Pale Harlequin Rasboras

Last week I noticed in the morning that one of my Harlequin Rasboras was not eating (they are normally my gluttons) and he was sort of quietly hanging out at the top of the tank and was moving his mouth a lot. I had just changed the water the day before so my water levels were higher in the tank. I suspected that maybe he was lacking oxygen, so I took a large cup of water out of the tank to increase surface agitation and hopefully increase the oxygen levels in the water. I was leaving for a work trip later that day, so I couldn't do much else.

When I came back two days later, I checked on my tank. The rasbora was still alive, but veeerrry pale. Everyone else in the tank looked fine. I fed everyone in the morning and the pale rasbora ate, a few hours later he got his color back and looked fine.

I've been keeping a close eye on him and I've been noticing that he's been swimming, eating, and acting fine in general, tho his color seems to fluctuate more than the others. Sometimes he's bright, mostly he's a bit duller than the others. His marking is usually more of a dark grey than the vibrant black of the others.

This morning, I noticed a lot of my rasboras were paler than usually. I just turned on the light in the room, so I don't know if the sudden brightness shocked them, because they all looked fine later.

Does anyone have any experience with Harlequins changing colors? Could my one guy be sick, or maybe he just stresses a lot? The there is a little bit of chasing in my tank every now and then, mostly from the male Cherry Barbs, but it's mostly peaceful and no one seems to be constantly getting picked one.

Tank stats:
29 gallon, planted.
Photoperiod: 8 hrs.
Temp: 78 - 80
Ammonia: 0
Nitrite: 0
Nitrate: 10 - 20

7 - Harlequins
8 - Cherry Barbs
1 - Gourami

 

Thanks so much for the thorough information you gave us!

Do you have a lot of hiding spots/breaks in line of sight from the middle to the top?

 

The middle to top isn't that heavily planted in half my tank. The bottom half is pretty covered tho.

 

From my experience, harlequins don't travel to the bottom much. They seem to be strictly mid-top dwellers. Maybe a bit more cover will de-stress your guy?

 

I could try that. I have some overgrown willow hydro I thought about replanting elsewhere. It's strange that it's just the one that looks stressed, the rest look great. I did have a rasbora die from what looked like a fungal something a few weeks ago, so I've been a bit more on higher alert about anything that looks off.

 

That is strange... just a thought on my part.

 

I have lost one rasbora once a month with similar symptoms. The timing is strange, it's like they take their time and take turns dying.

He gets pale "from underneath" if that's makes sense. It loses color from below the skin, looking like pale gray. The dark black "lambchop" turns gray on the edges, then fills in and turns entirely grey. He hides under floaters, starts swimming "up", spine starts to bend. Starts wiggling instead of confidently swimming around. Breaths rapidly, but tank is fine, water parameters very good, it's the only fish acting that way.

I have since moved it to a "hospice" tank. Decided to euthanize any fish with these symptoms going forward.

Other rasbora have had open sores on side of body. Furan 2 helped with that, but they still look a bit emaciated. Treated with prazI pro, kind of helped but no silver bullet. VitaChem helps keep them alive, which made me think it's a parasite.... Like they aren't getting enough nutrition from their meals. Once they stop eating it's usually game over.

I thought it was fish TB or some parasite. Still not sure what it was. Keep us posted!


Edit: Btw, my rasbora turn pale when scared, light turns on suddenly etc, that's normal. The paleness I describe is different... You will feel like something is definitely wrong. It's a sickly gray, not just pale. Hopefully he's ok and not what my rasbora have. Good luck

 

Ive always heard that Rasboras were very hardy, which is why I chose them over cardinals. Is there a rasbora disease similar to what neons and dwarf gouramis can get?

Thanks for your story bigdreams. Hopefully it doesn't turn out like that.

 

Dwarf Gouramis get iridovirus, neon tetras and rasbora get neon tetra disease:

I am thinking maybe my rasbora have this neon tetra disease... I reread the links above... sounds like a positive match... then again, "persistent coughing" matches everything from a common cold, flu, to lung cancer.. so who knows. The symptoms I have in my rasboras do follow the ones above, though....

btw, Cardinals are resistant to neon tetra disease... was main reason I got them in the first place... I just hope my lemon tetras don't get sick now.

 

Was able to get a picture of him. What do you think?




Here's one of my healthy rasboras for color comparison.

 

The dorsal profile does make him seem a bit thin and he seems to be clamping unless that's just when you caught him swimming. Have you noticed any clear poops?

 

I did notice some white stuff coming out right after I snapped the pic. It looked more fluffy rather than stringy. I'm thinking maybe internal parasites?

 

Very possible! I use Prazipro and it seems to work well. It's also pretty mild and won't disrupt your biological filter.

 

If it's an internal parasite, should I use a medicated food?

Edit: Maybe soak some freeze dried treats (or their normal flakes/pellets) in garlic juice or Seachem Garlic Gard? Just reading up on parasite treatments...

 

Yes, you can certainly use medicated food instead. It's said to be the best remedy but some fish refuse it. Good luck, let us know how things turn out!