Red Isopod   12/31/09 Hello, <Hi there Felicia> It's been a while since I've written. I have a question today. I bought a Zoanthid rock today with lots of things on it like mysids, tunicates, etc. One animal I was a little concerned about. I found a few of these red Isopods and I'm worried that they are parasitic on fish. http://img301.imageshack.us/img301/2164/redisopodjz9.jpg <Mmm, might well be... this looks to be a Cirolanid...> I caught one and poked it and blew water on it, but it did not roll up into a ball, so I don't think it is a Sphaeromatid Isopod. It curled ever so slightly, but swam upside down and then righted itself to attach to the wall of the container. It is more red than it appears in the photo, maybe a dark reddish orange. It is about 3 mm in length. Can you tell if it is parasitic from the photo and the description? <Is too likely so... I would stay vigilant... siphon or net out specimens you detect... or pull off of fishes with tweezers if you detect on their sides or in their mouths. Bob Fenner>

Can You Identify This Species?  8/04/08
We posted this image on our site a while back, but recently had a lady inquire as to the type of creature exhibited.
I did a bit of Googling, and found nothing to match, which is because, outside of crabs and lobsters, I'm very ignorant about such things.
We'd love to have someone identify this. If you can, we'll put up your website in the image description along with the name of the identifier.
Thanks in advance!
~ Jason Paschal
P.S. Here's the link to the image on our site:
http://www.imagepoop.com/image/1220/Creepy-Crustacean.html
<Is a deepwater Isopod, maybe Natatolana borealis
Bob Fenner... who didn't copy/post the pic as it is not likely theirs>

Parasite on New Cleaner Shrimp - 2/18/08 Hi, Great website by the way! <Thanks, Ed! It’s a collective treasure, isn't it!> I recently purchased a Skunk Cleaner Shrimp <Lysmata spp.> and I am having some difficulty with it. It is living in my FOWLR tank on its own and there are some things I don't understand. <Alright, let's see if we can't figure them out.> 1) There is a peach coloured, bubble type of growth on the side of the shrimp, is it a parasite or will it go at the next molt? <This is a blood-sucking parasite, generally called a Eucarid or Bopyrid Isopod. We see them occasionally on shrimp, especially in the genus Lysmata (cleaner shrimps). These parasites don’t come off when the shrimp molts and they’re next to impossible to remove without killing the host. The growth you see is actually a female isopod that before it attached, looked like a typical small “roly poly” isopod. These organisms attach themselves to a shrimp, bury under the carapace, and change form into what appears to be a whitish tumor/mass. Color can vary based on the hue of the overlying carapace. The good news is that although unsightly, these parasites do not necessarily kill the host. Nor do they pose a likely threat to any future shrimps in your system. This is because they require an intermediate host, a type of copepod, that isn’t normally found in aquaria. One thing of note however, is that although these don’t actually kill the shrimp by themselves, they can weaken it as well as render it sterile. A shrimp with one of these parasites attached is not going to be as strong as one without. It’s going to be more susceptible to changes in its environment, such as water chemistry, etc.> 2) The shrimp appears to be having some difficulty swimming vertically, and does not get very far before it sinks, could this be because of the growth? <Yes, it’s possible.> 3) I am having trouble feeding the shrimp. I am trying to feed it Hikari small marine pellets, are they correct for a shrimp? <My experience is that they’ll eat just about anything: sinking pellets, small meaty bits of marine origin, flake food, small worms, etc. Just make sure that it’s getting a varied diet.> ..and finally, 4) The shrimp never really seems to venture out when the aquarium lights are on, but as soon as they are switched off begins exploring the tank, is there anything I can do to help this? <This may change as the shrimp becomes more accustomed to its surroundings (as long as no predatory fish are introduced!). Part of this behavior may be a function of its slightly weakened state. For example, when shrimps molt, they instinctively hide because they know they’re vulnerable. Your shrimp could well realize that it’s not a hundred percent and be a bit more cautious. For more information/photos regarding these parasites, please see the following links: http://www.qualitymarineusa.com/article.asp?page=feature&id=968EF63B-2D1D-469A-847A-8E8541B12BE4 http://home2.pacific.net.ph/~sweetyummy42/hitchshrimp.html> Thanks for all your help as I am new to marine fishkeeping. Many thanks Ed. <You’re very welcome, Ed! You’ve come to the right place! Please let us know if there’s anything else we can help you with. Best wishes to you and your little cleaner shrimp. Take care, -Lynn> Re: Parasite on New Cleaner Shrimp -   -02/20/08 <Good morning, Ed!> Thank you for your help regarding my last shrimpy questions, <You’re very welcome!> ..but after reading the articles on one of your links, it appears that the parasite (Eucarid) can be removed from the host shrimp, and that the shrimp will make a full recovery. <Hmmm, yes, it can be done, but it sounds like a potentially tricky (and risky for the patient) procedure, particularly if you’ve never done it before. You’ve got to have a pair of very fine tweezers, or the like, as well as know the anatomy of the shrimp so that you don’t go in at the wrong place. Furthermore, the shrimp is not anesthetized. You’ve got to capture it, turn it upside down and keep it still in that position under water, reach in at the right spot with fine tweezers. taking care not to puncture the body – during which time, the shrimp is most likely trying to get away. I've seen reptiles and sharks enter a sort of catatonic state when they’re upside down. I’m not sure if shrimp react similarly. At this point, you have to determine which is more life threatening – the actual parasite or the removal procedure?> Would you recommend this procedure? <Personally, I wouldn’t do it and wouldn't recommend it. The shrimp can survive with the parasite and there’s little, if any, risk to the rest of the livestock. More importantly, the shrimp is a new addition, already dealing with enough stress. I’m not sure it would survive the procedure.> Many thanks again, Ed <You're most welcome. Take care, -Lynn>

Question about an Isopod in my Tank.
Hi, I have recently cycled my tank and I am noticed tons of these little guys running around my tank.  They seem to hang around the back wall and on the glass.  
<Thus far>
I recently moved and I have all my fish in a 100 g Rubbermaid stock tank for the last 3 months during the setup and cycling of my new tank.  I put 300lbs
of Fiji rock into the tank to start a new system.
I am ready to start adding my fish, but I am extremely worried that I might have the BAD isopods and I do not want to expose my fish to them.
<Me too>
I have some pictures of the creatures as well as a thread I started on reefcentral.com trying to get some information about them.  I got some responses but
nothing definite.  If you could please take a look at the thread, here you can download the images and possible, hopefully let me know if I am ok or not.  
I really want to put my fish into the new system but I don't want to hurt them.  
<Will look>
I know you guys are extremely busy, but if you could take a quick peek and maybe get back to me today that would be extremely awesome!  I met Bob Fenner at a talk he did here in Colorado at Marine Showcase.  I think he would remember me, my company is designing and building the website for Aqua-Medic USA.
<Ah yes, I recall>
Here is the link to that thread:
<A href="http://reefcentral.com/forums/showthread.php?threadid=196239">http://reefcentral.com/forums/showthread.php?threadid=196239 >
Thank you,
John Michael
<I would try a "test fish" here... perhaps a damsel or two... to see if this species of isopod is a "fish eater" or no. Bob Fenner>

Re: Question about an Isopod in my Tank.
Did you find anything out yet? :)
John
<No definitive way (from a pic) to tell the habits of this isopod species... hence the suggestion to try "test fish" at this juncture. Bob Fenner>

Re: Question about an Isopod in my Tank.
Hi, Is it true that only one kind of isopod can roll up like a ball, like a rolly polly bug?
I found this in an article and the kind that can are scavengers.  Mine roll up into a ball.
John
<Do think many can roll up... a defensive mechanism. Bob Fenner>

Sweetlips Isopod
I saw your article "Grunts, Porkfish & Sweetlips" online and your photograph of a Diagramma pictum with a couple of parasitic isopods on its head.  Did you collect any of these isopods?
<No, just took the picture>
  Would you like to have them identified?
  When was the photograph taken?
<In Pulau Redang, Malaysia, about two years ago>
Thank you.
Bert
Ernest H. Williams, PhD, Prof., Dept. Marine Sciences, Univ. Puerto Rico
<Thank you for your interest, offer. Bob Fenner>

Critter IDs Please, with photos attached The first photo is of a worm that looks like a bristleworm, but has some differences.   <agreed... is Polychaetous, but not specifically a "bristleworm".> Have seen this 3" worm on the glass of my 42 gal reef a few times during the day. Doesn't look like a bristleworm because of the "mop" head, and BWs don't usually come out in broad daylight. Photo taken at 4:30 pm, just around feeding time.  There appears to be no damage to corals or fish in the reef this worm is in. <I frankly have no idea what this worm is but am comfortable that most are overwhelmingly safe if not useful as scavengers. You might send that pic to Dr Ron Shimek over on ReefCentral.com (he has his own forum)> The last three photos are of three bugs we sucked out of a well established 72g reef in which had recently lost all our new fish, mostly dwarf and larger angels.   <my friend... please (!) do be careful. Watch your own hands in this tank. They are parasitic isopods and actually can nip/bite you. We have some data on our wetwebmedia site about them as well as in our Reef Invertebrates book. Much abroad on the net too about them. Treatment is possible but an effort> Ammonia, nitrite and nitrate in the tank at the time of the last fish death were 0 ppm.  Had the flashlights out the other night and these bugs were swimming about near the front glass, though some were walking on the sandbed at times. Looks like some kind of isopod, but I cannot say for sure from all the research I've done if they are parasitic or not.   <they appear to be to me> The bugs were about 1/8th of an inch in length when first caught. Have since set up a 5g tank with LR, sandbed and macroalgae from reefs that do not contain these bugs and have added a green Chromis to determine if the bugs will infest the fish.  Over the week the fish has been in the 5g, the bugs have grown twice their original size, have been seen on the glass and sandbed, and the Chromis remains healthy.   <the Chromis for now may be too small and/or fast> Currently in the 72 gal, at night, there are pinhead sized bugs on the glass that look like the young of the three bugs now in the 5g. Can you please ID the worm?   <I'll call him Joey> Also, can you tell from the photos of the bugs if they are parasitic? <seems so yes> If they are, I imagine a long period of time, say 2-4 months, without fish would eliminate these bugs if they are parasitic and have no hosts. <actually... they are on record going over 6 months and still surviving> It has been 3 weeks since the last fish died.  During the fallow period I am continuing to feed the tank daily to maintain high levels of nitrifying and denitrifying bacteria until the time we will stock the 72g with fish again. TIA for your time and consideration. Beverly <wishing you the best of luck my friend. Anthony>

Satan... is an Isopod?    7/17/07
Bob, I swear, if I believed there was a Satan, I imagine this is what s/he would look like:
http://www.quartzcity.net/wp-content/uploads/2006/10/giant-isopod.jpg
;-)
Sara
<Heeee! Can you imagine being on the deep sea floor bottom with a whole bunch of these ginormous rolly pollies!? No thanks! B>

Re: oh, and good luck, Isopod ID    5/24/07
Good luck finding someone to ID isopods!!! I did a summer of that as fresh marine biology graduate for an environmental survey company.  
And isopods were possibly the worst things to ID. I'm impressed if a layman can get them down to family level by eye; even with a microscope doing much better than genus was often impossible.
Cheers, Neale
<Ah, yes... I sorted and Id'd benthic marine invert.s (mainly errantiate polychaetes) locally for a couple of years as a grad student... Some eye strain now! BobF>

-Possible Isopod issues-   1/20/06
Hello all!
<Hello, Justin with you this evening.>
First of all, THANK YOU so very much for your amazing site!  It is such a wealth of fantastic information,
and is truly (in my humble opinion) the best wet-pet resource on the web!
<Well its all due to many people who help, and the crew here. Ill pass your thanks on to Bob.>
I currently maintain a 120G fish-only tank.  In addition to the 3" puffer (Diodon holocanthus), there
is also a 4" angel (Pomacanthus imperator), 4" lion (Pterois volitans) and a couple of small (1-1.5")
damsels.  Salinity - 1.021, Temp - 80*F, Ammonia - 0, Nitrites - 0; Nitrates - 5ppm.
<An interesting mix, have you seen any aggression out of the Lionfish?  most of the time puffers, and lions may squabble, much to the lions detriment when the puffer breaks off spins or nips fins.  do keep an eye out for long term issues.  You also will probably need a bit bigger tank long term for these guys as all the fish get to 15" + other than the damsels.>
A couple of days ago, I noticed a small white spot medial to my puffer's left eye.  The spot does not
look like Oodinium or ick, but is rather large (2-3mm) and flat.  This morning, I noticed two more ventral
spots... also 2-3mm each, flat, and completely circular!  They do not look like any sort of parasite
that I know of, and it seems very strange to acquire trauma with those manifestations.  Also, the spots are
bright solid white, and almost appear "indented" into the skin.  What on earth could this be? <The indented part seems very odd, as most parasites are bulges outward or bumps. It may be an isopod of some sort that has decided to attach on. they can be fairly easily treated in hypo salinity dips or by using a anti parasite medicine in a hospital tank for a few days.  However, From what you are saying it is hard to give you a definite answer on it.  Can you maybe send in a good photo of the area in question.  It would be much more helpful in identifying the culprit if one exists.  Also herding the puffer into a container and gently rubbing the area to see if it comes off or is an actual indentation may save you further headache here.  My puffer enjoys digging up substrate (I have sand) and little pieces get stuck in the spines and look very odd and are a similar size to what you are saying.  Also mine enjoys playing in the sump return pipe and getting micro bubbles all over him as well.  It could be a benign item like that.>
His attitude is perky as always, and he is eating great!  I am at a loss on this one... any ideas?
<You have me a bit stumped as well on this, but Id check the basics first, and a gentle rubbing of your finger on the area may reveal a simple answer to your concern.  Try watching it for now and see if any more appear or if they disappear all together. I will forward this to Bob for some further ideas.  If you can grab a photograph of the area and send it in as I said above, it may be much more telling.>
Thanks in advance for everything!
Christine
<Thank you for being clear, and including everything tank wise I needed to know to focus on the issue.  Hope we can figure this out.>
<Justin (Jager)>  

SW hitchhiker thing
Hello gang,
<Bryan>
Hope all is well. I have a small 20g tank with a 2-1/2" Taenianotus Leaf Scorpion. Tank parameters are temp: 76-77F, NH3:0, NO2:0, NO3:20, Sal:30. Co-habitants include many Columbellid snails, 2 or 3 Clibanarius hermits, 1-1/2" Mithraculus type crab, Zoanthid polyps, a bundle of Chaetomorpha, and the usual micro/macro tag-a-longs. Filtration is by AquaC Remora and 25% IO water change weekly. The fish did a 4 week QT, no copper, no hypo or F/W
dip. The rest of the tank (including live rock) was directly introduced.
I noted this character on the surface film, 1/8" in diameter resembling a small freshwater Argulus louse. It breaks the surface tension and begins floating downward. I can see a swimming or oscillating motion but the sucker descends in a straight path... until it contacts the Leaf Scorpion and gloms onto the fish's side. The Scorpion reacts by doing its side-to-side thing. By morning, the little arthropod-y thing is gone.
So... Is this little creature familiar to anyone? I realize the description is vague and pictures non-existent but was hoping that it is a common, non-pathogenic fellow. I will also check with Shimek.
Thanks
Bryan
<Is it grey/ish in color... Please see here: http://www.wetwebmedia.com/isopoda.htm.  Bob Fenner>   

Unidentified Creatures, Friend Or Foe? - -05/07/05
Dear WWM crew,
Although I haven't heard back from you with regards to my last e-mail, I did in fact find a picture on-line of my mystery creature and I'm afraid it isn't good news.  It's described as a my isopod although google didn't give me any links when I tried that word.  I've attached the picture to this e-mail.  The website for Tampa Bay Live Rock is where I found this picture and they recommend that you remove it immediately as it will act as a fish parasite.  Do you know anything about these creatures?
<What you have is an "isopod"...I believe the "my" was used to show possession as in "hey!  That's my isopod" <G>.  These organisms are indeed parasitic, have a read here http://www.wetwebmedia.com/isopodfaqs.htm and on the associated links in blue.>
Thank you again for everything that you guys do!
Best wishes, Karen
<Regards, Eric R.>