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FAQs on Crustacean Parasites, Diseases 

Related Articles: Crustacean Parasitic Disease, Isopod Crustaceans, Marine Parasitic Disease, Parasitic Worms, Roundworms

Related FAQs: Copepods, Isopods, Parasitic Disease 1, Parasitic Disease 2, Parasitic Disease 3, Parasitic Disease 4, Parasitic Disease 5, Parasitic Disease 6, Parasitic Disease 7, Parasitic Marine Tanks, Parasitic Reef Tanks, Cryptocaryoniasis, Marine Ich, Marine Velvet Disease Biological Cleaners, Fish Worm Diseases 1, Treating Parasitic Disease, Using Hyposalinity to Treat Parasitic Disease, RoundwormsTang Health/Disease

"The horror, the horror!"

Parasitic isopods in pufferfish     3/8/17
Hi all,
Recently I bought a blue dot Toby puffer that seemed to have a mild goiter.
It was in a copper-treated quarantine (2.5ppm plus hypo at 1.015) for the last two weeks and seemed to be doing fine, albeit a little sluggish, but this morning I found it dead. In my experience a dead puffer with a bulge that won't go down is a sign of gill parasites, and lo and behold, a necropsy revealed a pair of gigantic isopods wriggling away inside a very warped gill chamber.
If the copper and hypo didn't kill them, is there anything I can do to help a fish with this kind of parasite?
<Yes. Gone over here: http://www.wetwebmedia.com/crustdisfaqs1.htm
plus read here: http://www.wetwebmedia.com/isopoda.htm >
Toby puffer gill openings are very small in the first place, I wouldn't have been able to pull them out without cutting an opening. I also have to assume this is a rare occurrence or else there would be more literature about treating
them, though this is the second time I've seen them pop out of a dead Toby.
<Mmm; not an uncommon marine fish parasite group... But as the saying goes:
"Successful parasites don't kill their hosts" (generally)>
I've attached pictures of the puffer from when he arrived, plus a photo of the isopods. Thank you for your help as always.
<Welcome. Bob Fenner>

Identify parasite      1/26/15
Hi crew!
I'm in need of professional advice identifying something that has been attached to my clownfish. A little background: this was attached to a clownfish that I've had since August. All of my fish go through a quarantine protocol of tank transfer, followed by a treatment of PraziPro
<Only useful for worms>
then followed by a month of observation in a cycled quarantine tank. All inverts (and anything else wet) goes through 11 weeks in a cycled quarantine tank (not the same as the fish). My reef tank has been running for 10 years.
None of my fish are exhibiting symptoms of any parasites, no heavy breathing, no flashing, piping, appetite is excellent, etc. As a matter of fact my clown fish laid eggs the other day but I saw this thing on her that looks like a skin tag. I did a FW dip in her but it did not come off. I ended up putting her on a dissection tray and pulling the thing off with a pair of tweezers. I took pictures of it on my microscope. The Mag was 4x. It appears whatever it is was killed by the FW dip but I am not able to identify what it is. It doesn't appear to be a fluke, maybe some kind of isopod or amphipod?
<I do think the former... IS a crustacean... appears to have legs that are "all about the same" ('iso')
... Do see WWM re these not-fun rolly pollies... and their control. Likely your physical removal is the end of them here>
Any help would be very appreciated. Thank you. Jennifer
<Do you need help using the indices, search tool? Bob Fenner>

Re: Identify parasite      1/27/15
Yes, I do know how to use a search engine. The attached object looked nothing like the images on that page. The one on my fish was clear, no eyes, or even discernible legs.
<I see the eye, remnants of legs and even eggs here>
It actually looked like a skin tag or a raised scale.
<Could be something else; but my guess is still on an Isopod. BobF>

Helfrichi Firefish Ectoparasite     11/20/14
Dear Wet Web Media Crew,
I am writing to ask for help on ID for an ectoparasite that showed up on one of my Helfrichi Firefish about two weeks from purchasing them.
<I see this in your pic... some sort of crustacean... perhaps an Isopod>
The parasite looks like a pear shaped convex transparent disc that is attached in only one point (the mouth, I assume). Motion wise, it can move on the skin and leaves behind some skin abrasion / superficial ulceration
that heals in a matter of days. I've also noted looking from profile that the parasite undulates it's body continuously. The fish didn't look bothered by the parasite and didn't try to scrape it off.
<For whatever reasons fish hosts don't seem to do that... does seem strange>
As one of the two parasites was located on the head between the eyes, quite close to the brain, I've decided to be proactive in removing them and ask the questions later. The second parasite was attached on one side of the
First step was to remove the fish. I've removed one third of the water to reduce the chance of jumping out of the tank. Then after placing the net in the tank, I've suddenly turned off the lights and the fish was in seconds
in the net.
I've placed the fish in a container with one inch deep tank water and I've covered it with glass and placed an LED light on top to allow me good observation. First I've tried to remove the parasites with fine tweezers.
The fish stayed still and let me try, but it was still impossible. As the parasite didn't show any intention in letting go, I decided to quit trying physical removal and to go for a chemical approach.
<For browsers and possible future events, I'd suggest using a relaxant... a more concentrated solution of MgSO4, magnesium sulfate... poured via a dropper over the parasite/s... ahead of trying removal>
This was done with Cupramine
<Mmm; there are other, better choices... that are less toxic to the fish host, any other life (than arthropod) present. See here: http://wetwebmedia.com/crustdisfaqs1.htm
that I placed in drops, undiluted on the parasite. After this, I syringed water on the skin and the parasites finally dropped. I caught the fish and placed back in the tank. The water in recipient was light blue, I think I've used about 2 ml.s of undiluted Cupramine in 1L of water.
<Yikes; this is a bunch of Cu>
The fish was in the water after adding the copper for maximum one minute.
I didn't notice this parasite on any other Firefish (I have a trio), nor any other fish (only watchman gobies and a Atrosalarias blenny). The wounds on the affected fish healed in a matter of days and the fish didn't show any signs of distress.
<Ah, good>
I need to know if there is a Helfrichi Firefish species specific ectoparasite that fits the description.
<None that I'm aware of, no. Fish crustacean parasites (unlike various worm groups) tend to be more generalized in host preferences>
And more generally, if you've got the knowledge of a ectoparasite as the above as I need to figure out if there is a possibility of further issues with this parasite in the tank (eggs, larvae etc.).
<Mmm; well; there don't appear to be any egg-sacs on the one... So am hopeful there are not intermediate forms in your system. I would not... oh I see you mention below>
The tank is FOWLR, with only a gorgonian frag that can be removed, the only sensitive invertebrate difficult to catch being a pistol shrimp highly guarded by four watchman gobies (A. latifasciata and S. yasha).
My ID would be either a flatworm (fits the shape, color, movement) or a crustacean parasite (fish flea, isopod etc.).
I am attaching a photo of the parasite and the links to four movies (full HD, zoomed, from close distance) with the parasites attached on the fish before removal (please excuse the quality).
https://www.youtube.com/watch?v=qT34itquR4s with the fish in the tank (the parasite on the head is quite visible in this video)
<Very nice>
Please feel free to use any part of the images/ videos if you find them useful for other hobbyists. I am happy to provide the originals if needed.
Thank you in advance for your patience and help!
Kind regards, Andrei C.
<And you for sharing. You have provided much useful information for others use and further investigation. Bob Fenner>


Re: Helfrichi Firefish Ectoparasite    11/27/14
Good morning and thank you for your answer,
As a follow up, the ectoparasite came back. I can now see it on all three Firefish, one having a high number of parasites. They seem more shy and now they hide at night time. Also, they've started scratching against sand. It still seems they are the only affected fish in the tank.
I intend to try and catch all three fish and treat in a separate tank. I need you advice on the medication you think will help me kill the parasite, as physical removal is technically impossible.
<I would use an arthrocide... an acetlycholinesterase inhibitor. Please read here re:
http://wetwebmedia.com/isopodcontr.htm  and
My best bet is still Cupramine in therapeutic doses for a short period (2-3 days), but I would love to use something more fish friendly.
<Do read the above>
Thank you in advance for your advice!
Kind regards, Andrei
<Again; glad to share. Bob Fenner>

Howdy and thanks for sharing    3/27/14
Hi Bob,
<Hey Bri!>
Not sure if you remember me, we met at the New England fish disease symposium. I kept telling you you look like bill Murray.
<Oh yes; certainly...>
I still work at A&M aquatics, and have attached a couple of pictures of a parasite from a green Chromis and dispar Anthias. Just started seeing them the past couple of months.
Hope all is well and warmer than Michigan,
<Is this a copepod? Oh! Am in Cozumel diving w/ my sis... and met quite a few folks from there... -30 degrees last week!? Join us! BobF>

Parasite ID     5/21/13
Good evening WWM crew,
My hippo tang, flame angelfish, and clownfish may be infected <infested> with a parasite that I'm having trouble identifying. I have only seen it a few times on them, but they yawn a lot which leads me to believe it is mostly in their gills. It is about the length of lead in a mechanical pencil (a little smaller actually). I can just barely see it, but I can tell that it is long and narrow, not round. It does not move once attached until a few days later when it disappears. The fish lose a scale or two (turns whitish/clear and falls off) every few days. They have had this condition for a few weeks and the severity is not progressing quickly, so I don't think it is Ich. Any thoughts?
<Mmm, this may (just) be body mucus... some sort of irritation (many possibilities)... causing the fishes to exude>
Might parasitic copepods be this small?
<Can be; yes... but are not oblong, worm-like, unless the host is very large (bill fish, whales)>
 I have tried treating with Chloroquine phosphate and Praziquantel to no effect.
<Again; I'd do what you can to spiff up water quality here; see WWM... water changes, chemical filtrants, RedOx improvement... Unless you get samples, look under a microscope, I would NOT randomly medicate>
 I'd rather not use copper in my tank. Do you think parinox will help?
Thank you for your advice!
<Welcome. Bob Fenner>

Puffer parasite??    12/7/12
We have a new golden puffer for about 4 months now with no issues..
All of the sudden tonight when we went to feed them he had these rice like "parasites" all over his body and one of his eyes.
None of the other fish in the tank have any signs of this and he is acting normal so far.
Any ideas?
<Have tried enlarging some of these "zots" and enhancing the image... They look like congealed spots of body mucus more than anything discrete; not like a live organism. Tetraodonts are quite slimy and often particulates will adhere to them... I'd review what your water quality, any supplements, treatments you've added to the water... and not treat this fish/system in any way. Bob Fenner>

Re: Puffer parasite??    12/8/12
This does not look like any type of debris.. the little rice like things look to be alive.. they are very hard to photograph through acrylic.. but see if this helps..
You can really see a few of them stuck to his eye, but they are also on his body.. he does look to have some sand on him as well, but it is the white/clear looking rice shaped things we are worried about.
Thanks so much!
<Thank you for sending along the larger, better-resolved image. BobF>
HERE YOU CAN SEE THEM.....Re: Puffer parasite??    12/8/12
Wow.. I hate to send you such a large photo.. but when you enlarge it you can see the eyes on these things.. OH MY what do we have and how can we get rid of them???
<Oh yeah! I do see these now as some sort of parasitic crustacean... Likely an Isopod (Cirolanids maybe)... Please read here re: http://www.wetwebmedia.com/isopodcontr.htm
and here: http://wetwebmedia.com/crustdisfaqs1.htm
Bob Fenner>

Re: HERE YOU CAN SEE THEM.....RE: Puffer parasite??    12/8/12
Bob,.. sorry to be a pest here, but just worried about my puffer..
I've been doing a lot of reading about these pests and a lot of conflicting information..
One said to pick them off like ticks
<Nah... just use an organophosphate remedy... there are a few, covered on WWM...>

 and another said not to because it can cause more damage.. especially since they are on his eyes..
One said freshwater dips won't work.. another said try it... We tried it.. they are still there...
Baiting seems to be a good way, but I have yet to find the article on how to bait them,
<No to this too>
 and they seem very content to be on the puffer as they do not leave when the lights come on..
So how can I get them off of my puffer first... and second.. is baiting the best way to rid them from the entire system?
Thanks so much!
<Did you read where I last referred you? Please do so. BobF>

Can pods attach to saltwater fish?    11/19/12
Hello WMV Crew,
I have an Allardi clownfish and a Neon Goby in my 26 gallon tank which is crawling with tons of pods. My allardi usually sleeps attached to one of the walls and facing upwards, while my neon goby is always seen either on the back wall of the tank or live rock. The weird thing is, from time to time, little white dots can be seen on both allardi and goby. At first I thought they were Ich, but numerous times I've seen allardi shaking the dots off himself, and then I can see the dots swimming in the water afterwards!
<Not Crypt>
 I don't think fish can just "shake off" Ich parasites,
<No; cannot>
 so I'm guessing these white stuff are pods that attached to my allardi and goby when they were sleeping. Can pods really attach to fish? Thanks! -Jae
<Mmm, some can indeed. In fact, the group (Copepoda) has such diversity as to span virtually all nutrition types... There are some quite large/prominent truly parasitic species, many free-living, and some that can/do "cross the line" to chew on fishes, other life when they can. Not generally an issue as long as the fish livestock is healthy. Bob Fenner>

Help with parasite ID   3/17/12
My Hawkfish recently picked up an unwelcome visitor.
It is a very small, about half the length of a grain of rice.
It is brownish, slightly transparent. The attachment point is larger and more solid. It is soft, and flops around in the current, so a bit worm like. It is not like a pill bug, so probably not an isopod.
After reading various WetWebMedia pages, my thought is some sort of parasitic copepod. But I could not find any matching pictures.
Do you have any thoughts?
Picture enclosed.
<I do agree...>

The fish was in the display tank, but it has been removed to a hospital tank. I have tried a Formalin dip with no luck. I will likely try a freshwater dip next.
<Hold this fish in a soft net, with your and underneath, and pull this crustacean out by grasping its anterior end with tweezers near its insertion in the fish, and pulling backward (toward the tail)>
In particular, a key question is if this is a sign of an infestation and if I should be worried about my other fish?
<Likely this parasite has a complex life cycle and with the removal of the one, this cycle should be truncated>
PS: Really enjoyed Bob's talk at BAR last week.
<Me too>
<Welcome. Bob Fenner>

Tiny whitish 'egg' on Banggai fin   4/28/11
Sigh. I quarantined my pair of Banggai Cardinalfish for a month, and put them in my DT yesterday. Now today I noticed something weird on one of them (but not the other).
I can't believe that I missed it during quarantine, but I might have.
On the fin over its left gill, there is attached to the fin a whitish cylindrical thing about 1 mm long and 1/2 mm in diameter.
What is interesting is that it has a slightly smaller version of the same thing attached to the exact same spot on the fin on the right side!
This is definitely not a 'white spot' as in the several diseases. This is an actual object attached to the top end of the fin about 2 mm from where the fin attaches to the body.
I looked through several references of external parasites, including parasitic copepods, and I can't find anything that looks remotely like this.
It is smooth, and I'd almost swear it's an egg, except that it's clearly attached to the edge of the fin in some way.
I hate to stress the fish by netting it and giving it a freshwater bath.
(I don't have any treatment chemicals here, and getting out to get something in the next day or two would be difficult).
Should I try a bath? Or just wait it out? I sure hate to contaminate the main tank, now that the fish is in it!!
Thanks for any advice!
<I've seen these unusual protuberances on different marine fish before, particularly crepuscular or nocturnal species like Cardinalfish and Soldierfish and they appear to be something like a copepod or isopod. Copepods, in particular come in many forms. They may be similar to the ones commonly found on shrimps of the genus Lysmata. They do not seem to affect the animals in a way that hinders their normal behavior. The other possibility is that they may be flukes. Both parasites are rather unsightly, though and if large enough, may affect the fishes' equilibrium.
It seems to me that some of these parasites are embedded in the skin while others are loosely attached and might be easily removed...although cautiously! This is merely an opinion based on your description so,
honestly, a photo may be more useful for positive identification!
Good Luck! Send a pic if possible!
Sam Scalz>
Whitish egg on Banggai Cardinal (More information!)    4/30/11

Hi. Sorry for the repetition, but I just got more information. Here is my prior email, with the new information added. Once again, I'm sorry to trouble you with the repeated email.
<No worries. Sam appears to be "out", so I'm responding>
Sigh. I quarantined my pair of Banggai Cardinalfish for a month, and put them in my DT yesterday. Now today I noticed something weird on one of them (but not the other).
I can't believe that I missed it during quarantine, but I might have.
On the fin over its left gill, there is attached to the fin a whitish cylindrical thing about 1 mm long and 1/2 mm in diameter.
What is interesting is that it has a slightly smaller version of the same thing attached to the exact same spot on the fin on the right side!
<More and more curious>
This is definitely not a 'white spot' as in the several diseases. This is an actual object attached to the top end of the fin about 2 mm from where the fin attaches to the body.
I looked through several references of external parasites, including parasitic copepods, and I can't find anything that looks remotely like this.
<Many parasitic ones look nothing like crustaceans>
It is smooth, and I'd almost swear it's an egg, except that it's clearly attached to the edge of the fin in some way.
<Might actually be eggs... as you likely are aware, Apogonids are mouthbrooders... these may be "escapees">
I hate to stress the fish by netting it and giving it a freshwater bath.
(I don't have any treatment chemicals here, and getting out to get something in the next day or two would be difficult).
Should I try a bath? Or just wait it out?
<This last is what I'd do>
I sure hate to contaminate the main tank, now that the fish is in it!!
<Not to panic>
Thanks for any advice!
New info: I put a big magnifier on the tank wall and got a close look at the thing. It is featureless. I looked at many pictures of parasitic pods et cetera, and those pics always show 'creature features' like legs, lobster tail, et cetera. This has no such thing. it is perfectly smooth, featureless, and egg shaped.
In fact, I could almost believe that it is a tumor of some sort, a bulbous thing attached to the fin.
<Not on both sides, no>
And I do find it an interesting coincidence (?) that it has a smaller mate in exactly the same spot on the other side. (The other cardinal has no such thing.)
<The female...>
<Do see the Net re Pterapogon reproduction. Bob Fenner>
Re: Whitish egg on Banggai Cardinal (More information!)    4/30/11
Bob - Thank you for the extended response! An egg? Interesting possibility. I never thought of that.
I am keeping a close eye on it. The fish seems perfectly healthy, swimming happily with its friend and eating voraciously. So I'll just wait and see.
Meanwhile, I'm keeping a close watch on the water. Ammonia, nitrite, and even nitrate are all perfect zeros, so the fish is getting all I can give right now.
I'm discovering something annoying about myself and this new hobby: I may be too much of a worrier to keep fish.
<Mmm, well, on the other hand, It's my long opinion that the hobby is good for "teaching patience" and much more>
Every time I see even the tiniest imperfection in one of them, I imagine the worst and spend the next ten hours searching the web and books for hints about what might be wrong. I'll have to either toughen up or get a new hobby.
<Or more learning perhaps. IF you lived nearby I'd loan you a copy of Ed Noga, "Fish Disease, Diagnosis & Treatment", either edition... and have you read, go through the front section on "trouble shooting". Again, not to worry. Worrying will assuredly not change the future. BobF>

Parasitic Copepod   8/5/10
Hello crew and thanks for all the great advice over the years.
<Thank you Susan>
I Have QT'd 100 lbs of live rock for 4 weeks and have placed it into a new 125 g RR tank with 35g sump that has been cycled for 2 months. I cleaned out the filter sox and found a 4 inch Polychaete and a lot of copepods in the bottom of the sox. After dumping the contents of the filter sox into a bucket I watched two of the round copepods attach to the Polychaete. The Polychaete was immediately in distress. After seeing this I am concerned about what is still potentially in the tank when I start adding fish to the system this weekend. My question is
should I be concerned about this observation?
<Mmm, I don't think I would be. There are probably close to 7500 species of copepods with about 2000 of these being parasitic. Some of these parasitical copepods can be quite large measuring over a foot long. With that being said, it is very rare that a parasitical copepod will find it's way into an aquarium. There are an occasional few that will feed on corals, but rarely any that will affect fish.
Bob may add further input here.> <<Most that do so, "come in" with them on them, and most of these are embedded partly... and removed/removable with tweezers, the intermediate forms if there are any, treatable w/ chemicals toxic to crustaceans... posted on WWM. The more free-living species are best treated chemically, and the more "embedded" ones tend to be quite species-specific. RMF>>
The QT process will only eliminate those organisms that can not find a host in the 4 week time for QT. So I assume there is a good chance that parasitic copepods are present in most systems but only latch onto fish under
certain circumstances. Please let me know if this observation is likely to lead to a bigger problem when the fish are introduced.
<The parasites that concern us is a ciliate protozoan known as Cryptocaryon irritans which
leads to Cryptocaryoniasis, a parasitical disease (ich) which usually proves fatal if not treated promptly.
These Protozoans in their free swimming stage are not visible with the human eye. Your method of QT
should eliminate any of these life threatening Protozoans if present.>
Thanks again for your help.
<You're welcome. James (Salty Dog)>

Re: HELP female Crosshatch Trigger carrying parasites? 7/29/10
Dear WWM Crew,
I have had a 6-7" male Crosshatch Trigger in my QT for 3 weeks now and I decided to pair him up with a female so I got a 6" female on past Tuesday.
I divided the tank in the middle with egg crate so he wouldn't harm her since I want them to check each other out for the duration of the QT and because a 55 gallon may not give her enough room to hide.
After drip acclimation, I put her in and minutes later I see a hundred or so tiny things swimming all over. I do have some LR in the QT so what could these little things be? The swim erratically and under magnifying glass, they looked like they had eyes and oblong shape with a tiny bit of color towards one end.
<Mmm, sounds like Trematodes, flukes... Actually quite common, generally not-too-deleterious parasitic worms of marine fishes. Not hard to treat...
Please read here: http://wetwebmedia.com/fshwrmdisflukef.htm
and the linked FAQs files above>
Is it some parasitic hitchhiker that came with my female or some invert had babies from the LR?
<On the Xanthichthys themselves almost assuredly. Trematodes tend to be pretty species-specific>
Sorry, too small to photograph and they are now all dead anyway since they got sucked up into the hang on back filter. If parasitic, what treatment do you recommend?
<See the referred files>
Also, how do I know when to take out the divider?
<When you can be there to observe these fish full-time>
I have a 300 gallon circular tank that will be ready for fish in 2-3 weeks (going fallow, in it's 8th week),
I plan to put the female in 1st and then the male, leaving them separated till moving them into the 300 tank. Is that smart or should I take out the divider beforehand?
<I would wait, introduce to the main, larger system at the same time... Very likely there will be no problems there>
Thanks.... you guys are GREAT !!
<Welcome. Bob Fenner>
Re: HELP female Crosshatch Trigger carrying parasites? 7/29/10
Dear Bob,
Thank you for your quick reply. I thought flukes detach from the host only when you dip the host in fresh water
<? What? Where did you get such an understanding from?>
so how can it be flukes if I never gave the female Crosshatch a fresh water dip? She went from drip acclimation straight to the QT tank and that's when I saw all the free swimming things. flukes looks more flat right?
<... see the Net or books re>
These things didn't look flat, they looked like some kind of baby invertebrate.
If you still think it's fluke, I do have PraziPro but I want her to be eating before I start the treatment, is that ok since I understand they lose appetite when on treatment. I got her on Tuesday and she still has not eaten.
What do you recommend?
<Keep reading. B>
Thanks again,
Re: HELP female Crosshatch Trigger carrying parasites? 7/30/2010

Dear Bob,
I definitely trust your opinion and after reading up on this subject I started dosing PraziPro in my QT tank.
<Mmm, naught to do w/ trust... Really, the only means of being (more) assured of what these are is microscopic examination. Symptomatically I suggest/ed they might be monogenetic Trematodes... If so, likely a treatment w/ Praziquantel will rid your fishes of them>
Going to do 2 rounds of treatment and maybe even do a Formalin dip.
<Mmm, I'd hold off on the Formalin>
Thanks a lot,
<Welcome. B>

Re: HELP female Crosshatch Trigger carrying parasites?   8/2/10
Dear Bob,
I was able to catch a couple of these free swimming things in the tank. I put them in a glass cup and I first dosed it with PraziPro but that did not kill it.
<Won't kill immediately...>
Then I put then in fresh water for like 4 minutes and that slowed them down but they survived. I can see little legs moving
<?! Not flatworms then>
so I added Methylene blue to the water and that didn't do much either. I'm using a jewelry loupe to look at them from underneath the glass.
So what kills these things?? Formalin 3 baths?
<Formalin kills all forms of higher than viral life... crosslinks peptides>
My female still has not touched any food in QT, I assume that the PraziPro treatment is not working so what next?
<Determining "what" you are dealing with here>
Leaving for vacation in 10 days, need to take care of this urgently.
<Photographs... borrow a close up lens, or a dissection 'scope... I use a cheapy QX series for such. BobF>
Re: HELP female Crosshatch Trigger carrying parasites? with PHOTOS   8/2/10
Dear Bob,
Here we go, got pics from using a loupe and a good camera.
<Ah, good>
I hope these are the things I was talking to you about. The Blue is from Methylene blue I used.
Please i.d this bug for me so you can tell me how to treat my female Crosshatch.
<Appears to be copepod-ish... For sure crustacean. Read here:
re organophosphate et al. cures.

Flame angel and clown fish parasite question, reading re ID and more   3/26/10
Hi to everyone! Chris K here (again)
<Howdy Chris>
It seems that I have been writing to you alot <no such word> lately and I do apologize for the bother.
<Not a bother. We are here to help (and inspire) you and other petfish friends and soon to be friends>
A few days ago I noticed what I believe to be some sort of gill fluke?
(parasite anyway) attached to my flame angels gill.
<Really? Can you take a well-resolved image of what you're observing and send it along?>
The flame is eating and acting normal. So I have been waiting a few days to see if my skunk cleaner shrimp or neon gobies would help. This fish is not a new fish, I have added no new fish to the aquarium recently, however I did add a few new corals just before I noticed the critter - its never been a problem before so I wonder if the new coral could be the cause.
The critter appears to be black with what looks like a white tail.
<Mmm, could be a few things... perhaps a parasitic Copepod of some sort>
Today I notice another one on his other side.
I am wondering what if anything I should do at this point- because I don't think the cleaner shrimp is handling the situation very well.
<May be too big, distasteful for its removal>
The flame is still colorful, active and eating like a pig. I would like your advice on the best thing to do at this point - because I am pretty sure its going to involve tearing my tank down to catch the little darling.
<I would be reading re the identification of crustacean parasites, perhaps worms as well... and their treatment. If this "tail" is a reproductive process... you may well have many more of these soon>
Also my ocellaris clowns seem to have an interesting symptom. I have noticed that they poop white - but not the long stringy stuff that I would normally associate with a parasite infection, but rather an "explosion" of many (a shocking amount to me) of - shorter stringy white things that look like tiny worms. The "worms" don't appear to be alive, but with the movement of the water who can tell? The clowns seem to be acting quite normal as well.
<A good opportunity re the "Worm parasite" reading again...>
I appreciate any help you can give. Thanking you in advance! Chris K
<Posted. Read here: http://wetwebmedia.com/mardisindex.htm
scroll down to the specified trays, read. Bob Fenner>

Re: Flame angel and clown fish parasite question   3/26/10
Oh thank goodness - Bob I do so much appreciate your response. I have attached two of the best photos that I could get - they are a little blurry - I am going to work on getting a clearer shot - I think you are able to notice the black spot with the white tail hanging off his gill near his front fin in both the photos. (another one smaller one forming on the other side, but too small to get a picture)
<I can barely make this out>
I managed to catch him and give him a fresh water dip - but the thing did not fall off. I am floating him in my aquarium right now, while I get a QT tank set up - do you have any suggestions based on the photos?
Chris k
<Yes... an organophosphate... per where you were prev. referred for Crustacean parasites. BobF>

Lump on yellow coral goby 1/25/2009
Hi there,
How are you?
<Fine, thanks>
I'm just writing (again) to ask about this lump I noticed on my yellow coral goby today. It's on the anal fin (is that what it's called? I'm not too sure...) and it's sort of in a rectangular shape, about 1-1.5mm long.
It sticks out like a lump, and it's the color is very very light brown with a tinge of pink perhaps... definitely not yellow. It looks almost like a skin tag, or a blister. At first, I thought it was from physical trauma since I had read about it in the FAQs a few weeks ago... but then I noticed one or two really tiny black dots at one end of the 'lump', and thought it almost looks like eyes of some sort.
Could this be a parasite attached to my fish?
The fish hasn't shown any symptoms though... and from the size of the lump, I would have thought there would be other symptoms. If anything, over the past two days, my fish has been eating a lot more than before, since it'd seem to be starving until recently. I'm not sure what to do really, because currently I have a threadfin butterfly in my QT (bought it a few days ago) so I don't know if I should put the coral goby in my QT as well.
<Maybe try adding a purposeful cleaner (perhaps a Lysmata species), read here: http://wetwebmedia.com/clnrfaqs.htm
or net the Gobiodon and try removing this spot for closer examination. Bob Fenner> 
Re: lump on yellow coral goby - 1/25/10

Hi Bob,
I managed to net the goby to have a closer look at it. It looked like a worm of some sort that was clinging onto its anal fin. When I pinched it with a tweezers, it started running up the goby's body so I was able to grab it and it came off easily. It had these tiny little shrimp-looking legs though..
<Ahh! Likely a parasitic crustacean of some sort...>
whatever it was. I'll definitely look into getting a cleaner shrimp or something similar once my butterfly's out of the QT.
Thanks for your advice and help!
<Please read here re: http://wetwebmedia.com/crustdisfaqs1.htm

Solicit information and cooperation 12/12/09
Dear sirs, this intended and to greet you, and solicit your cooperation on the following. Recently I was looking the wetwebmedia.com/gobies and I found photographs of gobiids parasitized with copepods. Related with this I need
to known if it is possible to get these photographs for personal use only, that mean for comparison with others copepods.
<I have just looked for these... under both my Crustacean, Copepod pix and Gobioid... Bryaninops loki images, and don't see... have had some very trying issues with my desktop computer recently>
Also , as I am working with the identification of some Pennellidae (parasitic copepods),also I would like to know if it is possible to get samples of that kind of gobiids in order to examine the parasite for comparison wit other pennelids which actually I am reviewing.
<I don't have such specimens myself. I would refer you to Dr. Jack Randall of the Bernice P. Bishop Museum in Hawaii for further referral in turn. I will BCC him here>
Please I´ll be grateful for your answer.
Raul Castro R
Universidad de Antofagasta
Depto Acuicultura

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>

Parasite, Copepod...   2/10/08 Here are some pics of a nasty looking parasite on a Stonogobiops nematodes. The fish is a juvenile, about an inch long. He is very active. Eating very well, and you would never know he has a problem. <"Successful parasites don't kill their hosts"> The parasite has a blood red abdomen, two curlycue's at the top, <Egg sacs...> and what looks like a mosquito's proboscis entering the fish. Looks like a salt water Mosquito! <Is a copepod> I have been trying hard to research this, but have had no luck with identification. From reading all the threads that I could, the two courses of action seem to be, one, cleaner shrimp. And then if unsuccessful, manual extraction with tweezers, in a net, under water. <Mmm, dangerous> The fish is so small, I am afraid to handle him. But if I did remove it manually, I was unfamiliar with the medication to swab on the wound, and where to get it. Any help with identification, and a plan of action, would be appreciated. Sorry if the pics are not in perfect focus. These are the best I can come up with, I took fifty, to get these four. Thank you! Richard PS I put the smallest cleaner shrimp that I could find in the tank tonight. I will keep my fingers crossed. <This is a very good idea... I would "just wait" at this junction... Likely trying to extricate or selectively poison (organophosphate) this crustacean will result in the goby's death... Perhaps it will "cycle off" in time... and there is a good chance that it cannot reproduce in your setting... see the Net re... I would just be patient... it may take months to change... Bob Fenner>

Unusual growth on Purple Tang (Zebrasoma xanthurum) 12/10/07 Hello Crew, <Ron> Thanks for taking the time to review my query! For the first time today, I noticed a dark fuzzy/hairy growth on my Purple Tang (Zebrasoma xanthurum) -- passengers side near the tail. ; ) I have searched the web and WWM but can't seem to find anything that fits the profile of a dark gray/black 'hairy' growth. <Could you send along a well-resolved pic? Oh, I see the links below> Nobody in my local Reef Club (RASOC) had any suggestion either. It seems that most accounts of spots or growths on fish are white, unless it involves black speckles or a generally discolored spot. Perhaps my search query is lacking some keyword. However, I would definitely have to describe this growth as hairy or fuzzy in appearance since it appears to be a cluster of 'hairs'. When I look back at earlier pictures that I have taken, I can see that this spot was there in some form a month ago. It is approximately 2 mm in diameter. It doesn't seem to bother the Tang as far as I can tell. I have an active Cleaner Shrimp and he doesn't seem to be concerned about it either. Here are the best pics I can get of the growth. I am providing a couple of flickr links in lieu of sending pictures that may be too large (hope that is ok). Feel free to upload and post if you desire. http://farm3.static.flickr.com/2022/2098256828_b98c969b7d.jpg  http://farm3.static.flickr.com/2188/2097478823_335152a998.jpg  Do you have any idea what it could be?? If so, would you recommend treatment or merely observation for now? Ron <")))>< Charlotte, NC <Might be a crustacean parasite... looks in outline like a pair/two copepods... A shame to stress this animal by netting, but if the occasion presents itself, I would use two nets, capture this fish and gently try prising off this mark with blunt nose tongs (ask your wife re maybe...). IF there is any sign of blood from doing so, do daub (with a "Q tip") a bit of mercurochrome/Merthiolate/Merbromin on to the spot. I see what appears to be the antennae of a Lysmata sp. in the background... In time, this cleaner may remove this mark... Otherwise, I doubt if it is really debilitating, and strongly sense that it is not "catching". Cheers, Bob Fenner>

Re: Unusual growth on Purple Tang (Zebrasoma xanthurum) 12/10/07 Bob, <RonF> Thank you for the information you provided. The pictures closely represent the view one gets with the naked eye. Perhaps I will try to use my digital zoom to get a closer pic, in order to see if it is indeed some sort of crustacean. I am hesitant to stress the Tang out by netting it, as you alluded. For now, I will observe and hope that the Cleaner ultimately resolves the issue. Ron <")))>< <Ahh! This is what I would do as well. Cheers, BobF>

Parasitic copepods? 10/17/07 Hi there! <DJ> I have been getting some fish in from the Marshall islands and some locally in Hawaii that have these bumps (usually on the fins/tails) of  some fish. Mainly butterflies and tangs - majority yellow tangs. I attached a few pictures of 3 pyramid butterflies that have them (they are in a reef tank after I sent them out) My question is are they something to be concerned about? <Mmm, possibly... as am sure their presence is at least somewhat debilitating... as well as unpleasant to look at> Usually I just rip them off with tweezers or clip them off, but I do miss a lot of them. I don't see them spread or anything, but am concerned about the one butterfly who has them on its side. <Can spread in systems at times...> Thank you so much for the help. Aloha DJ <I would treat the incoming fishes with a dilute freshwater, pH-adjusted formalin bath as spec.ed on WWM... and their intermediate holding systems with an organophosphate... likely DTHP or Dimilin... commercial products of such also spec.ed on WWM. Bob Fenner>
Re: parasitic copepods? -- 10/18/07
Mr. Fenner, <Just Bob, please> Thank you for the quick response. I run my system water (am a wholesaler in Hawaii) <Oh! We may well know some of the same folks... Furry Slippers/RandyF on O'ahu... Mr. Fish/Steve, Dave Dart... others on the Big Island...> with Nitrofurazone and copper (about half dose each) consistently. Freshwater doesn't seem to knock these things off. Would formalin work better? <Yes it would, but the real deal is a dose or three with the pesticide...> My other question is would they spread to other fish in a closed system? <Possibly... though most worm and crustacean complaints tend to be more species, genus, to family specific... Also depends on how simple/complex the critters life cycles are... I suspect these may be direct... i.e. not require an intermediate host> The 3 butterflies are in with some wrasses and tangs. I just don't want them to spread and take over. <Agreed...> Thank you for the reply Aloha DJ <A hu'i hou! Bob Fenner>
Re: parasitic copepods? -- 10/18/07
I know Randy and a few others on Oahu. I don't know many on the big island though. Am not a big enough wholesaler to bring in large quantities of fish the big island :) <I see. Say hello to Furry Slippers for me> What pesticide would work best? do you have a link or something where I can buy it? <Please read here: http://www.wetwebmedia.com/crustdisfaqs1.htm and the linked files where you encounter them there> Thanks again for the help.
<Welcome. Bob Fenner>

Things on Goby?   5/9/07 I just received a red banded antennae goby from a distributor, and I noticed that the little guy has two red, sausage looking blobs on either side of his body.  They are not on his head or gills, but rather about halfway down his body, right behind his stomach/intestinal area.  One blob is about a millimeter, the other slightly smaller. They are red, but still semi transparent.  When you look closely, you can see something undulating inside of them.  It is a bottom to top motion, no squirming or writhing inside.  Also, the larger of the two sausages has a small yellowish "string" coming from the top of it. I do not have a camera here (I'm at work) so I cannot attach a picture. <Rats!> I was looking through all our fish books and cannot find an external parasite picture that matches these things.  My question is, any idea what it is? <Yes... very likely either a crustacean or worm parasite... Not uncommon> It almost looks like the little guy's organs are on the outside of his body!  Especially as the two are directly across from each other, one on either side of his body. Any help would be appreciated.  I do not want to put the poor thing in any of our tanks until I'm 110% what it is.  Our quarantine tank is way to big for him, I'd never find him or he'd get eaten by the puffer we have in there.  Thank you! -Erica <Mmm, I suggest serial administration of an anthelminthic (my choice? Praziquantel), and an Organophosphate (something like Fluke Tabs)... Please read here: http://www.wetwebmedia.com/gobydisfaqs.htm re related, cautionary remarks/matters. Bob Fenner>

Blood sucking insect/parasite? SW crust. parasite?   2/3/07 Hi everyone at WWM, <Barbara>   I recently have become addicted to your very useful and informative website, my appreciation to all that goes into it! The following question is the only thing so far I have not found information on in it!   My tank is 30 gals, 32lbs live rock, sg-1.023-1.024, Ammonia-0, nitrites-0, nitrates-15-20 ppm, but I am having luck lowering it with frequent water changes. <Good, one approach> Current occupants are 1 strawberry Dottyback (Pseudochromis), 2 false Perculas, 1 algae blenny, and 1 Flame angel, I realize it is most likely overstocked, <Yes... you are up against psychological and practical limitations... with the Angel, Salarias...> but all are doing very well. I just noticed tonight that my Dottyback has what looks like some sort of "insect" that seems to be sucking on his tail fin, it's body is blue in color and is about 1/8" long. The Dottyback does not even seem to notice it, and is swimming as usual and eating VERY well as always. I assume whatever it is came from in the live rock, which the Dottyback always hides and swims in and out of. I just wanted to know if I should quarantine the Dottyback, do a freshwater dip, etc? <Yes... I would catch this fish (may require removal of all LR...), and physically remove this parasite... Likely either an isopod or copepod... but could be other... and likely leave the wound site as is... unless there is any sign of bleeding... then would quickly daub with a "Q-tip" and a bit of Merthiolate or such...> I couldn't find any information on this particular critter on your site or the web in general. My thanks for any insight you can offer! Barbara <And if possible, practical, perhaps a friend can take a few quick pix... that you might send along. Bob Fenner>
Re: blood sucking insect/parasite follow-up   2/4/07
Hi Bob,   Thank you very much for your quick reply!   A few hours after I noticed it the insect fell off (disengaged?) There is no bleeding, just a slightly noticeable spot where the insect was. If I see it again I will get a picture and forward it. No easy way to describe it other than a blue colored bug! Thank you again for your advice! Barbara <Thank you for this update... I do hope this was an arthropod (not a worm species), separate sexed... consequently not able to/going to reproduce here. Bob Fenner>

Gill problem... Do "we" stay in Iraq or...?   12/16/06 Hi Crew, I have a 10 gallon with a pair of neon gobies (wild caught) that I bought back in July. <Neat> Shortly after I got them I noticed 2 white lines in the gill of one goby. It looks like small sticks of chalk. <Ahh!> This goby does breath much faster than its mate and is slightly smaller. I thought about trying to remove it with tweezers (and got an affirmative from the Crew to try) but never got up the courage. <Is a bit "tricky"... easy to greatly damage the fish host... any bleeding is a very bad sign... best to daub the area with dilute Povidone Iodine...> Anyway, here we are a few months later with everything about the same. They are both very active and eat well. At this point is there any reason to attempt to remove it? Or am I more likely to do more harm than good? <An important, though impossible to answer question... As (if we look) we are often "faced" (if honest...) with similar questions, issues in our lives... "Do no harm" is a useful creed/oath of western doctors as well as would-be earnest aquarists... If the fish in question indeed doesn't appear debilitated, I would leave this likely crustacean parasite be... not likely to spread (as are to a large degree species-specific AND complex in life cycles... Bob Fenner>  

Fish Parasite <copepod>  12/14/06 Hi, <Hello there> Attached is a picture of my Firefish with an attached parasite behind the right fin. <I see it> I was not smart enough or patient enough to follow the quarantine advice from your Marine Aquarist book. I really enjoyed the book by the way.  I find myself rereading it often. I would appreciate any information about this parasite you could give me. Thank you, Paul Hug <Appears to be a Copepod... the trailing "egg sacs" are indicative to definitive. Please read here re: http://www.wetwebmedia.com/crustdisfaqs1.htm I would (gingerly) remove this from the fish using a tweezers... pulling away, toward the tail... with the fish netted, underwater... Bob Fenner>
Re: Fish Parasite   12/14/06 Thank you for the response.  I am hoping you can give me some advise on what to do next. <Okay> I removed the Firefish, Nemateleotris magnifica, from my main tank. I then removed the parasite using tweezers.  The parasite stretched during removal making me think it was a worm.  The '"Thing" on Firefish' letter sounds exactly like mine.  The curlicue description fits. <Mmm, I do wish I would have remembered to include a note re grasping the "worm" (like previously stated this is actually a crustacean)... near, by the head... pulling firmly, though slowly from there... to prevent breaking the Copepod...> I quickly set up a new 10 gallon tank as a quarantine/hospital tank and moved the Firefish and my only other fish, a diamond goby, Valenciennea puellaris, to this new tank. <Mmm, okay... though likely unnecessary... The parasite likely has a "complex" life cycle... requiring the presence of at least another intermediary organism (which is highly likely not present)> My two week old 105 gallon main tank now contains base rock, live rock, sand from another running aquarium, 29 miscellaneous snails, 15 hermits, 2 Cleaner Shrimp (Lysmata amboinensis), and 6 mushroom corals (Discosoma sp.). This tank with some live rock and sand from an active system shows now ammonia or nitrite.  Nitrates are currently 20 ppm (This is a decrease from 1st week at 30 ppm). <Good> This afternoon the Firefish died.  I am pretty sure I stressed it during removal and by the delay in getting it into the new quarantine tank. <Very likely... sorry for your loss> Should I medicate the diamond goby (no symptoms)? <I would not... not worth the further stress, small likelihood that this is something "treat-able">   I assume that leaving the goby in the quarantine tank and leaving the main tank fishless is a good idea. <Mmm... not really necessary> If so, how long would you recommend and should I do anything else to reduce/eliminate the possibility of transmission? <Use of practical cleaner organism/s here...>   Also my quarantine tank was purchase/setup in a hurry so I ended up with a cheap incandescent hood. Is this a problem, other than heat, for the diamond goby? Thank you, Paul Hug <Not a problem. Paul... please do read re Dart Gobies, Microdesmids... most of the species used in our interest really need to be in pairs... Bob Fenner>

Locally Introduced Parasites? - 10/23/06 Hello, <<Howdy>> I hope you can help me. <<I will try>> I have searched your web site for answers with no avail.  I have a 55g SW tank that is about 3 months old.  My fish are dying! <<...!>> I had 4 king fish native to NJ Atlantic Ocean where I live, <<Hmm...there are "several dozen" species of fish with the common name of "kingfish"...I'll take a guess that these are Menticirrhus americanus...an attractive "mottled" species of croaker that gets too large for this tank (over 20") and is also a "subtropical" species not suitable for a "tropical" marine system>> 1 three-stripe damsel, 1 percula clown, 1 ocean crab, 1 star fish, 1 cleaner shrimp, 1 peppermint shrimp and 5 turbo snails.  About 10 days ago I lost 2 of my king fish.  A few days later I noticed hundreds of tiny bugs darting on the tank glass and swimming in the water. <<Normally I would think these to be beneficial and harmless copepods; but I'm guessing you collected the kingfish and the "ocean crab" locally, yes?...and maybe more?...some sand/rubble/rock?>> These bugs also seem to be attaching themselves to the fish at night, especially the clown fish. <<Uh-oh>> The fish have been eating the bugs off the glass and the damsel was pecking at the clown, cleaner shrimp is lazy. Anyway this morning my other two king fish were dead and hours later the clown died.  The damsel seems to have lost his dark black stripes they are turning gray, especially the one down the front of his head. <<Stress>> Also the fish were jerking and sometimes scratching on the coral. The damsel is the only fish left in the tank besides my inverts which are doing fine. <<As would be expected if these "bugs" are a parasitic crustacean>> My water conditions are in the excellent range, no ammonia, nitrates, nitrite and pH and alkalinity is great.  I run a wet/dry filter.  Any help would be great.  Please help me! <<Is it possible you introduced a parasite (collected locally) that has quickly reproduced in your system and attacked your fishes?  You should remove the remaining fish to a treatment tank and let your display tank sit fallow for 6-8 weeks...the inverts should be fine.  As for treatment, whether to use ionic copper or an organophosphate treatment depends greatly upon identifying the parasite (e.g. - protozoan vs. Isopod).  I would probably try the copper treatment (as you would for Ich).  And do have a look here and among the associated links for more clues/strategies: http://www.wetwebmedia.com/parasiti.htm >> Thanks, Laura <<Regards, EricR>>

Fish Lice/leech?   7/4/06 Hello there!!!  I have a question on the fish I just bought about 2 weeks ago.  It is a six line wrasse.  Just about 1 week ago, I noticed an oval shaped patch on the side of my fish.  That little patch even moves around. It tends to stay on the side of the body only.  I have done some research and narrowed it down to either a fish lice or a leech.  I have noticed that when the patch moves or stretches along the fish's body, the fish tend to scratch up against a rock.  The fish is still swimming and eating regularly.   Its very hard to catch this fish for treatment because they are so fast and always darting into caves.  If it is a fish lice or leech, will it eventually kill the fish? <Too possibly so...> As of today, I only see one of these little fish lice/leech.  Do you think there are more in the water column? <Mmm, not likely. If you are fortunate...> If so, How do I treat the main tank? <Can be treated with "economic poisons" that are mainly harmful to non-vertebrate animals... but...> The main tank has corals.  I'm thinking that the only way to treat the main tank is to go without fish (the host), for a long time so those fish lice/leech die off.  Am I correct?  Thank you. <You are correct. Now, if it were me/mine, I would make the concerted effort to remove the live rock, decor, possibly drain a good deal of the water from this system, and gingerly catch this wrasse (using two nets as to not knock off or disturb the parasite into leaving), lift the fish from the water and carefully pries off the louse... likely an isopod, with blunt forceps... and return the fish to the tank, along with the decor... Likely this is an arthropod/crustacean parasite imported with the specimen (you would have seen it, had less problems had you quarantined...) and has had no opportunity, mate to reproduce... Bob Fenner>

Re: High Nitrates in a Fishless Tank  6/5/06... barnacles, alkalinity, sw maint. Lisa, <Mmm, Bob this time> Back again.  It has been a while, I wanted to test the water and just watch and wait to see if I could get it together.   <Okay> The water I have been changing faithfully once a week between 5-7 gallons in a 55 gallon tank and a 29 gallon tank.   <Sounds about right> The 55 gal. has no fish still, just the live rock and inverts which seem to be doing very well.  The Caulerpa is thriving as well as all the inverts.  The sponge is growing and the feather dusters are fine.  We do seem to have a lot of barnacles.  Is there such thing as too much? <Mmm, can be... Cirripedians can be pests/parasites to fishes as larvae...> I just do not like. Going on 12 weeks now after losing all fish... The Nitrates were high and now seem to be stable at 20 ppm (tap water registers 10ppm)  We do not see a lot of waste in the media of the Fluval. <Canister filters can be problematical... transient pollution sources>      Ammonia sometimes shows 0 and sometimes goes up to .25  The nitrites are always 0.  The PH is what really fluctuates.  The last check was between 7.8-8.0   It always seems to drop. <A lack of buffering, restoring chemical make-up... Alkaline reserve>   I am checking the PH on the new water that I am changing out as it is low and actually raise it high to balance out the low PH of the tank. <Good... but need to check the alkalinity, not simply pH> What other suggestions could you recommend.  I am leery of starting over until certain all the water issues are corrected.      <Please read here: http://wetwebmedia.com/marphalk.htm and the linked files above> The 29 gal.  has live rock and 2 damsels.  The water registers 80ppm nitrates, <Way too high>   0 nitrites, 0-.25 ammonia and Ph also fluctuates low in this tank as well.  Any help is greatly appreciated. Sandy <... please learn to/use the indices, search tool on WWM... A link/beginning to nitrates: http://wetwebmedia.com/nitratesmar.htm Bob Fenner>

"Thing" on Firefish I just purchased a Firefish on Sunday, and yesterday, Monday, I noticed that he has something coming out of a hole behind his pectoral fin. The hole is in his "armpit" and there is not one on the other side. This thing is a yellow-white curlicue that comes out, and looks like it goes back into the hole it came out of. It is maybe 1/2 cm long. By curlicue I mean kinda like wood shaving, or piece of sawdust. He is having no problems swimming or eating. This thing doesn't seem to be bothering him at all, but I would like to know what it is and if I can do anything to make it go away. (The way it is shaped, I think it may be a piece of intestine, maybe?) Thank you! <Mmm, my guess is that this is an external parasite... a copepod likely (do put the terms "copepod fish parasite" in Google and look at the "images"... Can be excised with forceps likely... and careful holding while in a net... Bob Fenner> What are those little bugs? (2/24/04) Hi, <Howdy. Steve Allen here>   I hope you have the answer. <I'll try.>  We have a 55 gal. saltwater that has been set up for about 5 months.  All our fish are well, level readings are normal.  Problem is what appears to be lice like parasites on the walls of the tank. <Probably not parasites.> Are they a danger to our fish and how should we treat them. <Most likely no danger at all. If they swim/crawl around, they are almost certainly harmless (actually beneficial) mini-crustaceans known as copepods. "Fish lice" are isopods that hang directly on fish. If they appear to be attached to the wall, they may be some sort of harmless marine worm.>  We also noticed larger white parasites that appear to be snail like with a fan tail, also on the walls of the tank. <Do they move? May actually be a mini Featherduster worm.> Any advice would be appreciated. <None of these are likely harmful. Enjoy the diversity of life in your tank. Read here to be more certain: http://www.wetwebmedia.com/invertidfaq4.htm http://saltaquarium.about.com/cs/pestscopepods/a/aa061200.htm http://www.wetwebmedia.com/copepodfaqs.htm http://www.rshimek.com/Invertebrate%20Key%20to%20Major%20Taxa.htm >   Thank you. <Hope this helps.>

Do White "Hairs" Indicate a Parasite? 4/9/04  BACKGROUND  - Friend broke down tank and gave me a 4" blue tang - The tang has pale pits all over its head suggesting lateral line disease, though the line looks fine <natural sunlight and improved feeding will improve this>  - Tail is frayed and oddly bumpy near its base  - These symptoms have remained constant for 6 months  <hmmm... does not sound likely pathogenic for lasting this long without getting better/worse>  - Behavior completely normal for a blue tang (healthy swimming, appetite, etc)  - I have provided no treatment  - Goby and Banggai Cardinal tankmates exhibit no signs of illness  NEW SYMPTOM  - I just noticed a series of white "hairs" sticking out from his back, directly below the dorsal fin.  <odd>  - These bristles are parallel to each, angled from front to back (like hair blowing in the wind), the thickness of thread, and number about 10.  QUESTIONS  1. What's wrong with this fish?  <not sure by the text description... a clear photo would help. Else do consult a good manual like Untergasser's Handbook of Fish diseases (TFH)>  2. What should I do to help him?  <ID the symptom first before any move or treatment. Get your Quarantine tank ready if needed if its not still running>  Thanks in advance for any relevant info/advice.  - David  <I see that you are form Boston... do check out the excellent local club: The Boston Reefers. They have their own website (slips me now... do a keyword search) and they have a forum on reefcentral.com They are also hosting the national conference this year in September.. an event not to be missed! Anthony>

Parasite on goby? Hello Crew, <Ken> I've got a yellow watchman goby that I've had for about 8 months. About 2 months ago I noticed that it constantly had its mouth gaping, and that there appeared to be a white mass on the lower inside of it's mouth. It was still acting OK and eating, so I just kept my eye on it. A couple of weeks later I noticed that it had a 1/4" rod shaped projection coming from the side of it's face. I'm guessing it is some sort of parasite. <Yes, looks like a parasitic copepod> I tried to catch the fish to isolate it, but had no luck. Since it does not appear to be contagious, I've left the fish in the tank rather than tear the whole thing apart trying to catch it. <These are generally pretty species-specific. Should not spread> The fish still seems to be doing fine, and the white mass in the mouth appears to be gone, but the rod shaped projection has remained about the same. I've attached a photo of the fish that I took several weeks ago when the mass was still evident in the mouth. Can you tell me what the cause of the projection and mass are, and what I should do if anything to treat the fish. Thanks, Ken <If, when the occasion presents itself, do pull this off with forceps. Bob Fenner>

Are there parasites that you can see? <Oh yes... some crustacean parasites of fishes and other aquatic animals are quite large for example... some inches long> After close examination on my aquarium I notices these extremely small moving creatures in the water, some walking on the glass. Under a magnifying glass they almost look like shrimp. Could these be harmful or might they just be something that the fish stirred up in the sand? <Likely nothing to worry about. Please read here re: http://www.wetwebmedia.com/pericaridanfaqs.htm Bob Fenner>

Argulus (marine)  Dear WWM Crew, <Howdy> I have a 225g salt water aquarium which houses a Niger Trigger, Naso Tang and a Zebra eel. The tank is fish only and has a wet/dry filter. My question is regarding Argulus. I believe I have this due to the actions of the Niger Trigger. It noticeably rubs onto rocks and flinches a lot. Yesterday I noticed 3 small oval shaped "lice" looking parasites moving about it's tail and fins. Yes, they are moving around. They are about 0.075" in diameter. It's fins have frayed a little bit but it's color still looks great. The other fish, as well as the Trigger, are still eating VERY hardily. Does this sound like a good diagnosis? <It may be that your fish does have this Branchiuran parasite genus... Do you have access to a microscope?> I want to treat the tank with "CLOUT" but am nervous about putting medication in my tank. I am also concerned with only treating the Trigger because I have read that Argulus lays eggs in the rocks, so dipping the fish is only a temporary fix. Is this true? <Yes> Will CLOUT have any effect on the eel, since it doesn't have scales? How about the wet/dry filter, will there be any damage? <A bit of a risk, but about the best choice for you here... that or "Marine Med Aqua" or other organophosphate containing medications> If CLOUT isn't a good solution, do you have any recommendations? Thank you very much, Lon <I would try treating the trigger in a separate system (hospital tank), by itself if it is the only infested fish of the three... there is a chance that whatever this parasite is (likely some sort of crustacean) that it is so species specific in its use of hosts that it will die off in your main system in a month or so of leaving the trigger out. There is much to relate to you re your present knowledge of quarantine, treatments... Please read through the areas you feel you're weak in on WetWebMedia.com on the Marine Index (Maintenance) and the "Related FAQs" therein. Bob Fenner>

Buggy parasite prob.s in a new marine system Hello bob, <Hi there Nino> I have started my first marine tank. It's now been seven weeks since I have had my tank running. I have two sleeper gold head goby's in my tank and they seem to have small bug parasites attached to their fins. The other fish are doing fine but also where their gills are their seems to be very dark areas. It's hard to tell you in detail as these fish don't stay still enough for me to see correctly. the ph is 8.3 the sg is 1.022 and the water temp is 24 degrees the ammonia is on 0 ppm the nitrate is on 0 ppm. <Can you describe these "big bugs"? Are they grey in color, segmented? Any apparent eyes?> if you are able to give me some help that would be great. As I am at a loss to know what this is. Also there is 20kg of live rock in the tank. thanks Niño <Do you have any "cleaner" organisms in your system as yet? I would study about their use at this point, maybe employ a Lysmata sp. shrimp to clean out the "bugs"... Please read about their use (there's a search tool on the bottom of the homepage: http://www.wetwebmedia.com/ Bob Fenner>

Parasitic crustacean incident? Hi Robert Fenner,  <Salutem dicit> I am writing you because I have a problem of parasites with my yellow and purple Tang, first I saw small sticks in the back part, close to the tail, then I introduced a healthy purple tang, and now the purple tang has the sticks too!!!, all of my other fishes are healthy, only this two tangs have the sticks, the sticks are white, almost transparent, my yellow tang also has small spots in the front part and it is not ich, they do not show any signs of stress, they are colorful and they eat well, my water parameters are acceptable. Any information about this parasites would be great. Thanks. Alejandro Brosig V. <Interesting... the "sticks" do sound like a parasitic copepod... ala the infamous genus Lernaea of pond fishes... can likely be extracted by using tweezers (netting the fishes, holding them gingerly, wet in a net and hand towel) in the direction away from the head... grasping the parasite near its insertion into these fishes... Hopefully this will be the end of the infestation (the sticks are reproductive structures)... if not, the use of the economic poison, DTHP used in ponds may be efficacious (http://wetwebmedia.com/pndparasitcont.htm)... I would remove these adults and hope for the best at this point. Bob Fenner>

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