Stress doesn't cause ich, although it may lower a fish's resistance to infection.

[cdbias2]

This always gets people miffed when they hear this but, my sons tank got a terrible outbreak if Ich twice, two weeks apart, from adding a only one pound of sand/grunge that was ordered online and had a chance to cool way down during shipping.
I say Ich lives in the sand also, is always present, and it just waits on a stress factor to hatch and attach to fish.

[cmejaf30]

Originally posted by cdbias2
This always gets people miffed when they hear this but, my sons tank got a terrible outbreak if Ich twice, two weeks apart, from adding a only one pound of sand/grunge that was ordered online and had a chance to cool way down during shipping.
I say Ich lives in the sand also, is always present, and it just waits on a stress factor to hatch and attach to fish.

Untrue. While the troponent phase may last as long as 5weeks, it never just "sits and waits." It has a life cycle just like every other living organism and in that time period, if (when it hatches and becomes a tomite) it can't find a fish to host on, it will surely die. It won't swim back down to the sand, build a castle, and wait vigilantly for a weak fish to swim by.

[Freed]

I concur...r

[cdbias2]

Twice!

[dclaghorn]

So really, that wait six weeks will be a pretty good period of time for even the trophots to die off for lack of a host? In the sand? What I believe was my precipitating event was after I brought in two gold striped maroon clowns, a powder brown and yellow tang, I completely stirred up the sand bed trying to get algae from the glass beneath the level of the substrate. Two days later, fish started succumbing. The powder brown was the first to go.

Started using the 5-nitroimidazole in the tank, after reading the Captain's suggested reading, but now only one fishy left. Need QT to get him out. Then, I guess, the waiting just begins. Don't know if I want a whole 29 (that LFS wants to sell me - but not the usual guy, Rusty, who is way smart about reefs). But 10 may be too small to QT a decent sized, say, 4" fish or two... Thoughts?

Thanks,
Dave

[Freed]

Read my interests. I always QT after bringing home any and every fish and the only place I have ever seen ich on any of my fish has been in QT after a week or so. After hypo I have never had any ich in the main tanks.

[Ninong]

Originally posted by cmejaf30
Untrue. While the troponent phase may last as long as 5weeks, it never just "sits and waits." It has a life cycle just like every other living organism and in that time period, if (when it hatches and becomes a tomite) it can't find a fish to host on, it will surely die. It won't swim back down to the sand, build a castle, and wait vigilantly for a weak fish to swim by.

You're on the right track here but you're confusing the issue because what you are really talking about is the tomont stage, not the trophont stage.

The trophont stage is the stage that is attached to the fish and it lasts no more than three to seven days.

The tomont (cyst) state is the reproductive stage and it usually lasts around a week but this can vary from three days to 28 days.

[Ninong]

Originally posted by dclaghorn
So really, that wait six weeks will be a pretty good period of time for even the trophots to die off for lack of a host? In the sand?

Change that to tomonts and it will be correct. Their peak activity is between 4-8 days but can be as short as 3 days or as long as 28 days depending on temperature. The warmer the temperature, the shorter the incubation period.

[cmejaf30]

Originally posted by Ninong
You're on the right track here but you're confusing the issue because what you are really talking about is the tomont stage, not the trophont stage.

The trophont stage is the stage that is attached to the fish and it lasts no more than three to seven days.

The tomont (cyst) state is the reproductive stage and it usually lasts around a week but this can vary from three days to 28 days.

my bad...you are correct!

[capn_hylinur]

Originally posted by Ninong
Change that to tomonts and it will be correct. Their peak activity is between 4-8 days but can be as short as 3 days or as long as 28 days depending on temperature. The warmer the temperature, the shorter the incubation period.

and this is the basic premise behind quarantining and observing for 4- 6 weeks. In the tomont stage the bacteria leaves the host, and the host appears to have kicked the ich, only to have an outbreak later again.

[Ninong]

Let's review:

Tomont (cyst) stage usually lasts approximately one week but can be as short as 3 days or as long as 28 days. At the end of this reproductive stage, up to 200 tomites excyst. These can develop into free swimming theronts. The theronts are only viable for 24-48 hours, sometimes less. If they can't find a host fish to attach to during that time they die.

The theronts attach to the fish and become trophonts. They burrow deep into the epithelium and grow in size. This stage lasts from 3-7 days.

Mature trophonts fall off the fish (usually at night). This stage can be free swimming or they can simply drift straight to the substrate. This stage lasts up to 18 hours before encystment as tomonts.

The tomonts (cysts) are the reproductive stage that usually lasts about one week but can be as short as 3 days or as long as 28 days. The cyst opens releasing up to 200 tomites which are capable of becoming free swimming theronts. Excystment happens at night.

[Ninong]

Originally posted by capn_hylinur
and this is the basic premise behind quarantining and observing for 4- 6 weeks. In the tomont stage the bacteria leaves the host, and the host appears to have kicked the ich, only to have an outbreak later again.

Except that it's not a bacterium, it's a ciliated protozoan.

[capn_hylinur]

Originally posted by dclaghorn
So really, that wait six weeks will be a pretty good period of time for even the trophots to die off for lack of a host? In the sand? What I believe was my precipitating event was after I brought in two gold striped maroon clowns, a powder brown and yellow tang, I completely stirred up the sand bed trying to get algae from the glass beneath the level of the substrate. Two days later, fish started succumbing. The powder brown was the first to go.

Started using the 5-nitroimidazole in the tank, after reading the Captain's suggested reading, but now only one fishy left. Need QT to get him out. Then, I guess, the waiting just begins. Don't know if I want a whole 29 (that LFS wants to sell me - but not the usual guy, Rusty, who is way smart about reefs). But 10 may be too small to QT a decent sized, say, 4" fish or two... Thoughts?

Thanks,
Dave

I believe that article favoured hyposalinity as a preferred method.
Personally I leave chemicals and medications as last resorts after all natural methods have been tried.

[capn_hylinur]

Originally posted by Ninong
Except that it's not a bacterium, it's a ciliated protozoan.

thanks Ninong---you are so right--can't believe I wrote that

[Freed]

Hypo is soooo much easier to do. Get your salinity down to 1.009 and make a mark on your tank at that water level, then all you have to do is top off to that same level a couple of times a day and check your salinity every day or two and you are all set. Sooo easy it's... priceless!!!

[Ninong]

Originally posted by Freed
Hypo is soooo much easier to do. Get your salinity down to 1.009 and make a mark on your tank at that water level, then all you have to do is top off to that same level a couple of times a day and check your salinity every day or two and you are all set. Sooo easy it's... priceless!!!

And it's much, much easier on the fish. Most fish can tolerate hyposalinity without problems as long as it's done properly. Take your time lowering the salinity over a period of several hours but take even longer raising it (a few days).

Copper has been proven to have long-term deleterious effects on the immune system and reproductive system, which is why many authors (e.g., Scott Michael) no longer recommend it.

[Freed]

Also with copper you have to test...test some more...add copper...test...add...buy more copper...test...etc,etc.

[Ninong]

Originally posted by dclaghorn
my LFS says that all wild-caught fish have it.

It may be correct that most fish in some LFS have ich because they may have added an infected fish to a holding tank with other uninfected fish, spreading the infestation. Without naming names, I can tell you that I have observed ich on most of the marine fish I have seen at a certain national pet store chain that it not known for proper husbandry of marine fish.

However, it is certainly possible to find fish available for sale that are not infected with ich. It is not ubiquitous in the wild. Studies have shown that the incidence of Cryptocaryon irritans varies and even in areas where it is more common, the parasite loads are small and not all fish are infected.

It may be geographically related because the incidence of C. irritans appears to vary widely with some studies showing very few, if any, infected fish and other studies showing low levels of infestation to be fairly common.

Study finding few, if any, infected fish in Puerto Rico: Bunkley-Williams L. and Williams E.H. 1994. Disease caused by Trichodina spheroidesi and Cryptocaryon irritans (Ciliophora) in wild coral reef fishes. Journal of Aquatic Animal Health 6:360-361.

Diggles and Lester found low levels of infestation were fairly common in southern Queensland:

Diggles B.K. and Lester R.J. 1996. Influence of temperature and host species on the development of Cryptocaryon irritans. J Parasitol 82:45-51.

Diggles B.K. and Lester R.J. 1996. Variation in the development of two isolates of Cryptocaryon irritans. J Parasitol 82:384-388.

There are older studies that also seem to confirm that distribution varies geographically.

[cdbias2]

I didn't read where ich only lives on fish.
Is it possible for it to live on/in microstars and micro organisms in your sand bed? I think it can.

Better yet, I'll give this another go around----
Should you QT live sand that is out of another tank?

[Freed]

Ich cannot feed off of anything other than fish BUT it can come in on anything WET. You should QT everything before putting it into the main tank although you don't medicate or perform hypo. The ich will die on its own in 4-6 weeks if you QT without fish.