"Is this an Ich trophont?"

[Mr.Yan]

Hi everyone,
I am a marine fish vendor from China, and I've learned a lot from this amazing community. Thank you all so much for the valuable resources here.
Recently, I've encountered a severe crisis with a massive die-off in my quarantine system, and I desperately need your expert help to identify the pathogen.
System and Symptoms Background:
• System: 200-liter commercial quarantine tank.
• Inhabitants: High-density shipment of wild-caught juvenile angelfish (such as Blueface Angels and Koran Angels, around 4cm in size).
• Current Medication: The system is continuously treated with Copper Power (maintained strictly at therapeutic levels, around 2.5 ppm).
• Clinical Signs: Interestingly, there are absolutely no white spots or symptoms visible on the body surface or fins of the affected fish. However, the Blueface and Koran Angels exhibit severe body discoloration and fading (pale skin) before dying.
Microscope Findings (from Gill Scrapes):
Upon performing gill scrapes on the dying/dead fish, I found that their gill filaments were severely eroded and necrotic. Under the microscope, the gills are covered with the organisms shown in the attached images.
Given that the fish have been in therapeutic copper the whole time and their body surfaces are completely clean, I am deeply confused:
1. Are these Ich (Cryptocaryon irritans) trophonts that are somehow completely confined to the gills?
2. Or am I dealing with a severe infestation of gill flukes (Dactylogyrus) or perhaps the peracute, gill-only stage of Marine Velvet (Amyloodinium)?
3. Could the white dot-like lesions in the gills actually be mucus plugs/tissue necrosis caused by something else, or are they the parasites themselves?
I have access to raw chemical powders including Kanamycin, Metronidazole, Praziquantel, and Fenbendazole. I would deeply appreciate any diagnostics on these microscope images and advice on how to save the remaining fish.

P.S. English is not my native language, so I am using an AI translator for this post. Please excuse any unnatural phrasing or grammatical errors. Thank you for your kind understanding and patience!
Thank you so much in advance!

 

[Mr.Yan]

 

[Mr.Yan]

 

[vetteguy53081]

While this image may be,,,, please post a couple of pics of fish. If it only has a dot or two, can be sand grains or a skin tag as examples. Ich will increase in number and location each 24 hour period

 

[Mr.Yan]

While this image may be,,,, please post a couple of pics of fish. If it only has a dot or two, can be sand grains or a skin tag as examples. Ich will increase in number and location each 24 hour period

I’ve uploaded the video and photos, but it seems you can’t see them?

 

[Mr.Yan]

While this image may be,,,, please post a couple of pics of fish. If it only has a dot or two, can be sand grains or a skin tag as examples. Ich will increase in number and location each 24 hour period

I’ve uploaded the video and photos, but it seems you can’t see them?

video

 

[vetteguy53081]

video

Was asking for pictures of the fish

 

[Mr.Yan]

video

Was asking for pictures of the fish

These photos were taken right before they died. Their gills were full of these parasites, but there was nothing visible on their bodies.

 

[vetteguy53081]

These photos were taken right before they died. Their gills were full of these parasites, but there was nothing visible on their bodies.

Sorry for loss and it appears to be flukes especially shown on the emperor angel

 

[Mr.Yan]

These photos were taken right before they died. Their gills were full of these parasites, but there was nothing visible on their bodies.

Sorry for loss and it appears to be flukes especially shown on the emperor angel

Thank you so much for your detailed reply! I also suspect it was gill flukes, but I really struggle to tell them apart from Ich trophonts under the microscope.

 

[mcarroll]

IME (tho limited) the paling skin is a tell for "flukes". Interesting there was no sign of them on the skin though as blotchy skin is also a pretty typical sign.

 

[Mr.Yan]

IME (tho limited) the paling skin is a tell for "flukes". Interesting there was no sign of them on the skin though as blotchy skin is also a pretty typical sign.

I initially thought it was Brooklynella in the gills

 

[Jay Hemdal Verified Community Expert]

Hi everyone,
I am a marine fish vendor from China, and I've learned a lot from this amazing community. Thank you all so much for the valuable resources here.
Recently, I've encountered a severe crisis with a massive die-off in my quarantine system, and I desperately need your expert help to identify the pathogen.
System and Symptoms Background:
• System: 200-liter commercial quarantine tank.
• Inhabitants: High-density shipment of wild-caught juvenile angelfish (such as Blueface Angels and Koran Angels, around 4cm in size).
• Current Medication: The system is continuously treated with Copper Power (maintained strictly at therapeutic levels, around 2.5 ppm).
• Clinical Signs: Interestingly, there are absolutely no white spots or symptoms visible on the body surface or fins of the affected fish. However, the Blueface and Koran Angels exhibit severe body discoloration and fading (pale skin) before dying.
Microscope Findings (from Gill Scrapes):
Upon performing gill scrapes on the dying/dead fish, I found that their gill filaments were severely eroded and necrotic. Under the microscope, the gills are covered with the organisms shown in the attached images.
Given that the fish have been in therapeutic copper the whole time and their body surfaces are completely clean, I am deeply confused:
1. Are these Ich (Cryptocaryon irritans) trophonts that are somehow completely confined to the gills?
2. Or am I dealing with a severe infestation of gill flukes (Dactylogyrus) or perhaps the peracute, gill-only stage of Marine Velvet (Amyloodinium)?
3. Could the white dot-like lesions in the gills actually be mucus plugs/tissue necrosis caused by something else, or are they the parasites themselves?
I have access to raw chemical powders including Kanamycin, Metronidazole, Praziquantel, and Fenbendazole. I would deeply appreciate any diagnostics on these microscope images and advice on how to save the remaining fish.

P.S. English is not my native language, so I am using an AI translator for this post. Please excuse any unnatural phrasing or grammatical errors. Thank you for your kind understanding and patience!
Thank you so much in advance!

Welcome to Reef2Reef!

Your images are puzzling. Brooklynella would be more oval shaped. With gill flukes, you will see short worms that twitch and move. Ich trophonts are more common on the skin than on the gills. That leaves velvet, Amyloodinium. However, neither ich not velvet should be able to survive 2.5 ppm of copper power.

How long after the fish arrived did they die? Could the fish have been arriving to you sick? In those cases, Copper Power is less effective at stopping an active infection.

 

[Mr.Yan]

Hi everyone,
I am a marine fish vendor from China, and I've learned a lot from this amazing community. Thank you all so much for the valuable resources here.
Recently, I've encountered a severe crisis with a massive die-off in my quarantine system, and I desperately need your expert help to identify the pathogen.
System and Symptoms Background:
• System: 200-liter commercial quarantine tank.
• Inhabitants: High-density shipment of wild-caught juvenile angelfish (such as Blueface Angels and Koran Angels, around 4cm in size).
• Current Medication: The system is continuously treated with Copper Power (maintained strictly at therapeutic levels, around 2.5 ppm).
• Clinical Signs: Interestingly, there are absolutely no white spots or symptoms visible on the body surface or fins of the affected fish. However, the Blueface and Koran Angels exhibit severe body discoloration and fading (pale skin) before dying.
Microscope Findings (from Gill Scrapes):
Upon performing gill scrapes on the dying/dead fish, I found that their gill filaments were severely eroded and necrotic. Under the microscope, the gills are covered with the organisms shown in the attached images.
Given that the fish have been in therapeutic copper the whole time and their body surfaces are completely clean, I am deeply confused:
1. Are these Ich (Cryptocaryon irritans) trophonts that are somehow completely confined to the gills?
2. Or am I dealing with a severe infestation of gill flukes (Dactylogyrus) or perhaps the peracute, gill-only stage of Marine Velvet (Amyloodinium)?
3. Could the white dot-like lesions in the gills actually be mucus plugs/tissue necrosis caused by something else, or are they the parasites themselves?
I have access to raw chemical powders including Kanamycin, Metronidazole, Praziquantel, and Fenbendazole. I would deeply appreciate any diagnostics on these microscope images and advice on how to save the remaining fish.

P.S. English is not my native language, so I am using an AI translator for this post. Please excuse any unnatural phrasing or grammatical errors. Thank you for your kind understanding and patience!
Thank you so much in advance!

Welcome to Reef2Reef!

Your images are puzzling. Brooklynella would be more oval shaped. With gill flukes, you will see short worms that twitch and move. Ich trophonts are more common on the skin than on the gills. That leaves velvet, Amyloodinium. However, neither ich not velvet should be able to survive 2.5 ppm of copper power.

How long after the fish arrived did they die? Could the fish have been arriving to you sick? In those cases, Copper Power is less effective at stopping an active infection.

Hi Jay,
I’m a huge fan of yours and have learned so much from your work over the years! Thank you for taking the time to reply to my thread.
To clarify the timeline and treatments I did for these fish (Blue Tangs and Blue Ring Angelfish):
1. Day 1 (Arrival): I acclimated them overnight, then gave them a 1-hour formalin bath at 200 ppm, followed by 12 hours of praziquantel at 2.5 ppm.
2. They were then moved directly into a quarantine tank where I started Copper Power treatment.
3. Day 3: The copper level reached 2.5 ppm in the QT.
4. Day 4: I noticed one Blue Tang flashing and rubbing its gills. I planned to repeat the praziquantel treatment on Day 7, to target any newly hatched gill fluke eggs.
5. Unfortunately, on the morning of Day 6, the fish started dying in large numbers, and all were dead by the evening.
I’m trying to figure out what went wrong here, and would really appreciate your insight.
Thank you again!