Evil Pod's?


Premium Member
Hi Dr Ron

lastnight I had my hand in my tank after lights out. I felt a sharp pain like getting stuck by a needle well I pulled my hand out to find a pod stuck between my fingers without looking at it I killed it but I did have my skin broken by this thing and was bleeding. what kind of pod would do this?
the tank is new no fish no nothing really just cleanup critters and about 75lbs live rock

Thank you

It is likely you were bitten by a cirolanid isopod. Here is a link:

If so, your bite is the least of your problems.

Take a look at the link above and do a forum search (link at the top of the page) here using "cirolanid" as the key term.

These bugs can be real bad news.
Dr Ron
I will be sending you more then a few of these cirolanid isopods. I think I found a safe way to rid my and anyones tank of these that are void of fish.
I was thinking that there has to be a way to trap these things, after all there just stupid bugs right?

well thinking back to sitting on the piers in Hampton bay catching blue crabs I thought it could work kinda the same way for these things.
So what I did is got myself one of my wife's vase's large middle with a necked down opening cut off a hunk of raw fish filled the vase in the tank after lights out then put in the fish.
I sunk the vase into the sand a bit and tilted the opening down to sand level.
wait about 5 to ten min and lift the top of the vase quick and remove from the tank
as of now after about 2 hr's of this I have caught over 100 large ones not counting the tiny babies. all every one is a cirolanid isopod some are very large!
just thought I would share this as it seems to be working great!

Thank you again Dr Ron

I've been bit by one of these guys too. Very tenacious, like it's never been fed. Best I can tell they (it) does not seem to be bother any fish.

Just out of curiousity, is it pronounced see-ro-landid or chiro-landid or neither?


The isopod group called the "Cirolanidae" has over 500 different species in it.

Some are
  • parasites,
  • mostly parasitic, but able to scavenge a meal from carrion,
  • mostly carrion feeders, but they like a good blood meal now and then, and
  • only scavengers.
So, Doug, I suspect you have the ones that are "mostly or partially" scavengers. I think in most tanks these will be able to persist for a long time. I am anxious to see to try to identify them, so I will glad to see what you collect. :D

The ones that are fully predatory or parasitic will NOT come to dead bait.

Good luck!
Thank you Dr Ron!
I will have them in the mail to you on Mon.
and every one in the jar was caught using the above post

Just checking

Just checking

Hi Dr Ron
sorry to drag this up post up again:)
I never got any feedback from you on the Isopods just checking with you to see if you forgot about me:D
thanks again!
Hi Doug,

Not forgotten, sorry for the delay. I have been overwhelmed with tasks at hand, and haven't been able to get to them in detail yet.

And unfortunately, I will be leaving for a speaking engagment tomorrow morning and won't likely get back to you much before early next week.

Again, I am sorry for the delay - normally this doesn't happen when folks send me things, but the last couple of weeks have been very hectic, and some of the more fun tasks (like looking at strange animals) have had to be put off.

The fact that you have many of them, and that they do come to bait indicates they are more facultative predators than some species, and that, in turn, indicates that your system is in less danger from them, so I deferred on their examination until I could get some more time.


I feel sick and I don't even have these in my tank (God I hope not!!!!) ALthough I do have some of those hydroids..the tube type...good luck with those nasty little blood sucking aliens of yours...
Yeah, i've seen these in mine, too. think they came in on the Gulf View rock, but that is what I blame everything on, so I could be wrong (though they did show up the week after:() I noticed them more in the beginning, I haven't seen one in a while. One was stuck on my mandarins face at one point, as if the mandarin had tried to pick it up to eat it, and instead got its mouth sucked on by the nasty creature! I thought it would let go, so didn't bother the mandarin until the next day, I tried to catch the mandarin after seeing the creature on it again, but failed to get him, but in the rush to get out of the way of the net, he managed to free himself of the parasite (thankfully!).

I hope they've starved to death.

Just venting as it is the same issue.
I thought for a long time that I was cutting my hand with corals untill today. Usually I clean my hand with towel after I feel the pain but today I was in the basement and picked two corals from the basement tank to bring them upstairs and felt the pain but could not touch it because I had corals on both hands and when I came to my tank I looked at my hand I saw the pod and blood around it. I thought about grabbing the camera and take the picture but since I saw it I felt the pain more so I killed it and too late for the picture. I will get my macro camera ready sometime and shoot an animation picture of these thing but that is an idea and hope I can get it.
I definitely have an investation. My tank has been set up for 3 months and I found the first one on my clown yesterday. The clown was not doing to well. I was able to gently remove the cirolanid and this mornong the clown is back to normal, but, now my blenny has one. Will this eventually kill the fish?
Hmm... So I guess I have some isopods in my tank as well. Luckily, they are the slow moving non-biting kind. In one of my nanos, they are all over the glass.

I saw two of them fighting one day, only to get knocked loose into the current, and right into the feeders of a near by Bubble coral. Serves them right!! ;)