Sudden Pearl Gourami Death- concerned for tankmates

[PygmyPepperJulli]

Hi TFF,

Haven't been on in a while, but I do have a minor emergency that needs addressing.

DETAILS
55gal
1 Angelfish, 9 neon tetras, 4 yoyo loaches, 1 bristlenose catfish, 1 male ram cichlid, lots of plants, and up until 5 minutes ago, 5 pearl gourami's.
50% water change weekly
Just added salt according to @Colin_T's normal instructions and have replaced water and wiped glass.
Tank parameters- 0 ammonia, 0 nitrite, ~5ppm nitrate (according to API water test kit)
Has been established for ~a year? year and a half? No idea. Was cycled when started, if that helps
Recently added- yoyo loaches. Were a surprise present I found in my tank when I got home ~two weeks ago (and subsequently were not qt-ed) however have not displayed any signs of illness. They seem a bit weird, but from looking online that seems normal for them.
No other fish displaying signs of illness.

Pearl gourami was fine this morning, came home and was clearly struggling to swim (sinking to bottom followed by rapid spiralling in any direction to get back to the top) with something on it's head (though it quickly came off as it was thrashing around, I suspect some kind of debris that was coincidentally there rather than a type of fungus). I do not really suspect bullying, as it was (80% sure) a female with 3 (I think) other females and a very dominant male, who never fought. I also do not suspect the angelfish, who although is the reason for the 'mysteriously' shrinking number of neon tetras has never had a go at any of the gourami.
Was immediately qt-ed (10 gal spare) and salt added to both tanks- however, died around 10 mins after adding to qt. This may have been human error, as it was a fast transfer into the tank (mostly due to me panicking), or a rapid deterioration.

My main queries-
1. Any thoughts on what it could have been? It was sightly skinnier than I would have liked, however not to the point of sunken belly or anything like that, so I don't believe worms. No signs of stringy white poop, pineconing scales, etc. Possibly a bacterial (sudden death) or internal protozoan infection (weird swimming, has happened to me before and was told possibly protozoan on brain)?
2. Is it likely to spread to other inhabitants? I am a little confused about this, as I would have thought if it were something contagious or a water quality issue, the rams or yoyos would have experienced symptoms or death first (I believe these are more 'delicate' fish and susceptible to change more than gouramis).
3. If yes to the above, what preventative measure would you recommend? I have no meds other than aquarium salt and not really on the budget to buy any, but can try. I will do several water changes this week to hopefully flush out whatever is wrong (continuing to add salt) unless recommended otherwise.

Thank you for your time and apologies for the long post,
PPJ

 

[PygmyPepperJulli]

Also, really sorry, but if photos are needed, I can't take them. A, the fish is now dead and buried, and B, I don't actually have anything I can take them with.

 

[Colin_T]

Pearl gourami was fine this morning, came home and was clearly struggling to swim (sinking to bottom followed by rapid spiralling in any direction to get back to the top) with something on it's head (though it quickly came off as it was thrashing around, I suspect some kind of debris that was coincidentally there rather than a type of fungus). I do not really suspect bullying, as it was (80% sure) a female with 3 (I think) other females and a very dominant male, who never fought. I also do not suspect the angelfish, who although is the reason for the 'mysteriously' shrinking number of neon tetras has never had a go at any of the gourami.

Spinning and spiraling through the water is an issue in the brain. It can be caused by a bacterial, viral or protozoan infection in the brain or a blow to the head. If the fish jumped out of the tank and landed on its head then it had brain damage from that. Otherwise a protozoan infection is the most likely cause. These are caused by dirty tanks/ filters, or tanks with lots of gunk in or that get fed lots of meat/ frozen foods.

There's no cure for the infected fish but doing a big water change and gravel cleaning the substrate every day for a week, and cleaning the filter, usually stops it affecting other fish. Salt can also help stop it spreading if it's protozoan but cleaning the tank and filter is first and then add salt to the main tank for 2 weeks.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

The dose rate for salt is 2 heaped tablespoons of salt for every 20 litres of water.

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Sinking to the bottom when the fish stops swimming is normally a swim bladder issue and there's no cure. Fish are normally euthanised when this happens.

The stuff stuck on its head was probably gunk sticking to excess mucous. If the fish was stressed it would have produced more mucous and that allows things to stick to it easier.

 

[PygmyPepperJulli]

Thanks Colin.

I'm not really sure how the protozoan got there (I always try and vacuum up all the mulm and gunk when cleaning the tank)- however, since you mentioned meat/frozen foods I do occasionally feed them small chunks of frozen prawn (human food grade), to vary their diet from the normal Hikari sinking pellets (for the loaches) and sinking-pellet things. Should this practise be discontinued or is this more of a once-off event? It may of also had a blow to the head, but it definitely didn't jump out (for one, I have tight-fitting lids, and it also wasn't on the floor).

Will definitely be doing water changes throughout the week with salt and clean the filter.
The fish didn't seem to have more mucous than normal (not sure if excess is visible) but that would make sense.

Is it normal for these types of illnesses to kill this quickly? As far as I could tell, it didn't have any symptoms when I fed them this morning.

 

[GaryE]

There is another possibility, said a guy who kept pearl gouramis for many years. They are lovely fish, but they have one special bad habit that may be your problem.

They murder each other. It's quiet, discrete and fast. A sharp hit to the gill area along the keel of the fish will produce exactly what you described. I lost a few this way, and was perplexed til I saw it happen. They spar, and things get out of hand. I've seen the same 'killing method' in pairs of Cichlids that go to war with each other. They have a vulnerable spot.

I used to like the old hobby idea of a centrepiece fish for community tanks, and pearls were my go to. For close to 20 years, I don't think I had a tank that didn't feature as a small group of them. They are beautiful, delicate looking things, but they don't have delicate personalities. They have an edge to them. They're gouramis. The traditional lalius dwarf gourami is even worse for that.

It could be a different cause, but they do have a tendency to anger and send group members off to sleep with the humans.

 

[PygmyPepperJulli]

Well, that's certainly a possibility...

Was there ever any reason that they suddenly murdered each other? And is there any way to prevent this from happening again (because I don't exactly want any more murders on my hands...)? Out of all of them, the one that died was the only one that I thought had any chance of being a male (I think... they all look incredibly similar except for the dominant male), so maybe a territory spar, but since I've NEVER seen them fighting, I'm not sure why they'd suddenly decide to now...

Do you still use them as centrepiece fish or have you given up due to the problem described?

 

[Colin_T]

Protozoa are in every waterway around the world. If you have fish in a container of water, there will be protozoa in the water. They come in with fish, shrimp, snails, plants and water from pet shops.

Aquariums are a soup of microscopic organisms like protozoa, bacteria, fungus, viruses, and all sorts of other gross things. It's one of the reasons I recommend doing a large (75%) water change every week. Not to keep the nitrates down, but to dilute the number of pathogens in the water. The water changes help keep nitrates down too but water changes should be done to reduce the number of disease organisms in the water.

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It's fine to keep feeding the fish raw or cooked prawn a few times a week as part of a varied diet. If you have live shrimp in the tank, use cooked prawns so they don't transmit diseases to the shrimp you keep. Cooked prawn also prevents Microsporidian infections from infecting fish if they eat a prawn that has it.

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Excess mucous can be clear if there's only a little bit more than usual, or cream, white or grey, depending on how much there is. The more mucous produced by the fish, the whiter or greyer they go.

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Infections in the brain can kill within a couple of days (sometimes less) of the fish developing it. Most times you don't notice anything until the fish starts to barrel roll through the tank. They die shortly after that. In some fish (usually the lighter coloured ones) you can see a pink or red area in the face, sinus and head area when they are infected. It's harder to see in darker coloured fish. You don't always see the pink area but it does sometimes appear just before they show symptoms.

 

[Magnum Man]

@Colin_T ... said Infections in the brain can kill within a couple of days (sometimes less) of the fish developing it.

there must be something else out there that does this... I have 2, what I call "retarded" fish, that I've had for so long, I don't remember the 1st time I saw the unusual behavior, but there are 2-3 old threads here I've posted before... one is an angel, one is a Serbei Cory... coincidentally or not, they are both in the same tank, which is a densely populated Tetra community tank, & no other fish are effected... both are so effected, that I expected each to die a long time ago... the Cory is most severely effected, & often looks like a drunk person inner tubing in the river... often floating vertically near the surface, but is capable, and does act normally at feeding time, but spends most hours acting drunk... the angel fish, act like a downs syndrome person, often just spending time starring into nothing... both have conspecifics, that don't treat either meanly... the other angel used to treat the other like a big sister, but lately seems to have gotten tired of that, the other Cory's in the tank, just pretty much ignore the one floating at the top, but treat it like normal at feeding time, when that one is acting normal... I've often thought about euthanizing, each, but even the weakest tetras, haven't shown the condition to be contagious???

one of my previous threads

Mental “wasting” disease???

So I have had a Serbi Cory, for over or around a year, that is just not right… the other Cory’s don’t hang with it… it eats normally, but doesn’t swim with the same purpose as the rest do, sometimes it looks like it’s going to die, but keeps on going… this morning, at 1st. Light, I noticed one...

www.fishforums.net

 

[GaryE]

I don't keep pearls anymore, as I decided that centrepiece idea was for displays, and not for vibrant tanks. I lost interest in using fish as aquascaping. If I were to get pearls, they'd be in their own tank now, so I could see their behaviour more closely.

I'm not discounting the idea of the protozoan infection. It's just that this can be a one off problem, related to hormones and bad luck. Two fish can spar for months, and never deliver a fatal blow. Or they can get into their first fight, and one can die.

What to do? @Colin_T has given advice you can act on. I've offered an observation that you can't do a thing about. So in the rather safe than sorry, I'd follow Colin's advice. Any time I see anything off in a tank, I check for gunk, and double the frequency of my water changes. I have a whiteboard out in the garage where I keep my tanks, and I just marked my routine water changes - every 7th day now for several weeks. I might slip to 8 or 9, but try not to. If something odd happens, then I try to go to every 3-4 days for a couple of weeks.

 

[Colin_T]

there must be something else out there that does this... I have 2, what I call "retarded" fish, that I've had for so long, I don't remember the 1st time I saw the unusual behavior, but there are 2-3 old threads here I've posted before... one is an angel, one is a Serbei Cory... coincidentally or not, they are both in the same tank, which is a densely populated Tetra community tank, & no other fish are effected... both are so effected, that I expected each to die a long time ago... the Cory is most severely effected, & often looks like a drunk person inner tubing in the river... often floating vertically near the surface, but is capable, and does act normally at feeding time, but spends most hours acting drunk... the angel fish, act like a downs syndrome person, often just spending time starring into nothing...

They could be a bit slower mentally than the other fish. Looking at the link you posted, it might be a brain worm or parasite in the brain. There are parasitic worms that get transferred around in bird poop and snails ingest the worm eggs. The worm goes into the brain and causes the snail to hang out in the open during the day so it gets eaten by another bird. There's a similar parasite that affects mice and rats and they stay out in the open during the day so they get eaten by predators and the parasite's lifecycle can continue. There's also a fungus that infects ants and gets them to climb up the highest bit of plant and die there so the fungus can shed spores over a larger area. It might be possible the fish have picked up something like this.

It could also be a slow growing tumour that is putting a bit of pressure on part of the brain and making the fish less responsive.

They could have a physical issue (maybe heart, kidney or liver problems) that is making them feel a bit off colour and they are less likely to go racing around with the others because they are tired.

 

[PygmyPepperJulli]

Thanks all.

On Colin's advice, I'll do a number of water changes (hopefully about 3 60%s) this week- the reason I can't really do more (this week and a higher % every week) is that we're on tank water (rather than council water) which is running a little low at the moment. Filter has been cleaned and large water change done.

Pretty sure the prawns I feed are bought cooked, but would it be better to cook them again to remove potential infection, or just leave them? I usually just get a small chunk out, let it thaw for a few minutes (don't want to freeze any fishy insides), then chop it into small bits and feed. No shrimp in tank, so that's not an issue.

Honestly, it could be either of these theories- it may have had a protozoan and I just didn't notice any small symptoms until it was death-rolling or it may have decided it had issues with Chonk (the alpha male, I didn't name it), or Chonk had issues with him...

Magnum Man, that is really rather weird. Especially how it's fine at feeding time... maybe just attention seeking behaviour?

Hopefully everything resolves and there aren't any other issues, but will keep you all posted if something changes.

Thanks for all the help!
PPJ

 

[Colin_T]

If the prawn is already cooked then you don't need to cook it again.

 

[PygmyPepperJulli]

I'm very pleased to report there has been no other symptoms of sickness or sudden deaths in the tank, so hopefully it was a one-off event (whatever caused it). Thank for the help everyone