Crustacean parasites of fish - help!

Jay Hemdal · Jan 12, 2023

All,

I've been contracted with Coral magazine to write an article on crustacean parasites of aquarium fish (copepods and isopods). I have a really short deadline for this (in five days - ugh!).

I'm interested in hearing from folks regarding their experiences, both good or bad, with controlling these parasites.

One issue I want to hear more about is the micro-predator, the Cirolanid isopod.

I'm also interested in photos - especially clear photos of the firefish copepod parasite, Serpentisaccus magnificae. This is the critter that causes the spiral shaped egg mass that is often misidentified as a "worm". I can pay some fees for good photos.

Thanks!

Jay

MnFish1 · Jan 12, 2023

Have had no issues.

vetteguy53081 · Jan 12, 2023

I at my pet store have had more than one parasitic Isopods. One was on a pakistan Butterfly which came from then. . . O'hare tropicals also know n O'hare imports
The other on a minniatus Grouper which came from segrest Farms, FL. The grouper had it sticking out of its gills and did not make it as I could not get it to dislodge.
On the butterfly, there were two dark circles and I was able to physically pull it off with tweezers. After this was done, the fish never ate but I believe to to the stress of netting and pulling off the pod rather than. . . If I know then what I knew now, it would have been easier to manage.
I remember getting fish that had a red mark on their bodies and it got worse each day and it porgressed until flseh was showing- Could have used seachem back then.
As you know Jay, we had limited medications which were methelyne blue, malachite green, Tetra Oomed, Tetra Cycline, wardleys, Penn Plax and others then came Mardel who had the better stuff dropping a tablet for each ten gallons.
Jay - remember reading SeaScope newsletters?
How times have changed.

Jay Hemdal · Jan 12, 2023

vetteguy53081 said:
I at my pet store have had more than one parasitic Isopods. One was on a pakistan Butterfly which came from then. . . O'hare tropicals also know n O'hare imports
The other on a minniatus Grouper which came from segrest Farms, FL. The grouper had it sticking out of its gills and did not make it as I could not get it to dislodge.
On the butterfly, there were two dark circles and I was able to physically pull it off with tweezers. After this was done, the fish never ate but I believe to to the stress of netting and pulling off the pod rather than. . . If I know then what I knew now, it would have been easier to manage.
I remember getting fish that had a red mark on their bodies and it got worse each day and it porgressed until flseh was showing- Could have used seachem back then.
As you know Jay, we had limited medications which were methelyne blue, malachite green, Tetra Oomed, Tetra Cycline, wardleys, Penn Plax and others then came Mardel who had the better stuff dropping a tablet for each ten gallons.
Jay - remember reading SeaScope newsletters?
How times have changed.

Oh, that takes me way back! I remember O'hare Tropicals back in the mid-1980's when I worked at the Shedd Aquarium! I used to go out there to buy fish. I bought a Clarion Angel from them for around $100 and it lived for many years after I left the Shedd. Gerald Bassleer worked there for a time, and I have his fish disease book. He then returned to Europe, but while he was there, he collaborated with my curator at the Shedd, Roger Klocek (my first fish disease mentor).

Jay

Reefer Dan · Jan 12, 2023

I had 4 cirolanid isopods come in on my live rock. With lots of hunting, etc I was able to get them before I put fish in. The “stinky water” trap didn’t work for me. One actually landed on me and bit me, when I was trying to rearrange the rock work.so that was exciting. This was the biggest I found in my tank.

vetteguy53081 · Jan 12, 2023

Jay Hemdal said:
Oh, that takes me way back! I remember O'hare Tropicals back in the mid-1980's when I worked at the Shedd Aquarium! I used to go out there to buy fish. I bought a Clarion Angel from them for around $100 and it lived for many years after I left the Shedd. Gerald Bassleer worked there for a time, and I have his fish disease book. He then returned to Europe, but while he was there, he collaborated with my curator at the Shedd, Roger Klocek (my first fish disease mentor).

Jay

Roger Klocek - I remember him. he was one of the notables as was Herb Axelrod and schultz.
I too went to O'hare and made purchases. Geralynn was my sale rep

Here are some of my library:

DaJMasta · Jan 12, 2023

I don't know if they were cirolanids for sure, but I had some hitchhiking isopods that were fish parasites that came in with some gulf live rock when I started this current tank. They latched onto a yellow goby that I had early on and could be seen at night swimming around near the glass - primarily in high flow areas, they were strong swimmers. Worth mentioning that the yellow goby would often swim in the front at night, may not be a coincidence.

I dipped the goby to get rid of them (freshwater, pH matched), then spent a few evenings with a flashlight trying to remove the ones I spotted with a turkey baster. I suspect that the banggai cardinals I kept which were awake all night and would try to eat anything drifting around that was of some size helped control the population, but after a couple of weeks I saw no signs of them anywhere and no other fish had them latched on, and it's been like that for more than a year now.

I caught one of the swimming ones (not actually seen on a fish) and took a look under the microscope:

Jay Hemdal · Jan 13, 2023

DaJMasta said:
I don't know if they were cirolanids for sure, but I had some hitchhiking isopods that were fish parasites that came in with some gulf live rock when I started this current tank. They latched onto a yellow goby that I had early on and could be seen at night swimming around near the glass - primarily in high flow areas, they were strong swimmers. Worth mentioning that the yellow goby would often swim in the front at night, may not be a coincidence.

I dipped the goby to get rid of them (freshwater, pH matched), then spent a few evenings with a flashlight trying to remove the ones I spotted with a turkey baster. I suspect that the banggai cardinals I kept which were awake all night and would try to eat anything drifting around that was of some size helped control the population, but after a couple of weeks I saw no signs of them anywhere and no other fish had them latched on, and it's been like that for more than a year now.

I caught one of the swimming ones (not actually seen on a fish) and took a look under the microscope:

Those look like what we call "Cirolanids"

Jay

DaJMasta · Jan 13, 2023

Glad to have a better ID. Worth mentioning as well: the isopods I had definitely were not obligate parasites. They survived a month or more without a host after coming in on the rock, and I saw in the tank even before I added fish (was hoping they were just the scavenging type), meaning that just running fishless likely wouldn't have done anything meaningful to their population.