Illness, – black coloration of fins

Hi Helene,

I´m not an expert with diseases but I remembered a thread in the IGL forum in the
Paradiesfisch section. Some Macropodus spechti were showing dark spots on fins and
body.
The reason was identified by Charly Roßmann to be organic material like
rotting leaves,- wood,- plants and lot of detritus(don´t know if it´s the right english word = Mulm) that pollutes the water and can cause this spots.

The author of the thread found the source a rotting peace of wood and changed regularly 50%
of the water and the spots were more or less gone.

Here is the link, maybe you can compare the symptoms and it might help.
IGL thread

Volker

Helene

Perhaps its just accumulations of natural pigmentation (melanin). Appearances of what seems un natural colouration can be common and in some cases aesthetically pleasing eg .Black Angel fish. The appearance in a number of related fishes could be due to a genetic marker (same with the malputta – and perhaps its a coincidence) but what triggers this I dont know ..I guess there could be a lot causes and one of those could be environmental… But at the end of the day if the fish are healthy I perhaps would not worry to much about it.

It is wrong to say “decay is dangerous”, but it is right to say “decay could be dangerous”.
I cannot comment on Helene’s problem; I don’t know what the cause of the black zones in the bodies of her fish are. But too much decay of rotting organic material can lead to such phenomena.
And certainly it can lead to severe hygienic problems.
This is one of the problems of blackwater aquaria, especially if they are small: You have to use much organic material (wood, leaves) which will not stay stable but undergo a process of continuing decay. Therefore, one has sharply to distinguish between fresh organic material and decaying organic material. And you have to consider the volume of a tank. The smaller your tanks are, it is certainly the more important to consider that problem.
If you begin a new small Parosphromenus-tank with leaves and wood, you should take fresh dead leaves and not too old wood. For instance, I take one sea-almond-tree leave and a handful of beech-leaves and some dead wood from a pet bog in a fresh set-up 10-liter-tank. This will have a good influence on it’s hygienic status for about at least four, maybe eight weeks. The sea-almond-tree-leaves are the first to rot, and then the positive influence turns into a negative. If it becomes smeary and greasy (and it will after some time), you should take it out and put a fresh in instead. The same happens with the beech leaves, but their decay takes more time, maybe months. Finally they have to be changed for new, too. It is very difficult to assess the decaying rate of wood, since there are very different forms and states of wood. Fresh dead wood from a peat bog is best, it will help you to create a stable blackwater milieu for months, maybe a year or even two. But the time will come when you have to throw it out and take a new one.
I admit that often I do not act in accordance with those rules. I had never that black spot problems, but I often had other problems (mostly fish disease, e.g. Oodinium and algae), telling me that some of my organic material has become too old and is rotting in a too-small tank. Then it is high time for a change.
Therefore, because we work with materials that are not normed but of very different natural origin, it is impossible to give a clear rule by quantitative measures. But one has certainly to consider the qualitative relations. Every dead organic material rots, but in different amounts of time. And all rotting is a load for a (small) tank. The beginning of that rotting process will have a positive influence on the blackwater milieu. But one has to learn when the point of a turnover has come; and act.

I have one female nagyi that has black marks on her dorsal, and a few black marks on her upper body and one on her tail.
It looks like random melanistic blotches, black coloration with no texture. Most of it is on the dorsal, several blotches. The tail has two smaller blotches.
There are two males with her, I saw black splotches on the tail of one of them, it is showing breeding color and acting fairly normal, still has the splotches though. The other male is hidden in a cave and I can’t see him.
I don’t think the other separate tank which has one pair in it is infected, or hasn’t shown it on the fish yet.
Any treatment, other than water changes and cleaning out rotting material, to try?
If the fish stays the same with these markings on it, is it likely that it will still reproduce and if it does is there some health problem passed on to the offspring?
It’s probably a matter of time whether or not it improves on its own, gets worse, is contagious, etc.
This tank does have a snail problem, and has had live blackworms as food.
If the disease is black spot, snails are said to be part of the life cycle of the parasite.
If it is environmental, caused by rotting material in the tank, maybe it should then clear up with improved conditions.
Copper sulphate is mentioned as a treatment for black spot, but that would probably be dangerous wouldn’t it.
Maybe salt or flubendazole works, I’m using flubendazole soon anyway for hydra.