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Krigjz 02-01-2013 09:49 PM

Harlequin Rasbora problem
Hello everyone,

Over the last three days I've lost 3 Harlequin Rasbora (out of the six I had). The 3 that died seemed to be males. I had 4 males and 2 females. I thought at first that I had been over-feeding them, as two of them got really fat. Then I realized that those two must have been the females when I saw one of them trying to spawn (kept flipping over underneath one of my anubias leaves). My question is, when females are displaying this behavior, is it possible that the males would fight over them?

A couple of days ago, I noticed one of my Rasboras was completely missing his tail fin. This Rasbora died the next day (found him stuck to my filter). One the same day, I found one of my Rasboras dead and tangled in some Java Moss. The day after, I found another dead male floating around. I have 0 ammonia, 0 nitrites, and 20 nitrates. My pH is around 6.8. Temperature is 78f.

The tankmates I have are MTS, 3 Zebra Nerites, 4 Amano Shrimp, and a Bristlenose Pleco.

Did my males have a Battle Royale over the egg laden females? Or is something else happening? They all seem to be swimming around and schooling happily, and they all still scramble to the top during feeding time.

Romad 02-02-2013 07:55 AM

Is it possible that you have something else going on in your water? What type of water conditioner are you using?

Now that your fish numbers are down, you might want to get more females. You could try 3 females for every male and see if the aggression stops.

Krigjz 02-02-2013 07:59 AM

I'm using Seachem Prime.

Now, one of the females is hanging out in the back near the filter, kind of at a 30 degree angle looking up. The other two are swimming and eating fine. The female in the back came out once or twice when the school (if you can even still call it that) swam by, but then went back into the corner. It came out and grabbed a piece of food, then seemed to spit it back out. I'm going to test the waters again and post my results, then probably do a water change.

Edit: Now the two females are hanging out near one of my anubias', basically not moving. The male is swimming around.

Edit 2: And now they're all moving around again...I don't know what's going on. o.o

Krigjz 02-02-2013 12:13 PM

I tested the water again, all the same as above. I did a 25% water change. I then noticed something I had not seen before, a little white worm swimming around! Looking it up, it seemed to be a nematode. I couldn't snap a picture of it before it went back into hiding, but it was thin and white, and swam around like a snake. Could this be a contributing factor? How can I get rid of them?

CelsB 02-02-2013 01:34 PM

I've got four Harlequin Rasbora in my community tank. I've never had any problems and they seem to get along with everything else.

Byron 02-02-2013 05:56 PM

I have never had aggressive issues with any rasbora, and I have maintained and had spawnings with all three common species in Trigonostigma. I think we need to look elsewhere for the cause.

I've no idea what the worm might be. Some are safe, some not. If it is nematodes, the only external sign on the fish would be the worm hanging from the anus. Have you observed this?

Are there live plants? The nitrate is on the high end of safe, but would be better lower. This in itself is not the issue, just something I spotted.

How long have you had the fish? I'm thinking there might be some internal protozoan or pathogen causing this.

BTW, rasbora are not characins, they are cyprinids, so I've moved this thread to that section.


Krigjz 02-03-2013 06:34 AM

Nothing coming out of their anus.

I have a bunch of plants in there.
Bunch of Valls (started with five, but their popping up everywhere!)
5 Java Ferns (Each having like 5-10 new ones coming off)
2 Anubias Nana
Bunch of clumps of java moss scattered throughout.

The nitrates of my water source are actually higher than my aquarium water. They test at ~20-40, so, I can only hope that the plants take in enough of the nitrates. I'm thinking about adding a floating plant, like frogbit, to help some more.

They seem to be a lot more active today. No odd behavior yet from the male or one of the females. The female that was acting odd yesterday is only swimming around in the valls, though. :/

I was thinking about it, and it dawned on me that it could have been a pH swing. I took a tufa rock out, and put a piece of Malaysian driftwood in for my Bristlenose. I'll check the pH again once I get out of bed.

Also, I think two of my snails died...I think. I was lead to believe that the smell would knock me out cold, but they just kind of smelled like snail. One smelled a little worse. Both of their trapdoors are slammed shut. Neither of them have moved at all in the past couple of maybe they are dead, but have not decomposed enough yet. The third one is crawling around but is kind of lethargic.

Krigjz 02-03-2013 07:34 AM

Happy to report that all three of my remaining Rasboras devoured their food this morning.

Byron 02-03-2013 11:39 AM

Diagnosing fish disease/problems is very difficult many times, except for an experienced and trained biologist. These fish may have had some issues from long ago. They seem to be improving, so that is good. You might want to increase the frequency of the water changes for a week or two, i.e., instead of once a week do two or three during that week. Believe me, nothing helps fish more than a partial water change. If you read the "advice" sections of TFK or PFK regularly, almost every recommendation includes a water change as the first "treatment."

Check the pH, this is a possible if it was a sudden and significant change. Regardless of that, lowering the pH will benefit rasbora no matter what; this is naturally a very soft and acidic water fish. And they will always be healthier in such water.


Krigjz 02-05-2013 11:35 AM

My rasboras seem to be acting completely normal again. I am still having a little bit of a nitrate problem, though. My tap water naturally seems to have 20-40ppm nitrate, so water changes keep it around 20-40 (which is not good..). I'm going to get some floating plants this weekend to hopefully eat up some more nitrates. In the meantime, I'm doing a small water change ~(10%) every day to keep the nitrates from raising higher than my tap.

My pH has been dipping a little bit every day, but not much. It was at 7.4 before I took the tufa rock out, and now it is equalizing more towards my tap water's 6. I fear that the more frequent water changes I'm doing will make it dip too quickly, but I'll hope for the best. I am trying to get it back to my tap's pH, I learned my lesson trying to mess with my tank's pH. :/

I thought I lost two of my shrimp, but found out today that they actually shed their exoskeleton. They all went crazy when I did the water change (they like to catch all the floating food, I think), and I counted four! I feel bad for taking their exoskeletons away and stealing their extra calcium now, though. :(

One of my snails was definitely DEFINITELY dead. It smelled like foul foul death. Could this have caused some of the fish death? I think one of my other Nerite snails is dead. It hasn't moved in a while, and was one of the two I found upside down one day (the other one being the dead one). It doesn't smell, though.

I'm going to get more plants and hope they will start to devour my nitrates, then I'll get some more Rasboras to make them a happy school again. I'll keep you posted on whether they are improving or not. Thanks again for your help!

As an unrelated note, you are actually one of the reasons I joined this site Byron, :lol:. When I was researching what to do to start my fish tank, this site kept coming up in google searches. Every question I seemed to google was answered by you. You seem to be the most active member on any aquarium forum. :lol:

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