gourami color change/dying

Question
QUESTION: Dear Chris,
I have an established tank.  The pH, nitrite and amonia all read ideal.  I had a
yellow gourami recently lose it's color and then die.  Now my pigmy gourami is
quite pale and seems to be more shy.  I have 2 newer gouramis which are so far
ok.  Any suggestions?

ANSWER: Hi Kay;

There area several possibilities. It's really hard to say why a fish died if there are no other indications besides fading color.

The pygmy may be reacting to the new fish and it may not be related to the first death at all. If the new ones are bigger he could be getting bullied or just scared. Here are other things to look for;

Do their bellies look swollen when they get faded? Dropsy or constipation are possible.

Do you have at least one female per male? Gourami males can be very territorial and become quite aggressive with each other. Even if other fish don't look injured, they can become stressed enough to actually die.

Is the tank large enough? Gouramis need plenty of space to hide and for each pair or male to have territory of their own. The larger types such as golds, three-spot and opaline need at least 20 gallons because they get so big. The dwarf types are okay in a 10 gallon but there should be no more than one male.

Are there any other signs of disease? Spots, dots, redness, usual coloration, unusual movement, hiding, gasping? There are many possible diseases it could be depending on the signs and symptoms. Let me know what you find, if anything.

At Your Service;
Chris Robbins

---------- FOLLOW-UP ----------

QUESTION: Chris,  Thanks for your reply.  As feared, the dwarf has now also died.  I
doubt this is a coincidence.  It too faded from yellow to white;hid;failed; died.
I have a 30 gal tank now with 3 silver dollars,2 gourami's(a flame and a blue
stripped) a picastamus, and another bottome dweller.  The first yellow one
gradually decreased color and MAYBE had raw looking areas.
How do I tell the sex?  The 2 remaining gouramis came from the same tank in
the store. I've never witnessed aggressive behavior from any of the fish. The
blue one is tending to be shy.  I just don't want to lose any more fish.
Thanks for your help.
Kay

ANSWER: Hi Kay;

OOPS!

I forgot to answer part of your question and gave the wrong name of the parasite in the last answer too. So sorry for falling down on the job!

The correct name of the parasite I mentioned is "Gyrodactylus" aka skin flukes. The other, "Dactylogyrus" is the gill fluke.

To sex the dwarf, gold, blue, three-spot, pearl and opaline gouramis, look at the dorsal fin. It is longer and pointed in the male as he matures. Adult males are also often brighter colored and thinner. Here is a good web page on it with a photo too;

http://freshaquarium.about.com/od/fishqa/f/faq2060.htm

At Your Service;
Chris Robbins

******************

Hi Kay;

Oh, that's a shame. I'm sorry you lost another one.

It could be a bacterial infection or even a parasite. If you noticed the sick ones "rocking" back and forth, I would suspect a parasite known as "skin flukes", aka "Dactylogyrus". It is also sometimes known as "Gourami Disease". Get a medicine from the fish store that specifically treats them.

If there was no abnormal swimming and just maybe raw looking areas, it was probably bacterial. I would use "Maracyn Two" in that case.

Aquarium salt and a natural product called "MelaFix" can both be used along with the other treatments too. The salt helps kill bacteria and parasites as well as giving the fish electrolytes to fight stress. Melafix helps heal wounds and soothe raw areas.

At Your Service;
Chris Robbins

---------- FOLLOW-UP ----------

QUESTION: Chris, thanks again.  I didn't notice any rocking back and forth and eventually
in the 1st fish there were probably rawish looking spots.  Could the bacterial
infection be gourami specific because the silver dollars are fine?  Also, the 2
reamaining gouramis came as the first became ill, but they look fine now.  
Should I treat the tank with Marcyn two and MelaFix preemptively or wait for
symptoms?
Kay

Answer
Hi Kay;

I'm really glad they weren't rocking. It's from a nasty parasite.

I might go ahead and use Maracyn two and Melafix if they were my fish. I don't usually recommend "preventive" use of antibiotics, but you have had some devastating losses. The disease seems pretty aggressive and a fast killer.

At Your Service;
Chris Robbins