Diagnose my sick fish

October 2, 2005 9:01 AM

What's wrong with my fish? I have a small orange fish. Not a goldfish, not a platy, but more than likely closely related to a platy. He normally has a narrow body, but for the past two days he's been very fat, his fins are "ruffled", and he's stressed, and hanging out at the bottom of the tank. I believe that he recently became a daddy and possibly feasted on his progeny.

I can't remember the name of his breed, but he's a dark orange with a little black stripe running the length of his body. He's a couple of centimetres long. He's lived happily for the past four months with a platy and two neon tetras in a five gallon aquarium.

A couple of weeks ago, I noticed that the platy was looking a little chubby and hypothesized that she was pregnant. Sure enough, a couple of days ago, there were a couple of orange specks swimming around in the water when I came home. The last time I saw one, it was being chased by a hungry looking tetra.

At the same time I first noticed the babies, I also noticed that this other fish (who my fry-inspired internet research revealed to be likely a male) was hanging around at the bottom of the tank and breathing hard. Over the past couple of days, he's gotten quite fat and his scales seem to be kind of standing up (the fins on his side look like the fur on an angry cat's back).

I don't think this fish is a platy as he doesn't look like the platy (not just markings, but body shape and different looking scales and different tail). I say this fish is more than likely closely related to a platy because he is the only real candidate for the fish-daddy. I had the pregnant platy long enough that I don't believe she could have arrived pregnant.

As far as ability to swim and to hold himself upright, he seems to be doing fine. He's swimming around near the bottom of the tank, not resting on the gravel. I just tried putting some food in the tank, and he didn't eat, but I think this is because he just never saw the food at the top.

My roommate suggests that he's freaked out because he wasn't ready to be a daddy. Does anyone have any other ideas on what could be wrong with him, and what if anything I could do to help?

posted by duck to pets & animals (8 comments total)

his scales seem to be kind of standing up

Ouch, that sounds like Dropsy, though I hope it's not.
posted by drezdn at 11:23 AM on October 2, 2005

I think very much that your little guy has dropsy. The big red flag for me is your description of his scales. There are lots of resources on the web (that link was just the first on google once you know the right words), and many things that might have caused his condition, although eating his babies is unlikely.

Best of luck, sick fish can be distressing.
posted by nelleish at 11:23 AM on October 2, 2005

Also, female fish are able to store sperm and can use it for several broods.
posted by artifarce at 11:34 AM on October 2, 2005

My first thought was also dropsy, but my only experience is with coldwater fish.

With a goldfish I'd be preparing a salted isolation tank, an immediate water change in the main tank (maybe as much as 50%) and, to be honest, preparing for a humane disposal (though the antibiotics in drezdn's link weren't available last time I saw this).

Longer term, IMO you need to take a serious look at your water quality.
posted by Leon at 3:07 PM on October 2, 2005

Thanks, everyone...It does look like dropsy. I went out and bought some anti-biotics and have put the first dose in the tank. I only have the one aquarium (I thought about just a bucket or something, but it would have no filter or heater, and the medication suggests turning up the heater temperature).

Anyway, I put the medication in and I guess I'll wait and see. According to the package I need to use the medication for five days. I just changed the water yesterday and also tested it's PH and it was fine.

The guy at the store when I first set up this tank said the PH was all I needed to test for, particularly if I'm sure to keep the water changed (and I am). I have no cloudiness and minimal algae, most of which grows on the leaves of a natural plant that I have in there.

If my PH is ok, what else should I be looking at for water quality? The package insert said test the water for bacteria, but none of the test kits at the pet store are for bacteria.
posted by duck at 4:24 PM on October 2, 2005

Agreed, sounds like dropsy, the description of the scales is a giveaway. I'd have to dig out my boooks, but IIRC it's a result of ammonia poisoning. Decaying organic matter (dead babies?) or non-functioning biological filtration is usually the cause of elevated ammonia levels.

(Just looked it up, and one book says it's thought to be caused by elevated ammonia levels, but admits there is "some confusion as to the cause", adding "it is difficult to cure and contagious, so isolate the affected fish until it recovers or has to be destroyed".)
posted by Pinback at 4:27 PM on October 2, 2005

In general, it would be good for you to check the hardness of your water, whether or not your tap water is chlorinated, and maintain low ammonia/nitrite levels. You can buy tests/treatments for all of these at the store.

I don't think these affect dropsy too much but all your fish will be healthier.
posted by nekton at 4:39 PM on October 2, 2005

If you plan on continuing to keep fish, you should get a hospital/quarantine tank. A 10-gallon is a good size, and often you can pick those up for free or very cheap if you look on craigslist or the local classifieds. This is a good primer on quarantine tanks and diseases in general.
posted by acridrabbit at 9:30 PM on October 2, 2005