jack dempsey with possible internal parasites

Question
QUESTION: I have a 90 gal. tank and my water readings are ammonia 0, nitrites 0, nitrates between 5-10 and ph around 7.8.  I have had my jack dempsey for about 2-3 years now and he's about 8 inches long. Last week he started darting around the tank like a maniac, banging into the decor, the tank walls and even almost banging right out of the top. He has been doing this several times a day and has even caused injury to himself because he is quite scraped up. He usually finishes this outburst by burrowing head first into the gravel and staying there like that for several minutes. When he does this he appears to be gasping for breath. The other fish all stay in a small area of the tank while he does this. In between outbursts he has been hiding in a tree stump. He still eats but not at every feeding anymore. Sometimes when he swims in a regular fashion he tilts and may even go upside down. Could this be internal parasites??

ANSWER: Hi Amanda,
  You need to do more water changes.  I would do a 25% water change today, then again tommorrow and then again the next day.  Although your readings are good, this kind of behavior is very typical of a fish in poor water.  

  You should be changing 25% of his water once a week, every week to keep him healthy.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>


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

QUESTION: Hi Ron,
Thanks for replying. I do a 35% water change every 2 weeks without fail. I don't see how this can be linked to poor water conditions. If you don't think it could be internal parasites then do you have maybe any other ideas?

Answer
Hi Amanda,
 The connection is that higher levels of nitrogen in the water make fish do the "darting" behavior you describe.  However, if you are changing 35% every other week, that shouldn't be a problem, assuming that you are not overfeeding your fish.  I assume also that there aren't any "missing" fish that are in fact rotting under a lot or something like that.  Dead catfish in particular can foul the water way out of proportion to their size.  I have had single small catfish kill entire tanks when they died.

  I can't rule out internal parasites but if it were intestinal parasites he wouldn't likely be eating at all.  Also, he would likely have white, stringy feces. If it were a brain parasite there is nothing that you can do about it that I know of.
Similarly if it were neurological damage (which sometimes causes spiraling behavior) there is nothing you can do about that.

 The one other possible cause would be if another large fish really banged him hard, causing permanent internal damage.  Large cichlids are capable of doing this (even, unfortunately killing other fish with one shot) but you didn't mention other large cichlids in the tank so I assume that isn't the case.  

 So, that's why I ended up with water quality as both a possible explanation and something that could potentially be changed for the better.  

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>