Green Reef Chromis

[audiophile42]

I purchased 3 green reef chromis a little over 3 weeks ago. They've been in a 20g QT tank since then. One died after about a week - it wasn't eating much and I noticed it was getting bullied quite a bit by the others. The other two have been very active little pigs, always ready to eat NLS flake. About a week and a half ago I noticed something on one of them.

Sorry for the poor pictures, fast fish and simple point and shoot camera. It's a red mark about halfway down the side. Is the sign of a disease/parasite? Or is it just a cut/abrasion?

 

[JHemdal]

It could the start of red-band disease that green chromis frequently get. I have an article coming out about this in Aquarium Fish International, but I'm not sure when (I sent it to them almost a year ago).

The casuative organism is Uronema, that can live inside the tissues of the fish, so most topical medications won't help. I did some preliminary work using Chloroquine at 15 to 20ppm, but this has a deleterious effect on the bio-filter of aquariums. Uronema is most common in fish that are undergoing hyposalinity treatments.

Hopefully your fish has something else.


Jay

 

[audiophile42]

Thanks for the response. I was in a LFS (not the one I bought these fish from) that had several chromis with similar red marks, albeit more severe.

So is this deadly, or there a chance he could make it? Is it contagious, so the other fish in QT probably has it? Is there anything I can do besides try to keep good water quality? It's been almost 4 weeks in QT. I don't want to put them in the display tank if it could risk getting the other fish sick, but at the same time I want to start putting other fish through the QT process so I can get the display stocked more.

 

[mr.wilson]

The bacterial infection Vibrio anguillarum is also common with green chromis, as they are invariably overcrowded in wholesale and retail holding tanks. They look cool in a big group, but in a closed system during shipping & acclimation stress, disease transmission is common. Once I started keeping only five or six together instead of 50 or 60, the red marks and rapid mortality rate ceased. If the fish has raid breathing it would confirm vibrio, but this may be true of red band disease as well.

Since red band doesn't appear to be easily treated, go with what you can cure (vibrio). Add 250 mg/gal neomycin and 50mg/gal chloramphenicol in a hospital tank. Treat for 5 days medicating three times.

Alternatively, to keep water conditions optimum and reduce stress, you could give the fish a 20 minute bath in saltwater with 2500mg/gal nifurpironol which is 10 times the normal dose, then return it to the display tank. You could paint an oxidizing agent like potassium permanganate on the wound but only in the very early stages of the disease.

 

[JHemdal]

mr. wilson,

Yes - rapid breathing is a hallmark of end-stage Uronema infections in green chromis. They usually die with the "open mouth" issue....like Mr. Bill on the old SNL show.

Vibrio and Uronema are often concurrent. It is a classic, what comes first, the checken of the egg. However, Vibrio can be isolated from almost any aquarium, so it is presumed to be secondary to the lesions caused by Uronema as it erupts on the skin of the fish. Prior to the gross visual skin lesions, there is no real symptom for Uronema. Once it erupts on the surface, you can isolate bacteria from the lesion, but IMO this is secondary. Here is a section from my upcoming article where I discuss this (Shsssh - don't tell the publisher!):

"While Vibrio is capable of causing lesions on its own, these seem to form beginning at the surface of the fish's skin, penetrating deeper into the fish's tissue as opposed to working from the inside out as with Uronema. Additionally, Vibrio lesions usually have a distinct edge around them, sometimes of a lighter color, that is always lacking in Uronema lesions. "


Ironically, the term "red band disease" was coined by somebody who presumed that the lesions were bruises caused by the frame of a net hitting the fish's body while it was being captured. Too bad they didn't take the time to do a skin scrape and see what the causative organism was!

Jay

 

[mr.wilson]

Thanks for the new info Jay. I will definitely pick up your book when it comes out, keep me posted. All of my resource books (Kingsford, Untergasser, Herwig, Spotte) are over 20 years old. Surely we learned something along the way Do you have anything on newer generation antibiotic efficacy in your book. I always thought it was strange that fish get first and second generation meds while mere humans get the latest high priced versions.

You are right, the infamous red marks on the sides of green chromis do not have the raised white edge you attribute to vibrio. Most people in the aquarium trade just shrug it off as missing scales or bruises from physical abrasion during collection, subsequent handling and or aggressive tank mates.

It looks like it was Uronema all along. What I liked about the disease is that only one or two fish in the tank were showing symptoms at any one time. They would have a quick decline after three or four days with a death scene starting at the top of the tank in the corner with rapid breathing as they were seperated from the "herd", ending on the bottom with the famous last words. The open mouth as I removed the dead ones from the bottom of the tank was like one last cry for help. Maybe they were saying "UUUUrroooo..." as their last words. I was just to busy to listen

The seemingly "one at a time" infection rate gave me time to segregate them and try various treatments, or at least isolation. I can't say I had any sweeping success curing infected fish, but I did often see a halt in the transmission to other fish in the tank. One thing I can say for sure, is that cases of the disease basically disappeared after I started spreading them out with only a few in each tank. Not so good for merchandising, but great for quality assurance and loss prevention.

Do you have any insight into the causative agent in the death of lionfish with the same open mouth upon mortality? They rarely showed any signs of disease, then the next day I would find one or two (of 10 or 20 in my care) dead with the mouth gaped open. It seemed to be more common with newly arrived fish that were well fed. As much as I wanted to fatten them up and give them the food they had been lacking, they seemed to fare better being fed sparingly (usually freshwater feeder fish soaked in Selcon until I could convince them to take frozen silversides and shrimp).

 

[JHemdal]

mr. wilson,

Sorry - I haven't had any issues with lionfish lately - mostly because I haven't brought many in (grin). I have seen what you describe in newly imported fu-manchu and radiata lions a few years ago. I never did figure out what that was...didn't seem to be Uronema though.

Another characteristic of red band disease that I didn't mention is that the lesions tend to run along the scale line, so they often are angled front to back. They usually form mid-body, and often on both sides of the fish at the same time. Butterfly fish also get this fairly often. Uronema is a big problem with seahorses and seadragons, but the symptoms are totally different. I still firmly maintain that people will see more of this in fish that are kept in hyposalinity. Oddly enough, many web sites suggest that hypo is an effective treatment - but I've found that hypersalinity treatments (in sea dragons anyway) is actually a better treatment. I think that suggesting hypo is just an over-extrapolation, it works for another protozoan, Cryptocayon, so people just assume it will work for Uronema as well - but it doesn't.

Jay