Fire fish Dark Spot on Side

[Mattgee]

Hi came back today after a night away to find one of my fire fish has a dark spot on his side. Seems to be feeding ok and all parameters were fine when checked on Friday.

All my other fish seem clear and happy.

Have attached a couple of photos to help any ID.

Thanks

 

[Jay Hemdal Verified Community Expert]

When I see a firefish with a spot on its side right there, I first think about a particular copepod parasite that they get. How long have you had the fish? It could be something else, but here is an excerpt that I wrote about this:

The purple firefish, Nemateleotris magnifica has a copepod parasite specific to that species – Serpentisaccus magnificae. Described by George Blasiola in 1979, this parasite is seen on newly imported firefish. The body of the parasite is buried in the flank of the fish, behind the gills, either on one or both sides. When the female copepod develops its egg sacs, these emerge from the fish’s skin as tiny coiled strands. Treatment should not be attempted for this parasite, as the adults are buried too deeply into the body of the fish for physical removal to be done safely, and no known chemotherapeutic will eliminate internal crustacean parasites without also harming the host fish. This copepod is thought to have indirect development with a series of planktonic larval stages, so there is no real concern of the eggs hatching and then fully developing and causing reinfection of the host.

I suspect red firefish have a similar parasite. That said, this could be another issue entirely, it is difficult to see in the pics. One thing to be aware of - the location of this spot, right over the abdomen, means that if it is deeply seated, vital organs will be involved.

Jay

 

[Mattgee]

When I see a firefish with a spot on its side right there, I first think about a particular copepod parasite that they get. How long have you had the fish? It could be something else, but here is an excerpt that I wrote about this:

The purple firefish, Nemateleotris magnifica has a copepod parasite specific to that species – Serpentisaccus magnificae. Described by George Blasiola in 1979, this parasite is seen on newly imported firefish. The body of the parasite is buried in the flank of the fish, behind the gills, either on one or both sides. When the female copepod develops its egg sacs, these emerge from the fish’s skin as tiny coiled strands. Treatment should not be attempted for this parasite, as the adults are buried too deeply into the body of the fish for physical removal to be done safely, and no known chemotherapeutic will eliminate internal crustacean parasites without also harming the host fish. This copepod is thought to have indirect development with a series of planktonic larval stages, so there is no real concern of the eggs hatching and then fully developing and causing reinfection of the host.

I suspect red firefish have a similar parasite. That said, this could be another issue entirely, it is difficult to see in the pics. One thing to be aware of - the location of this spot, right over the abdomen, means that if it is deeply seated, vital organs will be involved.

Jay

Hi
thanks for your reply, I got the fire fish around 5 years ago as part of a pair. They were a decent size when I brought them too.
Will try and get a better photo today but as you know they aren’t the easiest of fish to ask to pose for a photo ! Will I need to remove the fish? Which will also not be the easiest of tasks.

Thanks

 

[Alaeriel]

When I see a firefish with a spot on its side right there, I first think about a particular copepod parasite that they get. How long have you had the fish? It could be something else, but here is an excerpt that I wrote about this:

The purple firefish, Nemateleotris magnifica has a copepod parasite specific to that species – Serpentisaccus magnificae. Described by George Blasiola in 1979, this parasite is seen on newly imported firefish. The body of the parasite is buried in the flank of the fish, behind the gills, either on one or both sides. When the female copepod develops its egg sacs, these emerge from the fish’s skin as tiny coiled strands. Treatment should not be attempted for this parasite, as the adults are buried too deeply into the body of the fish for physical removal to be done safely, and no known chemotherapeutic will eliminate internal crustacean parasites without also harming the host fish. This copepod is thought to have indirect development with a series of planktonic larval stages, so there is no real concern of the eggs hatching and then fully developing and causing reinfection of the host.

I suspect red firefish have a similar parasite. That said, this could be another issue entirely, it is difficult to see in the pics. One thing to be aware of - the location of this spot, right over the abdomen, means that if it is deeply seated, vital organs will be involved.

Jay

As I understand it, the red firefish *is* Nemateleotris magnifica; the purple is N. decora. Did the article include photos of the specimens?
Edit: looked for the article, but alas I no longer have my student access. The first page in the accessible demo mentioned that the visible parasite ovisacs were yellow, so probably something else going on here?

 

[Jay Hemdal Verified Community Expert]

Hi
thanks for your reply, I got the fire fish around 5 years ago as part of a pair. They were a decent size when I brought them too.
Will try and get a better photo today but as you know they aren’t the easiest of fish to ask to pose for a photo ! Will I need to remove the fish? Which will also not be the easiest of tasks.

Thanks

Since you have had the firefish for five years, the copepod is NOT the cause of this lesion, you only see this in freshly imported firefish. That leaves an injury as the next most likely cause.

Jay

 

[Mattgee]

Since you have had the firefish for five years, the copepod is NOT the cause of this lesion, you only see this in freshly imported firefish. That leaves an injury as the next most likely cause.

Jay

Hi

thanks for getting back to me. Fish still has the mark on his side yet seems to be swimming and feeding well so have left him in the main tank for the moment. Will just keep checking him and decide if / when I might need to move him out.