Help identify black sludge-like growth growing on fins and scales of my predator haps [IMAGES]

[sawellem]

Have you tested your water?

Yes

If yes, what is your ammonia?

0

If yes, what is your nitrite?

0

If yes, what is your nitrate?

20

If I did not test my water...

...I recognize that I will likely be asked to do a test, and that water tests are critical for solving freshwater health problems.

Do you do water changes?

Yes

What percentage of water do you change?

61-70%

How frequently do you change your water?

Every week

If I do not change my water...

...I recognize that I will likely be recommended to do a water change, and water changes are critical for preventing future freshwater health problems.

[IMAGES BELOW]

Hello fish keepers,

I am in dire need of help identifying the disease found on the scales and fins of this large rostratus. It is characterized by a sludgy black growth that covers both scales and fins. The growth has thickened on the fishes fins to the point where it has lost much of the fins mobility. It also accumulates on the scales and as you can see, is maybe a couple millimeters thick in certain areas. I've tried researching this problem countless times without success. The disease that keeps popping up on google is black spot disease but I don't think that's it. Black spot disease seems to be small black spots while this grows in larger, sludge-like spots.

I've had the fish for almost a year now and have been concerned about this problem since I've had it. I wasn't able to come up with any answers to my questions, and LFS staff said it was just discoloration. This caused me to put the problem to the back of my mind, even though I knew it wasn't right. Flash forward to today, I was in my garage looking at the fish and pretty much yelled "F***" when I noticed all of my predator haps are starting to show early spots very similar to what the rostratus pictured has. Right now, my other haps just have small 1 cm large black spots growing on their skins and scales, but I can tell that it is the same problem afflicting the rostratus. I am really hoping someone will help me identify this problem, so that I can stop it in its tracks on my other fish. I have some beautiful fish, including an 8" Buccochromis Rhoadesii Yellow, and I really want to keep them healthy.

Please help me identify this disease! Has anyone seen this on any of their fish before? Any tips are welcome and appreciated!

Thanks so much for your help and time. Please have a look at the images below.

Best,
Sawellem

P.S: Fish lives in a 180g (40g sump) with other predator haps. Large 60-70% percent water changes once per week as they poop like monsters.

 

[sawellem]

The Buccochromis mentioned. You can actually see the black growth beginning to form 3/4 of the way down on his dorsal fin!

And my Livingstonii:

 

[kno4te]

Never seen that before. If one else has experienced this then i’d suggest dose prazipro with repeat dosing. If not better then a potassium permanganate bath but it’s risky with pp. Maybe duanes and Rocksor have seen this.

 

[Rocksor]

Never seen that before on my fish but I do remember a MFK thread about black spot disease

Unless your fish were exposed to the outdoors, the chances of them having black spot disease is slim to none. The disease is spread by birds, and carried by snails. In freshwater fish there is no real treatment, you have to simply wait it out & make sure that the cycle cannot repeat itself. (do not keep snails with infected fish)

The "Noga" mentioned in the excerpt below would be Dr. Edward J. Noga, MS, DVM, a highly respected professor of aquatic medicine and immunology, that has been published approx 150 times in related papers/journals. His lab at NC State University specializes in the study of infectious diseases of finfish and shellfish.

“According to Noga, if the fish has "black spot disease" there is no OTC treatment for the metacercaria (which are not in themselves lethal). They will simply "come out" of the cysts.

If there are no snails or copepods around, that is the end of the line. However, while the metacercaria are there, they can cause an immune reaction, which can be hard on the fish. If/when the metacercaria come out, they leave behind a hole that can get infected with bacteria and/or bleed. That is a danger to the fish. Salt in the water helps healing and increases production of the slime coat. Frequent water changes dilute out any possible infectious bacteria and supports the immune system. The key for fish survival (if they do not bleed to death from the holes) is a good immune system.

Black Spot is due to the metacercarian stage of a parasite with a complex life cycle called a "digenean" trematode . The "black spot" is caused by the metacercaria encysted under the skin which irritates the melanocytes of the fish tissue, causing the dark spot.

As long as it is under the skin, it is impervious from outside.”

 

[sawellem]

Thank you kno4te and Rocksor for your replies.

Rocksor— thank you for the info on black spot disease. It kind of reinforces my thoughts that this isn't the problem. I do have pest snails in my tank, but they were introduced at least 6 months after the fish was living with this problem. Also, because the problem is an irritation under the skin that causes melatonin changes, and my fish has the growth fully covering scales and fins, I don't think that is it.

It is nice to know I'm not alone in never having seen this before. I can't even find an image on google of a fish with similar symptoms.

Someone over on ThePlantedTank.net suggested a protozoan infection with possible secondary bacterial/fungal infection. This goes along the lines of what kno4te suggested with PraziPro and I think it's worth a shot. After looking at some of the common Protozoan / Ciliates infections in fish, I am leaning more towards a Protozoan related issue, but I really don't know enough to be certain.

Also, by any chance, would this issue be related to swim bladder disorder? I have about ~12 haps in my aquarium. Three months ago, my dominant Rostratus (not pictured) got Swim Bladder disorder and I was unable to cure it with either Epsom Salt or General Cure. Sadly, had to euthanize him (clove oil) after he refused to eat for months and it became clear he was just going to starve away. Last week, the rostratus (pictured) also got swim bladder disorder and is not responding to treatment. Feeling like I am losing control of the health of my fish is what motivated me to make this post about the spreading black smudge issue. Both of the rostratus with swim bladder disorder had the black smudge (although my dominant male had it much less) and are the only fish to be sick with any kind of problem since having the tank for almost two years.

Thanks again, appreciate the help.

Best,
Sawellem

 

[kno4te]

Hard to say if this is related to swim bladder. But protozoans can infect and affect a swim bladder. This seems to be something else all together but will see how it responds to the prazipro.