White Fantail Goldfish Died: Why the Dark Abdomen?

by Muffin
(California)

Intro: This morning I found my parents' white fantail goldfish dead in her tank. The first thing I noticed was that her belly looked dark -- but it's not her scales/outside, it's her insides. Because she's white she's sort of transparent, and it looks like her insides turned brown, kind of.

Question:
So my question is has anyone seen this before and if so, do you know what that means? Is it indicative of how she died?

Background:
This is kind of a long background, but I want to try and give the full context.
- My parents got a weird "artwork aquarium" a couple months ago (100 gallon). They hired a professional to come in once a week to work on the water and whatnot.
- About a month ago they bought the white fantail (Hishi) and she seemed to do well.
- About 10 days ago they bought two more fantails (Brutus and Stewart).
- My parents DID NOT quarantine Brutus/Stewart. Just put them right in the main aquarium (I know this was wrong, they did no research and I didn't find out that was wrong until the fish started getting sick and I started researching myself).

Sunday:
- The fish did well for about a week or so, then Sunday morning we found Hishi at the bottom of the tank looking extremely ill.
- I bought a 5 gallon aquarium and filled it with water from the 100 gallon aquarium. Helpful employee at Petsmart looked at a photo of her and saw red streaks in her tail, said it was probably ammonia poisoning and helped me buy aqua salt and Melafix.
- I managed to get her out and into the new isolation tank. I added a little aquarium salt and Melafix.

Monday:
- The next couple days were up and down. She seemed better in her isolation tank but still lethargic/floating still in corners.
- I changed out some of the water (treated with Stress Coat and Quick Start and more Melafix and aqua salt (all API)). Her fins and tails had red streaks and sort of "shredded" and then shed, which I read was normal for ammonia poisoning but they could maybe grow back.
- Then I notice that she started getting red patches that looked like hemorrhaging, a little on her belly, her front fin and her back fin.
- BUT my parents' "aquarium specialist" came by Monday afternoon and tested the main aquarium's water and said it tested 0 for ammonia and nitrates.
- So my theory was possibly hemorrhagic septicemia.
- MEANWHILE, Brutus and Stewart started lurking at the bottom of the 100 gal aquarium and Brutus started getting red streaks in his tail.
- So I bought another quarantine tank (3.5 gallons) and put Brutus in that with treated water (Stress Coat, Quick Start, Melafix, aqua salt).
- I also put a small amount of Tetra Lifeguard in Brutus' tank, but not Hishi's.

Tuesday:
- Both Hishi and Brutus seemed okay, not great. Stewart remained in the main tank, no red streaks in his fins.
- THEN I notice a white dot on Hishi's head. I thought it was weird so I checked online and learned about Ich. I went to see if Brutus had anything like that, and sure enough he also had a couple white dots on his head.
- So at this point I'm just like, omg, what else could go wrong? It makes sense they got Ich because their immune systems were clearly weakened, but I was still trying to figure out if they had ammonia poisoning or bacterial infections.
- Anyway, I got two mini heaters for Brutus and Hishi (preset 78 degrees).
- Meanwhile, I began setting up a 20 gallon tank. Put 15 gallons in, treated with Stress Coat, Quick Start, Melafix, and aqua salt then started filter. Added a tank divider down the middle and a heater.
- Once the 20 gallon tank got to 78 degrees, I put Brutus in.
- Then I cleaned his 3.5 gallon tank, refilled it, treated it, and put Stewart in that and started heating it back up to 78 with the mini heater.
- Then I put Hishi in the 20 gallon tank, on the other side.
- Once both Hishi and Brutus were in the 20 gallon tank, I put a tablet of Tetra Ich Guard in the tank (forgot to remove filter, removed it like two hours later when I found out I needed to).

Wednesday:
- All fish were doing well enough.
- (morning) I cleaned Hishi's 5 gallon tank, refilled it, treated it (the usual) and moved Stewart in there because it was bigger. I then added 1/3 tablet of Ich guard (I removed the filter).
- Meanwhile, Hishi was looking a bit better. Her red marks/hemorrhaging had actually cleared up!! Her left fins were super messed up (looked like an amputee at the elbow), but I was happy she was doing better. Swimming around, no more red...seemed to finally be moving in the right direction.
- Brutus also looked healthy. Still some red streaks, and both fish had more white marks, but I read that was normal when you turn up the heat and quicken the gestation of Ich.
- I turned up the heat by a degree every couple hours in the 20 gallon tank and added some more aqua salt to increase the salinity (5 tablespoons dissolved in water, added in over a couple hours).
- Evening: I treated 3 gallons of new water with the usual. Then I removed 3 gallons from the 20 gallon tank (a little less than 25% of the 15 gallons in there) and slowly replaced with the new water. I made sure the temperatures matched!! About 80 degrees at this point.
- THEN I put another tablet of Ich guard in the water (no filter).
- Brutus and Hishi both seemed happy. I got them both to eat 3 pellets of food, and they were swimming around.
- BTW: the 20 gallon tank is a "bubble tank" so there was definitely sufficient oxygen in the water despite being 80/81 degrees. I know Goldfish don't love the currents but I thought being able to breathe was more important.
- 11pm: final check in, they seem well. Added final bit of replacement water.

Thursday:
- Found Hishi dead near the filter, floating upside down :(
- Got her out into a little bowl, took pictures of her weird dark abdomen and then buried her in the backyard.

- Stewart looks well in his 5 gallon tank. He has more white dots on his head, but we did replacement water this morning (1 gallon, so 25% of the 4 gallons in there).
- Brutus looks okay. He had a really long stringy white poop which I know is indicative of bacterial infections. I washed and refilled the 3.5 gallon tank with 2 gallons of new/treated water (usual treatment) and 1 gallon of water from the 20 gallon tank. Let it filter for a bit then moved Brutus in there so he wasn't lingering in the tank Hishi died in. I then added about half a tablet of Tetra Lifeguard for possible infection (I removed the filter).

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Grant’s Reply

Hi Muffin
Yes, the post is long, but there is no such thing as too much information.
I have a clear idea of events, and I don’t have to make assumptions.
Hishi was a matt scaled fantail. Matts are the weakest of the three main scale groups, metallic, nacreous and matt.

Ammonia or Nitrogen Cycle

Just to be clear about the ammonia (nitrogen) cycle, any new aquarium filter must go through an ammonia cycle before it is safe for fish to be put in the aquarium.
What normally happens is a new aquarium is set up, fish added, two/three weeks later there is an ammonia spike, and the fish get sick or die.
With just one fish in 100 gallons, the filter should have been able to cope with the small amount of ammonia, and I would also assume that the professional hired by your parents knew about cycling new aquariums.
A water test kit is cheap, and I would suggest getting one so you can test the water yourself so you know when a water change is necessary. Don’t get test strips as they are too inaccurate; get the kit that has test tubes and test solutions in it.
I would have assumed like the Petsmart employee that an ammonia spike had occurred, and the salt and Melafix were good treatment options.

Hemorrhagic Septicemia

Viral hemorrhagic septicemia has no cure, and you observed that the redness on Hishi actually cleared up, so we can safely assume it wasn’t that.
There are many causes of redness in Goldfish such as bacterial, fungal or parasitical.
Looking at the images, Hishi didn’t die from Ich because there aren’t enough cysts present.
Bacterial and fungal causes can also be eliminated because of the salt and Melafix treatments.
Concerning the dark abdomen, sometimes fish that develop an internal tumor exhibit this coloration, but she wasn’t abnormally rotund, so, in the absence of a necropsy, I think it is due to something like blood pooling in the body cavity after death.
Another possible cause could be bacteria or parasites attacking the internal organs, but that would be a long shot considering all the other medications she was receiving, especially salt.
Reviewing all the medications and treatment levels, I believe Brutus and Stewart introduced either a protozoan parasite or flukes.
None of the treatments you have used, at the levels indicated, will kill flukes or protozoan parasites. (I’m not sure if Tetra Ick Guard will treat protozoan parasites, which Ich is one.)

In Summary

I would treat Brutus and Stewart for parasites using a praziquantel based medication such as API General Cure. This medication kills all external and internal parasites, and is filter friendly.
I would treat them after the Ich has cleared up.
Really long stringy white poop is an indication of indigestion caused by poor quality food, not a bacterial or parasitical problem.
Sick Goldfish shouldn’t be in strong water currents as this saps their energy needed for recovery.
Salt administered at the right level (0.3%) or a tablespoon per gallon, will cure 90% of all Goldfish ailments, except flukes. Plain un-iodized 100% cooking salt is just as effective as aquarium salt, and is a lot cheaper.