Cirolanid isopod? Help?

[Donna421]

Apologies... New here. I posted this and then saw this forum. Can't figure out how to delete the other post.

Please help! I believe, based on what research I have done, that this is a Cirolanid isopod. What can I do?

 

[Jay Hemdal Verified Community Expert]

Welcome to Reef2Reef!

Yes, that’s an isopod, I’ve never seen a big parasitic one attached to a fish’s fin before (not a lot of blood there for it to feed on). I’ve seen small isopods that act as micro predators in tanks - hiding in the rocks during the day, but coming out at night to bite chunks out of the fish.
Physical removal is the only treatment for isopods that have had their terminal molt. For isopods that are still growing, you can use a chitin inhibitor like Dimilin.
Jay

 

[Donna421]

Happy update! Caught the Tang, dipped it in freshwater, bugger dropped off immediately! Tang back into tank.

Amazing how large this thing is!

But... Did it have babies? Are there more? Time will tell. Very nervous about that.

 

[Donna421]

Welcome to Reef2Reef!

Yes, that’s an isopod, I’ve never seen a big parasitic one attached to a fish’s fin before (not a lot of blood there for it to feed on). I’ve seen small isopods that act as micro predators in tanks - hiding in the rocks during the day, but coming out at night to bite chunks out of the fish.
Physical removal is the only treatment for isopods that have had their terminal molt. For isopods that are still growing, you can use a chitin inhibitor like Dimilin.
Jay

Thank you for this information! Will look for this chitin inhibitor to try and catch any immature ones! With that treatment, if you know, are there any life forms that are also succeptible to this drug that I may want to set up in a different tak first? Or might I just be setting up a second tank to have the same issue?

 

[Jay Hemdal Verified Community Expert]

Thank you for this information! Will look for this chitin inhibitor to try and catch any immature ones! With that treatment, if you know, are there any life forms that are also succeptible to this drug that I may want to set up in a different tak first? Or might I just be setting up a second tank to have the same issue?

I’ve never used dimilin in a reef tank. I do know that it will harm Arthropoda if they molt. There is another drug used in reefs, Interceptor. I think it also works on isopods, but you’ll need to ask about it on the reef sub forum here, as I’ve never used it myself.
Jay

 

[TeeJay87]

Happy update! Caught the Tang, dipped it in freshwater, bugger dropped off immediately! Tang back into tank.

Amazing how large this thing is!

But... Did it have babies? Are there more? Time will tell. Very nervous about that.

Hey there! Did you have more and do you have any tips for getting rid of them? I discovered one attached to my firefish yesterday and have loads of them in my tank as I caught 20-30ish with a trap last night. Did you try any drugs and would you recommend?

 

[NoahLikesFish]

i wouldnt put a chitin inhibitor in your reef as you will loose all your microfauna. just as good as dumping copper in a reef tank.

 

[Ricky J]

I too am curious. I’ve started a new thread but looking for a good way of catching them. I haven’t had success of pulling larger amounts out at a time. But I keep seeing them on my fish..

 

[Crustaceon]

Hey there! Did you have more and do you have any tips for getting rid of them? I discovered one attached to my firefish yesterday and have loads of them in my tank as I caught 20-30ish with a trap last night. Did you try any drugs and would you recommend?

From the sound of it, I’d keep trapping them.

 

[ScubaFish802]

I almost ran into this but luckily QT'ed my Florida live rock in a bucket first.
Upon finding them I began searching for eradication methods in an attempt to salvage the live rock.

The research on them online is few and far between. The only methods that seemed to work well were very hard on the rest of the tank.

I read a lot of other posts where people seem to have success in hunting/capturing them manually over nightly periods.

Ended up dumping my live rock and not taking the chance

 

[Blue Cheese]

I recently found one in my live rock after quarantining it for months,luckily it was just one so far and never found it on a fish however I have found they are attracted to yellow,a yellow fish to pull and freshwater dip them off and a bottle trap every night with shrimp in it is probably your best way

 

[radav88]

I'm also dealing with this issue. They came in on an order of liverock from TBS at the beginning of August. After trying to introduce my first pair of clownfish this past weekend I noticed a few attach to each clown. I've got a temp tank setup I moved them to while I begin the isopods hunt. Did you have any success with getting them out of your tank?

 

[Blue Cheese]

i fortunately only came across the one,I had the idea of If I had more that I would put a piece of shrimp in my filter sock and turn flow down at night trying to trail some stinky water towards the filter sock to catch them

 

[radav88]

Gonna do some hunting tonight, hopefully only dealing with a small number of them. Thanks for the info.

 

[radav88]

Quick update. Since I've posted this it's been almost three weeks of me hunting these things. I caught probably close to 100 of the in 2 weeks. Then for a week I continued the hunting routine and nothing ever showed. I thought well I finally got them all and put the two clowns back in the tank on Sunday. I kept hunting the last two nights and still nothing. Then this morning I did my morning tank check and there was a big isopod on one of the clown's fin's. This is so frustrating. I'm close to tearing down the rock dunking it all in bleach and starting over.

 

[Blue Cheese]

I would keep at it,if you kill your rock your probably going to regret it in 6 months when your trying to eradicate all the algae that’s going to be on it,where do your clownfish sleep? It sounds like they may be getting hungry and desperate,I also read something from either gulf live rock or Tampa bay rock saying it’s unexplained but all of sudden they just disappear and die off like a seasonal thing too if I remember right and they are trying to figure out the isopod thing and how to deal with them to have better answers for customers

 

[Bucs20fan]

I would keep at it,if you kill your rock your probably going to regret it in 6 months when your trying to eradicate all the algae that’s going to be on it,where do your clownfish sleep? It sounds like they may be getting hungry and desperate,I also read something from either gulf live rock or Tampa bay rock saying it’s unexplained but all of sudden they just disappear and die off like a seasonal thing too if I remember right and they are trying to figure out the isopod thing and how to deal with them to have better answers for customers

What you are referring to is the life cycle, similar to sand fleas. They hatch and grow up, eat, reproduce and die. It would be a period of no isopods and then they would come back if the eggs are not eaten or destroyed.

 

[Blue Cheese]

What you are referring to is the life cycle, similar to sand fleas. They hatch and grow up, eat, reproduce and die. It would be a period of no isopods and then they would come back if the eggs are not eaten or destroyed.

It was just something I read on a thread from a reply of one of the company’s that sold the rock

 

[radav88]

The clowns have chosen a spot high up in a corner to chill at night. I have the flow cranked up pretty high since this is a barebottom setup and will at some point have SPS in it. I think they chose that spot since it's a nice spot out of the flow. Oddly enough, the higher flow makes the isopods alot easier to catch. They come out looking for a meal when I put the shrimp trap in and end up kind of floating around awkwardly since they struggle to swim around and that's when I net them.
The thing that has me most worried is the idea of the isopods reproducing. Now that one got a meal will a few weeks go by and a bunch appear again? The only other life that exists in the tank now are copepods, snails, and algae. I've removed three gorilla crabs, two algae eating crabs, and amazingly a hermit crab hitchhiker that had to have ridden in without a shell. Anyway, I'm going to keep hunting it's just frustrating to see there are still more isopods after I hadn't seen any for a week. Hopefully I'm close to eradicating these things.

 

[Bucs20fan]

Since you are catching all the big ones, you might be in a perfect setup for a sixline wrasse or similar. It stays small and would love to munch on baby isopods. Just food for thought.