What is killing my fish? Parasites?

[tuux1598g]

Hi all,

Lately I've been having some major issues with fish appearing to starve to death. Most recently 2 Honey Gourami, and 3 female guppies along with a number of guppy fry.
I've spent some time looking at water quality - which appears perfect every time it is tested (including right after a death occurs).
I've increased water surface agitation and circulation to ensure good oxygenation, wondering if that was a contributing factor - the remaining fish appear more active as a result of this. But the deaths continue.

I've attached some photographs, I've had a fry die today, and one that looks close. The general pattern seems to be:

1. The fish are eating, but loosing weight
2. They become less interested in food
3. They continue loosing weight, until their head is the largest girth (viewed from above), with a tiny thin body
4. (With guppies) their tail fin appears to get quite thin (clamped?)
5. (With guppied) their body appears to turn a darker, almost black, colour.
6. They float around relatively listless for up to 24 hours. I've also quarantined them off, and tried feeding individually with no luck here.
7. (With multiple guppies) I observed what I first thought was "fry" appearing from their anus region - but now realise it is not.
8. Very soon after, they die.

I'm suspecting some type of parasite, but don't have much of an idea where to start. Any help would be greatly appreciated.

I've attached four images. 2 angles of a guppy fry roughly 3 weeks old, that has recently (hours) died after "appearing to be giving birth". 2 angles of a live guppy fry, same age, exhibiting similar behaviors and likely to die soon

Current water parameters:
NH4/NH3: 0ppm
NO2: 0ppm
NO3: 5ppm
GH: 8 dGH
KH: 6 dKH
pH: 7.2
Temp: 26 C
PO4: 0ppm (stopped fertz and CO2 for a week)

Tank is medium planted ~50 gal (200L). Pressurised CO2 injected to ~15-20ppm.
Weekly 30% water change.

Livestock:
- 15 cherry barb
- >15 guppy fry
- 3 adult guppies
- 1 honey gourami
- 7 amano shrimp

Also a quarantine tank with:
- Pleco L128 - Blue Phantom
- Pleco L471 - White spotted dwarf hypancistrus

Thanks!

 

[FishGuest5123]

I have some wasting away also but they don’t get that bad. Hopefully, @Colin_T can offer some insight. I have tried Paraguard with no success.

 

[Colin_T]

how long does it take them to go skinny?
does it happen over a week or over a couple of months?

if you post pictures of fish, try to have them against a coloured background and photograph them from the side.

 

[FishGuest5123]

Mine take several weeks. I don’t want to hiJack the post with my pics.

 

[tuux1598g]

I'd say it takes a week or two for them to go skinny.

They seem to drop some weight, but continue feeding for a while. Then they get really skinny within a day or two before death and then they excrete that mess you see on the photos an hour or two before death.
The fry are exactly 3.5 weeks old - so they thrived initially, but within the past week a few have died, and yesterday I lost 2 more of them.

Another observation: so far the Cherry Barbs seem to have been largely unaffected. Not sure if that is just pure chance though.

Re: photos, I'll try to get a coloured background next time. Very difficult to capture as these fry are tiny.

 

[Colin_T]

If they eat well but lose weight rapidly (over 1-2 weeks), they have an internal protozoan infection.

Metronidazole is the medication of choice for internal protozoan infections.

Before treating any tank:
Wipe the inside of the glass down with a clean fish sponge.
Do a 75% water change and gravel clean the substrate.
Clean the filter if it hasn't been done in the last 2 weeks.
Remove carbon from filter and increase aeration before using any medications.

Protozoan infections are common in all tanks but flourish in dirty tanks. Make sure you do big regular water changes and gravel cleans each week, to minimise the number of nasty organisms in the water.
*NB* Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Make sure the fish get good quality food that is suited to the type of fish (eg: plant based diet for vegetarian fish, marine meat diet for predatory fish).

 

[Lajos_Detari]

I guess you can try MetroPlex by Seachem which will treat the internal parasites (but I have never used it before).

Seachem - MetroPlex

www.seachem.com

But when you buy this medication, make sure that it's still in powder form(in good condition).

There was once I bought a medication from Seachem that turned bad as the powder all clumped/stick together and I had to return it to the shop.
When I showed it to the shopkeeper, he tried to open other boxes and he found that all the boxes have the same problem.
In the end, he refunded me as none of his stock can be used.

 

[tuux1598g]

Thanks for the great insight, sorry for the delayed reply - partly holiday season, and partly hunting down Metronidazole in this market (difficult).

I've managed to get my hands on two products that appear to be relevant, any advice on which to use/how greatly appreciated:

1. Azoo Anti-Endoparasites - claims to treat internal parasites, contains Mebendazole and Metronidazole from what I can make out (only listed in Chinese) and in unknown quantities
2. Sera med professional Flagellol - claims to treat flagellates/Hexamite, online I found it contains Menadione and Thiazole

It is very difficult to find any products here that even list their ingredients, and the specific Metronidazole is not common.

I've attached images of the bottles, including administration instructions for reference.


Thanks in advance

 

[Lajos_Detari]

I guess the Azoo Endoparasites should be good to use. It's Taiwanesw brand.

See another forum discussion.

https://www.monsterfishkeepers.com/forums/threads/deworming-fish.459866Ll