Under microscope clownfish fecal sample looks suspicious

mcgullen · Mar 20, 2022

I noticed an hour ago that the 2 baby clownfish I rescued 4 days ago have white, stringy feces. Background here: https://www.reef2reef.com/threads/clownfish-rescue-mission.900271/

I took a sample. Under 100x microscope I noticed two suspicious things that are most likely pathogens. Any help in IDing them would be greatly appreciated.

Suspect A: round, cell looking things that appear to have a nucleus each. I saw 8-10 of them in the smear sample.
Could these be parasite ova/cysts?

Suspect B: multiple black specks rapidly swimming around. Here is a video showing one. Is it the right size to be hexamita or another flagellated protozoa?

Thank you!

Jay Hemdal · Mar 20, 2022

mcgullen said:
I noticed an hour ago that the 2 baby clownfish I rescued 4 days ago have white, stringy feces. Background here: https://www.reef2reef.com/threads/clownfish-rescue-mission.900271/

I took a sample. Under 100x microscope I noticed two suspicious things that are most likely pathogens. Any help in IDing them would be greatly appreciated.

Suspect A: round, cell looking things that appear to have a nucleus each. I saw 8-10 of them in the smear sample.
Could these be parasite ova/cysts?

Suspect B: multiple black specks rapidly swimming around. Here is a video showing one. Is it the right size to be hexamita or another flagellated protozoa?

Thank you!

Was the fecal sample what is called a "clean catch"? That is, did you get it right from the fish, or had it been laying on the bottom of the tank for a bit?

At 100x, those little black things are tiny and fast, not sure what they are.

The larger things could be ova, but I've also had issues with eggs from food going undigested through the fish, were they fed mysids?

Jay

mcgullen · Mar 20, 2022

Hi @Jay Hemdal !

1. Yes, it's a clean catch. I used a pipette to get it right from the fish.
2. They were fed frozen brine shrimps. I just checked and there indeed were some eggs mixed in the frozen cube. I believe clownfish cannot digest unhatched brine shrimps.

Those black things move very fast indeed. I am trying to isolate them to see how they would react to a metronidazole emulsion I prepared. There is no other practical way for me to ascertain what they are at the moment...

Jay Hemdal · Mar 20, 2022

mcgullen said:
Hi @Jay Hemdal !

1. Yes, it's a clean catch. I used a pipette to get it right from the fish.
2. They were fed frozen brine shrimps. I just checked and there indeed were some eggs mixed in the frozen cube. I believe clownfish cannot digest unhatched brine shrimps.

Those black things move very fast indeed. I am trying to isolate them to see how they would react to a metronidazole emulsion I prepared. There is no other practical way for me to ascertain what they are at the moment...

The dose for metronidazole in food is around 5000 ppm. If you make up a solution/emulsion similar to that, and it kills the little motile protozoans, that could direct you to a treatment. The trouble is that metro in food at that level is very bitter and some fish refuse to feed on it.

Jay

mcgullen · Mar 21, 2022

Jay Hemdal said:
The dose for metronidazole in food is around 5000 ppm. If you make up a solution/emulsion similar to that, and it kills the little motile protozoans, that could direct you to a treatment. The trouble is that metro in food at that level is very bitter and some fish refuse to feed on it.

Jay

The 2 baby clownfish are too small to be fed seachem focus pellets--with their combined weight around 0.4g, dosage is too minute to get right. And the seachem focus slurry will not be small enough for their mouth.

As a compromise, first dose of metronidazole went in tank water at a low concentration of 2mg/L about 2 hours ago. No adverse effect noted yet. Fish continue to show good appetite.

Planning to dose every 48 hours for at least 10 days. That seems to be the R2R guideline.

Will gradually increase the concentration to 4mg/L.

Will continue to monitor for white feces or signs of aggravated illness.

Fingers crossed. Hope the little one can recover.

Jay Hemdal · Mar 21, 2022

mcgullen said:
The 2 baby clownfish are too small to be fed seachem focus pellets--with their combined weight around 0.4g, dosage is too minute to get right. And the seachem focus slurry will not be small enough for their mouth.

As a compromise, first dose of metronidazole went in tank water at a low concentration of 2mg/L about 2 hours ago. No adverse effect noted yet. Fish continue to show good appetite.

Planning to dose every 48 hours for at least 10 days. That seems to be the R2R guideline.

Will gradually increase the concentration to 4mg/L.

Will continue to monitor for white feces or signs of aggravated illness.

Fingers crossed. Hope the little one can recover.

That dose for metro seems too low. Gratzek and Blasiola give a dose of 6.6 mg/l daily for three treatments. Langdon gives 25 mg/l every other day for three treatments.

Jay

mcgullen · Mar 22, 2022

Jay Hemdal said:
That dose for metro seems too low. Gratzek and Blasiola give a dose of 6.6 mg/l daily for three treatments. Langdon gives 25 mg/l every other day for three treatments.

Jay

I have good news to report! Day 3 into treatment with dose now at 4mg/l, both fish are having normal feces! Will do a water change tomorrow, and the 3rd dose at 6mg/l the day after.