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Mandarin Disease FAQs: Diagnosis 

FAQs on Mandarin Disease by Category: Environmental, Nutritional, Social, Infectious, Parasitic (see also: Mandarins/Blennies/Gobies & Crypt,), Trauma, Treatment

Related FAQs: Mandarin Disease/Health 1, Mandarin Disease 2, Mandarin Disease 3, Mandarin Disease 4,
Mandarins/Blennies/Gobies & Crypt, Psychedelic "Gobies"/Dragonets/Mandarins & their Relatives 1, Mandarins , Mandarins 3, Mandarin Identification, Mandarin Behavior, Mandarin Systems, Mandarin Compatibility, Mandarin Selection, Mandarin Feeding, Mandarin Reproduction,

Related Articles: Psychedelic "Gobies"/Dragonets/Mandarins, real Gobies & their Relatives,


Kindly request your help. (Marine Fish Disease Mandarin Dragonet - Coral Beauty)    9/24/15
Dear all,
Thank you for all the information in the website, it is amazing how much I've learnt and the enjoyable time I've spent reading about marine tanks and species!
<Ahh; deeply gratifying to realize we have been of help to you>
My issues... A mandarin dragonet and coral beauty have something I can't determine.
<I see these... sores, non-emarginated... in your pix>
8 weeks ago (1 week after buying it) the dragonet had a small bubble on his right part of the head which became something like a pimple and then exploded leaving an open gap.
A few days later the coral beauty had a bit of an injury on side, maybe done by a rock.
<May be>
I was recommended (lfs) to dip of them in Ro/di as suggested 3 times in a span of a week.
<Just the freshwater alone? Not of use; and for browsers, DO NOTE that such water has NO oxygen; needs to be aerated before and likely during dip/bath procedures>
The injuries seemed to get better however two weeks ago I left for holidays and came back 10 days later and found them worse. It seems like something is chewing on the skin.
<Yes; at least bacterial and/or Protozoan involvement likely here>
So I did 10% water changes every day for a week (lfs suggestion) and then treated the tank with Myxazin for 5 days as the instructions said but it didn't seem to work, they also told me to apply a bit of directly to the fish's wound for three straight days which I did however it didn't work as my coral beauty is dead (RIP). The mandarin is eating and active.
I'd appreciate your help to identify the disease or cause so I can treat them properly or prevent it from happening again. Maybe both each fish has is a different case.
Thank you!
Levels after coming back from holidays: (08/09/2015): salinity 1.026, phos 0, no2 1, no3 0, ammonia 0, pH 8, kH 6 ....
Levels after Myxazin (21/09/2015); salinity 1.026, phos 0, no2 .5, no3 10!!!,
<Not a worry>
ammonia 0, pH 8, kH 6 ....
My tank: 40 gallon tank, skimmer, phos reactor, wm Jebao rw14 . no sump.
Livestock: frags ( ZOA's, hammer, pulsing Xenia.), small rbta, 2 fire shrimp, Nassarius and turbo snails, small paired clownfish, mandarin and coral beauty.
Pics attached
<Well; w/o microscopic examination of sampling, possibly culture; one can only guess in these situations.... Which I REALLY don't like. Were it me/mine, I might try lacing foods of use for a few day treatment of Metronidazole... but otherwise would seek to make the environment optimum and stable and hope the Mandarin comes to stasis.
Bob Fenner>

Dear Bob,

For the last three years we have owned a seemingly happy and fat mandarin fish. It was housed in a 110 gal mixed reef tank which was packed with about 75kg of mature live rock. Along with picking food from the rock it would also take frozen food at feeding time, and always looked healthy and alert.

About four months ago we downsized from that aquarium to a 60 gal bow-front tank. When downsizing we got rid of the larger fish but also sold around 40kgs of live rock.

This morning I came down to aquarium and the mandarin was dead! It did not have a pinched stomach and was eating frozen food the night before.

I just wanted to ask in your opinion what could have been a possible reason for this mandarin to die? There was less live rock for it to browse on, but still more than enough to support such a small fish?


Sam P.

Sorry to read of your loss Sam. 'Mysterious' losses are difficult to discern, but it might well be that this fish merely perished from 'old age''¦ Some mandarins are known (in captivity) to have lived a few more years than this, but like Betta splendens longevities, they're rare. I do think that some Callionymids/oids, the group that includes 'scooters' and psychedelic 'gobies', including mandarins do at times pass from eating something they shouldn't have, and this is another possibility. Additionally, I would state that in the higher plausibilities 'cumulative stress' may well have played a role here.

Lastly, I'd make the comment that folks really should replenish a bit of their olde live rock every year or so, particularly if keeping organisms that rely on forage from such like mandarins, many butterflyfishes'¦ By adding or replacing ten-twenty percent of the live rock with fresh.

Green Mandarin.       5/30/15
Hi Dr. I was wondering if you knew what would cause a green mandarin to get small bubbles/blisters under their skin and have trouble breathing.
<Mmm; yes: Exposure to stinging life, adverse chemical/physical conditions in the water, or too much dissolved gas (emphysematosis) from air entrainment... air mixing with water under pressure... as in an air leak around a volute>

I have lost 2 mandarins to these symptoms and cant find much info on it. Both fish were new additions and appeared very fat and healthy in the store.
<Look at your mechanicals, check your water quality, send along a list of livestock. Bob Fenner>

Re: Green Mandarin.         6/1/15
75 gallon tank 6 months old 80lbs live rock 165w led x2. Ammonia nitrate and nitrite are 0. Sg is 1.025 checked with refractometer. Im running a 18w uv sterilizer ,PhosBan reactor
<Ditch this>

a sca 150 skimmer 20 gallon refugium with 4 inch dsb with macro algae. Jebo 25 wave maker 800gph return. I use 0 tds
rodi water instant ocean reef crystals i feed Larry's reef frenzy every other day. Inhabitants are 2 occeralis clowns 1 fire fish goby 1 Tomini tang 1 lawnmower blenny lots of blue led red leg and left handed hermits lots of Cerith Astrea and Nassarius snails a feather duster frogs spawn Zoas Palys
<These last two could be culprits>

Montipora chalices and hairy mushrooms. I do a 25% water change every other week. Sorry for the poor grammar structure typing from my phone and trying to list all i can. But i have tried 2 mandarins both from same store they looked great in the store no pinched stomach or anything. I drip acclimate for 45 minutes and within 3 days they get what looks like bubbles
or blister under their skin. Im at a loss to whats causing it and so is my lfs who is usually pretty good you may know the owner Dexter hill at triad reef critters.
<Mmm; doesn't ring... BobF>

My Mandarin keeps floating to the surface  3/26/13
Your site is great! I have a question about the health of my Mandarin Dragonette. I am very nervous as I am afraid his end is near. My water parameters are all perfect with my PH at 8.3 and my salinity is at 2.3/2.4.
<I understand... but density is stated otherwise... 1.023... a bit lower than natural here. I would raise. See WWM re>
I purchased him a week ago the day he arrived to the LFS. I properly acclimated him and then released him into my tank. My tank is literally crawling with pods, they cover the glass even with the lights on but I have never seen him eat.
<Might well be species of copepods, other crustaceans here that are unpalatable to this fish/species>
 I have never even seem him peck at the rocks. Lately his is not moving, he keeps pinning himself between coral and rocks, If he doesn't he floats to the surface.
<Mmm, a bad sign... esp. w/ Callionymids... what does this portend? Some sort of injury (most Dragonettes are "harpooned" w/ a small dart... yours may have been poked inside, decomposition internally?)>
 The fish tries in vain to keep swimming to the bottom of the tank but just keeps floating back up like he is wearing a life jacket!  He looks to be in good health, good color, eyes are very active... but I know he is starving to death!!
<Mmm, the only real course of action is patience here. Nothing can be done by you... and the fish won't "spread something" to your other stock>
I don't know what is wrong or if I should remove him from the tank and maybe bring him back to the LFS to see if he will survive. I heard it could be a swim bladder issue which relates to bad water conditions/over feeding.
He hasn't eaten anything in over a week so it cant be that... The holding tank he was in at the LFS was filthy and he was sitting at the bottom covered in the gunk, could that be the cause?  What do you think?
<Am sticking w/ my best guess, above... this specimen was "needled" in capture... will hopefully recover spontaneously. Keep the faith. Bob Fenner>
Thank you,

Mandarin Issues, hlth.    12/7/12
Hey crew got another question for you guys. So I've got a 40 breeder with 80 pounds of live rock and 40 pounds of sand. I also have a 6 gallon H.O.B. Refugium with a ton of Chaeto, feather Caulerpa, and grape Caulerpa I mean this thing is packed I also but pods once a month online. Now here's the problem I have a male and female target mandarin pair the females extremely fat but the males really scrawny they used to spawn daily but that was when they were both fat. Now the male has been hanging around on the bottom I was thinking the female was keeping the from eating but they still hang out a lot I was thinking of taking him to the fish store where work and putting him and putting him in a coral flat. But I was thinking was that maybe it more than that like an internal parasite. Any tips or info?
<Could be both, either of the general "causes" you mention here... I would definitely take out about half the rock to make more room, and add a good deal of branching (e.g. Acroporid, Pocilloporid...) stony coral skeleton to provide more habitat and water volume. I might also try adding a combination Anthelminthic (see WWM re) and Metronidazole to foods they accept... and add Spectrum pellets to this mix (highly nutritious, palatable).>
<Welcome. Bob Fenner>

dragonet, hlth. 2/10/11
I'm not sure if this is were I ask questions,
its my first time, but have read many of your posts and it was saved my fish more then once so I thank you for that. but the reason I'm writing is because I have a 55 gallon tank that I personally tested and then had my LFS double check my tests and although I don't know the exact numbers off the top of my head the nitrate was near perfect and most everything else was satisfactory, to above average. I have a pair of fudge clown fish, 2 peppermint shrimp, a skunk shrimp, a reef safe short spine urchin, and about a week ago got a small striped mandarin dragonet, for the first 3-4 days he got fat and healthy and came out of hiding to eat the abundance of pods coming from my refugium, but in the last couple of days I have noticed he has stopped coming out and when we do see him he has started to get thinner and seems to have stopped eating, he also lost his color drastically compared to when we got him. he also has what looks like short, white hair algae hanging from his sides.
<Mmm, reads like this fish may have gotten stung (a Bristleworm, Cnidarian...) or ate something that didn't agree with it. Happens>
I'm extremely worried I got into salt water fish because I saw a mandarin about a year and a half ago and its breaking my heart to see such a beautiful fish in possible pain! I hope you can tell me what's happening and if there's is anything I can do to stop it.
<Mmm, no, unfortunately not. As you relate good water conditions, nothing peculiar re the other livestock...>
Justin Devine
<Just patience here. Bob Fenner>

Another Mandarin Question 1/26/11
Hello WWM crew,
I have been reading through your site about Mandarin Dragonets and have not had any luck finding my particular situation; I am hoping you can help. I have a 90 gallon reef tank that has been set up for well over a year now and prior to that, a 75 gallon reef that housed a Green Mandarin (he was moved to the 90 gallon about 6 months ago). The Mandarin is VERY fat (healthy) and he has been with me for at least a year with no apparent problems. He is housed with a red fire fish,
<Social animals; live "in twos">
1 Regal Tang (aprox. 3"), 2 green Chromis, 2 blue Chromis, 1 Royal Gramma, 1 Watchman Goby w/ Pistol Shrimp, 2 Skunk Cleaner Shrimp, a variety of thriving coral, a green bubble tip (aprox 2") and 1 red bubble tip anemone (aprox 5-6");
<Mmm, I should mention that anemones can/do consume Callionymoids>

both eating and healthy in appearance. My water parameters are: Calcium 490,
<Mmm, a bit high... your Alk., Mg conc.?>
PH 8.5, Salinity 1.025, Nitrates < 12ppm, Nitrites 0, Phosphates 0, <Some is necessary for chemoautotrophs>
Oxygen is fine (forget exact number), Ammonia 0. I regularly supplement Calcium, Strontium (despite a lack of concrete research), and Iodide no more than twice per week. The tank has nearly 120 pounds of live rock, 100 pounds of live sand, a 6-bulb HO T-5 (3 white and 3 actinic)
<I'd replace two of the actinics w/ more "white">
@ 324 watts. SO...back to the fish in question. The past two days, I have noticed my Dragonet has been perching the entire day in one place.
This is not typical of him, as he tends to swim the entire system pecking at the rocks, eating the abundance of Copepods. Additionally, I have noticed that his tail has been covered in slime (I know the release a slime coat when stressed, but this is constantly visible the past 2 days). The only new addition to the tank is a small (2-3") Tiger Serpent Star who naturally, bothers no one.
The fish does not appear to be losing weight and I still see plenty of Copepods all over my glass. Any advice? I'm worried about him....
Thank you,
<Could be a sting of some sort, or summat he ate... these are the two most likely causes. Not much to do re either/both, other than separate. Bob Fenner>

Dead mandarins....can't find the culprit 1/15/11
Hi guys I want to start by saying thank you for all the great info and your hard work.
I have a 125G saltwater fish tank, 3 years old, it has plenty of copepods and amphipods, about 6 inches sand on the bottom and about 80 pounds or more live rock. The parameters:
Salinity 1.024
Nitrites, phosphates, ammonia 0
<Mmm, why 0.0 HPO4?>
Nitrates about 20 now but varies between 0 and 20 (we use a denitrifier)
<Of what kind? What sort of feeder stock?>
I add iodine, essential elements
and liquid calcium once a week.
I had a pair of mandarin gobies that were big and fat eating frozen food and picking stuff of the rocks all day. They never showed signs of distress or sickness. Yesterday they were swimming and acting normal and this morning the male was dead and it seemed like his top fin and tail were damaged (probably a crab got him after he died). The female was on the opposite side of the tank breathing heavily and not swimming at all. Other than that she seemed ok, no damage on the fins or the body. I removed her from the tank and placed her in a specimen holder and she died 10 minutes later. The male seemed to have a large white spot on the side of his body but I am not sure if that was from a coral stink or something trying to eat him after he died.
The other inhabitants are:
2 Banggai cardinals (pair)
a pair of ocellaris clowns
a male and female McCosker's wrasse
1 diamond goby
a pair of lyretail Anthias
1 blue hippo tang
2 garden eels (who seem to eat anything from frozen to flakes)
1 royal gramma (who seems to have some whitish discolorations
<A clue>
on her head that I noticed about 2 months ago but she eats and swims ok- could it be some bacterial infection?)
<Not likely primary>
3 skunk cleaner shrimp
1 coral banded shrimp
1 sally
2 green emeralds
about 20 Nassarius snails
bumble bee snails(6), margaritas(10), turbo(2), Trochus(5)
Corals: 1 elegance coral, 1 hammer coral, 1 frogspawn, 1 green star polyps, xenias (3), 2 toadstool leather corals, many yellow sun polyps, brown polyps, zoos,
1 candy cane and a couple of think<g>s I still have to ID.
I had a green Nephthea that did great for a while but I think he grew and became to big so it started to die off (all the little ones are still doing ok). I noticed the yellow polyps quit opening and they shriveled up so I came to the conclusion it must be the dying Nephthea that's putting some toxins in the water. I removed the Nephthea, put some activated carbon in my refugium and now 3 days later my yellow polyps are back to normal. Could it be possible that the toxins from the Nephthea affected my mandarins?
<Mmm, yes>
Or you think my elegance coral stung them?
<Both? Not likely>
(if so I think it's very weird it got both of them over night and couldn't see any signs on their skin). Should I be afraid that all my fish will have the same faith <fate>? Thanks
<Well... the two most likely categories of probable cause that occur to me are either the supplementation/chemical treatment, including chemical filtrant use, and/or an allelopathogenic effect w/ your Cnidarians as you speculate... No treatment called for... I'd review your maintenance procedures. Bob Fenner>

Sick Mandarin fish? 3/21/10
Thanks for the awesome site. I am constantly checking for all of your great advice. I am concerned that my mandarin fish may be sick. It is a female target mandarin that I purchased a week ago. She was young and thin, but very active and was only in the shop for about 3 days. I put her in my tank where she stayed in a breeder net for the first 2 days with a piece of live rock. Then I let her go, and she went on a feeding frenzy in the tank. She
has filled out a bit this past week. However, the past couple days, she has started opening and closing her mouth very quickly, with her gills flaring.
It is extremely fast. She is still moving and feeding, but not nearly as much. She is spending the majority of the time sitting on the sand in front of the reef. I have also caught her twitching on the sand substrate. It reminds of flicking due to ammonia, but there is no trace of ammonia, nitrate, or nitrite in the tank. All of the other inhabitants are thriving:
Pair of False Percs
Peppermint Shrimp
Numerous Zoas, Shrooms, and xenia
1 large finger leather, candy coral, and a bubble coral
Reef contains red algae and a ton of Chaetomorpha
My reef is in a 55 gallon tank with an 8 gallon sump, and is over a year old. I will be attaching a 6 gallon algae refugium soon.
Here are my params:
Ammonia, Nitrate, Nitrite - 0
pH - 8.1
KH - 180 mg/L
Thank you very much for the help.
- Jason
<Mmm, well, all this could be "normal behavior"... or this fish may have eaten something that didn't agree with it... or it might have been poisoned a bit by the Zoanthids, stung by some other animal here... Nothing really to do but stay observant, be patient. Bob Fenner>
Re: Sick Mandarin fish? 3/21/10

I do have a colony of Zoanthids that are brown and about 1.5-2 inches tall.
The polyps have little hairs coming off the sides. This colony has flatworms on it. Could she be trying to eat the flatworms off of it?
I am willing to remove this colony. As far as an animal stinging her, are you thinking the bubble coral may have done it?
<The most likely candidate here>
I have tried 3 other mandarins in the past, dating back to about 6 months ago. They have each died after about 2 days.
I blamed the first one on a lack of food, since the tank was only 6 months old at the time. The other 2 had plenty of pods available. I can see them crawling on the rocks and in the Chaetomorpha. If this one dies, I may be out of the mandarin hobby. I always thought feeding was the tough part, but this is strange.
Thanks Again,
<And you, BobF>
Re: Sick Mandarin fish? 3/21/10
I just checked on her this morning and she was dead. There is no sign of trauma, so I don't think she was attacked. I think I'm going to cool it on the mandarins and stick to my coral and clownfish.
<This does sound best. Cheers, BobF>

Mandarin... hlth., poss. chewing by Isopods 2/20/2010
Hello all you fine folks at WWM.
<Salud Frank>
I have an issue with my green mandarin that I'd like to get your thoughts on. The mandarin has been my favorite fish for about 10 months now. I originally had him in my 75 but my girlfriend is moving in so in order to save a little space I downsized to a RedSea max 130d (34 gallon total volume I believe) all in one setup. I kept a few pieces of my live rock and about 2 cups of the live sand for this setup to which I added some new live rock (smaller pieces for smaller tank) and a new bag of CaribSea live sand (the black variety). All my water parameters check in at desirable levels.
PH = 8.3
Amm = 0
Nit = 0
Nitrate = 5-10
salinity = 1.025
cal = 420
Anyhow my problem is that since adding the new live rock I have noticed some little critters that resemble rolypolys only smaller.
<Mmm, could be real trouble... most (if this is what they are) Isopods are predaceous... Read here: http://wetwebmedia.com/isopodid.htm>
I dropped in a few shrimp pellets for the mystery wrasse and scarlet cleaner shrimp who made the move to the smaller tank along with the mandarin and as the pellets disintegrated on the bottom these little bugs were foraging thru it and presumably having a meal. I have read about the dreaded isopods on your site and made the assumption that I must have the scavenging type since I have never seen them on any of the livestock.
<Oh! Thus far...>
Well a couple of days ago I noticed my mandarin's lip looked odd and tried to get a better look at it and in doing so noticed that his tale had apparently been nibbled on as well as having a smooth looking tear in it as well as a tear in his dorsal fin. I am wondering if this is due to a parasitic isopod and curious if one has latched on inside his lower jaw causing him to look like he has a fat lower lip.
<Mmm, maybe. This or something else>
I cant get a good look and he is very shy so I couldn't get a picture for reference but he is still swimming around and hunting for food on the live rock as well as chowing down on frozen Mysis and brine shrimp as well as blood worms all soaked in Selcon. He has always been a good eater but almost seems to be eating more. The thought also crossed my mind that he could have been stung by one of my coral frags (sun coral frag, green button polyp frag, and Sarcophyton?)
or a small Aiptasia or some sort of anemone that came in on the new live rock that is clear but don't look like Aiptasia. Anyhow sorry for the long read but I was wondering if you might be able to offer some advice. Any
would be greatly appreciated.
Thanks a lot, Frank
<You've about covered the most promising possibilities. Keep your eyes open here. Bob Fenner>
Re Mandarin hlth., was fat lip, now swollen pooter 3/10/10

Hello again. I wrote to you all concerning my mandarin a few weeks ago. He appeared to have a fat lower lip at the time and I was fearing the isopod was the culprit at the time but also wondered if he might have been stung by something. Well after a couple of weeks his lip appears to be healed of whatever caused his problem but he now has another issue. Related or not remains to be seen. I noticed the other day that his anus appears to be swollen. Almost bulging as if he needs to poo but to no avail. Could this be related to his last ailment and could it be some sort of parasite/worm or bacterial infection?
<Might be something that "stung" its mouth that now it's having a hard time passing... could be parasitic (if this animal perishes, do save the body for necropsy)>
What do you recommend I try to do to help the little guy? Thanks again for your help,
<Nothing other than providing foods, good conditions. Bob Fenner>

Mandarin/Gas Bubble q -- 11/23/2009
Hi Folks,
<Hey Rebecca! JustinN here!>
I have been searching the net as well as your site since last night and into this morning. I am under the impression from my research that my new mandarin has GBD. I had started him out in my 20 gallon quarantine. It was not topped up and the hang on filter was dropping the water about 3 inches to the water surface. I thought nothing of it at the time as I was more concerned about the fish not feeding while in quarantine.
<A valid concern -- many bypass a quarantine altogether with this fish for this reason (though I am of the mindset that if you are going to attempt a mandarin, quarantine is the best place to attempt to wean them onto prepared foods... if it works at all.)>
Aware of their resistance to ich (I know that they are not immune), I decided to get him into the display where he could eat. He did great at first, making himself a little cubby to hang out in and eating off of the live rock. Later in the day I noticed bumps under the skin, not white. I am familiar with ich and did not think that it was ich but panicked and put him back into the quarantine system and corrected the set up flaws. Now I am wondering if he would be better off in the main display?
It has been set up for 2 years now with a refugium in anticipation of this particular fish and houses one yellow tang as well as some corals. 55 gallon with deep sand bed, full of live rock (forgot the actual poundage), 20 gallon sump style refugium with remora skimmer
Rebecca Bray
<A 55 gallon is not optimal for a Yellow Tang, but being that it is the only fish in the tank, it should be ok. Continued correspondence is below...>

Re: Mandarin/Gas Bubble q -- 11/23/2009
Just called the LFS. The remaining mandarin that came in with mine has the same bubbles under the skin. Theirs is listing to one side.
Rebecca Bray
<Sounds like a problem from the get-go -- I would remove this fish before it becomes a major problem or causes issues for your other pet-fish.>

Re: Mandarin/Gas Bubble q -- 11/23/2009
Close inspection of the bubbles with a light and magnifying glass show that there are 3-4 distinct white spheres in each bubble. Snail eggs?
Is that possible?
Rebecca Bray
<Mmm, not real likely, though I don't know a specific identification for you here. I would remove/return this fish to the LFS -- since they are seeing problems on the one in their care, I would be surprised if they tried to argue against this. Good luck! -JustinN>

Re Mandarin with bubbles -- 11/23/09
I was able to get a close up of the "bubbles" early this morning.
( Notice along the edges.) His color darkened up after the light was on awhile. He is still eating and is alert and active. I could return him to the LFS but I am afraid he will just perish there.
<Rebecca, I will send this msg. on for response, but are you able to make a side view image of this fish? Bob Fenner>
Mandarin with bubbles
These are the closest I have to a side view for now. He has become apprehensive of me. let me know if you need better shots.
Rebecca Bray
<Mmm, can't make out much more... because both specimens (yours, the stores) are exhibiting the same symptom, I suspect there is some commonality in how they've been handled... is the raised area part of the lateralis system e.g.? About all that can be done now is provide good care (water quality, nutrition mostly) and wait and hope. These (Callionymids) are tough little fishes, though they appear not to be. Bob Fenner, whose friend Rob Bray owns House of Fins in Greenwich, CT>

Mandarin with bubbles 11/24/09
Thanks Bob. The bubbles are not directly related with the lateralis system. They are scattered about randomly. I am taking a skin scrape with me to Mystic today along with enlarged photos to see if I can
figure anything out with the Quarantine specialist. No relation to Rob Bray but I did have a former intern go to work for House of Fins.
Rebecca Bray
<Ahh... these don't appear to be resultant from gas embolism, and this family of fishes have very reduced gas bladders, so, not likely a matter of too-rapid ascent from collection (this and the other common Psychedelic Gobies are gathered in pretty shallow water... and with little "spears", not chemicals generally...). Bob Fenner>

More re: Mandarin with bubbles 11/24/09
Hi Bob,
<Good morrow (here) Neale!>
> For what it's worth, my guess would be a thicker-than-normal mucous layer collecting bubbles from the water and perhaps silt from the substrate. The question is why is this dragonet reacting thus, and given its behaviour has changed as well, some investigation of environmental conditions, tankmates, diet, etc. may be in order.
<Is a good guess in my estimation... as this group of fishes is remarkably
"slimy"... but having enlarged the original pix as much as I can, these "bubbles" look almost granular in detail... not like a gas at all. If they weren't so apparently transparent, my guess might be that they were "sand grains" attached with mucus.>
Have seen similar with pufferfish (which also have very small scales and thick mucous layers) after doing things like changing out all the substrate in the aquarium. Puffers recover within a day or two, but then they're hardy, adaptable fish that think with their stomachs. May be different with species only marginally tolerant of captive conditions and less inclined to eat adequately.
> Cheers, Neale
<I'll send on this corr. to Ms. Bray. Cheers! BobF>

Re: More re: Mandarin with bubbles 11/24/09
Thanks for the input from Neale. I did a skin scrape today and took it along with my pics to Mystic. They are stumped as well. I did not get a good enough scrape to see anything under the scope (first experience). When I did the scrape however I went over the bumps on the one side and it did not affect them at all so I can't imagine they were collected from the water. (There is silt on occasion.) None of them ruptured. The other mandarin that was delivered to the LFS with mine still has the same symptoms. They came in with whatever this is. He is still alert and very active and eating away at the live brine, Arcti pods, and pods from the main display that I am importing to the quarantine.
<I can't pretend to be an expert on dragonets, so Bob'll want to comment in detail on your observations I'm sure. But if multiple specimens are showing thicker than normal mucous layers, it might be a result of shipping stress; exposure to some noxious chemical somewhere along the line; or else a contagious infection of some sort (what in freshwater fishkeeping tends to get called "Slime Disease"). This latter appears to be some type of protozoan infection (Costia) analogous to Whitespot/Ick, but different, and somehow triggers excessive mucous production that appears as slimy grey patches on the body. The last time I dealt with Slime Disease on freshwater (on a pair of newly purchased Carinotetraodon irrubesco) I performed two seawater dips a day apart on each fish, and treated the tank with a product called eSHa 2000, which treats against various external microbial infections (Finrot, Fungus, etc.) more because that's what I had to hand than anything else. Both puffers got better very quickly; indeed, the seawater dips seem to shift the excess mucous within hours of treatment.
After a few days, both puffers were completely healthy, and while an accident on my part killed the male, the female is still happily swimming about the tank now, three years later. Because freshwater puffers have an extremely high tolerance for salinity, I dipped them for 20 minutes, and this may also have helped dehydrate any external protozoan parasites. In any case, Bob may be able to say whether freshwater dips would be helpful in this case. While I don't imagine a 20 minute freshwater dip would be safe for Synchiropus, some shorter period of time may well be. Cheers, Neale.>

Re: More re: Mandarin with bubbles 11/25/09
Thanks Neale. I've been considering a freshwater dip as well although I know how dangerous they can be for mandarins. I will be interested in Bob's opinion.
<Mmm, not dangerous, but not generally useful for these sorts of complaints>
The only form of "safe" treatment that we could come up with yesterday was elevated temperature and hyposalinity.
<I wouldn't do this either... just time going by, good care... will hopefully see these apparent pinocytic cysts resolve>
I currently have the quarantine at 80 degrees F and I lowered the specific gravity to 1.017 last night. I do believe that I am seeing an improvement this morning. The most noticeable bumps are smaller. He was sloughing off a lot of slime coat this morning but is still as active as ever. I appreciate the continued support from everyone on the site. It's great to have the resource.
Rebecca Bray
<Welcome. BobF>

Re: More re: Mandarin with bubbles 11/26/09
Thanks Neale. I've been considering a freshwater dip as well although I know how dangerous they can be for mandarins. I will be interested in Bob's opinion.
<Mmm, not dangerous, but not generally useful for these sorts of complaints>
<<Thanks for this Bob. I did wonder if the saltwater dips were purely cosmetic, shifting the mucous, and the Puffers recovered under their own steam. Always difficult to know whether it's time or the treatment that
worked! Cheers, Neale.>>
<<In this case the former. BobF>>

Re: More re: Mandarin with bubbles 11/26/09
That sounds like good news. Can I put him back in the main display or may this be parasitic?
<Highly unlikely to be parasitic. I would place this fish in the main display. B>

Re: More re: Mandarin with bubbles 11/29/09
Hi Bob, Well the mandarin went into the main display on Thanksgiving and today we have a full blown ich infestation. It is most apparent on the tang it just didn't present as ich on the mandarin. Shall I quarantine the 2 and let the main go fallow?
<... all need to be moved to treatment>
I seem to have trouble keeping my ammonia under control in the quarantine. Any suggestions?
Rebecca Bray
>Reading. B<

Sudden Mandarinfish death 07/20/09
Dear WWM Crew,
As always, thank you for your great site. Over the 4 years that we have had our reef tank your help and advice has been invaluable!
<Thanks for the kind words.>
I am writing you because our Mandarinfish (Synchiropus splendidus), that had been thriving in our tank for almost 3 years, suddenly died yesterday.
I am not sure how old he was when acquired, but he never really grew any bigger during the time in our tank. This fish was eating and behaving normally yesterday morning, was missing from sight in the afternoon and showed up dead this morning. Over the years, this Mandarinfish had been a good eater. Not only constantly grazing the live rock, but also taking the brine shrimp that was part of the regular food for the other livestock in the tank. In fact, I often feed him directly from a pipette when I was cleaning the tank. This fish did not starve to death. If anything, he was fat.
<I agree. The fish does not look starved...>
Is it normal for these fish to die with no warning signs or symptoms?
Could he have choked on something? Old age? Is there something that I'm missing here?
<I honestly couldn't tell you anything you probably haven't already thought about. Have you added any few fish to the tank, change any parameters? Did the temp drop over night? The problem with these explanations is that you'd think other fish would be affected.>
Our tank setup is as follows:
* 75 G Oceanic reef ready bow front with a 20 G Eco Systems refugium
* Water quality: 1.025 SG, 8.3 pH, 10 ppm Nitrate, 0 ppm Ammonia & Nitrite, 420 ppm Ca, 1470 ppm Mg
* 15% water change every Friday
* 3 feedings per day. Mixture of liquid, frozen & dry foods.
* Livestock: 2 Amphiprion ocellaris clownfish, 1 Zebrasoma flavescens Yellow Tang, 4 Chromis viridis Blue-Green Chromis, 3 Lysmata wurdemanni Peppermint Shrimp, 2 Lysmata amboinensis Cleaner Shrimp and 2 Lysmata debelius Fire Cleaner Shrimp, some blue legged hermit crabs and various corals.
Thanks for your thoughts!!
<I wish I could give you an explanation, but sometimes we just don't know why fish die. This fish might have had some type of illness or parasite that you just couldn't see.>
<Cheers, Sara M.>

Target mandarin, hlth. 6/10/08 Hi, <Hello> I have had a target mandarin for about 8 months now. Recently it seemed to have become less active. It spent about a third of the day lying in the sandbed, and it seemed to have trouble breathing. <Was this fish eating?> This continued for almost a week until last night I noticed it had lost color in its head, it was now white with light orange spots from the gills up. His head was also kind of shriveled up, like it was slowly shrinking or something. He died last night, and when I found him this morning his body was fully in tact except for his head, which looked like it had deteriorated. What was wrong with my mandarin? Was there something I could have done for him? <Without knowing tank size, water parameters and tankmates it is difficult to say why this fish died, however about 8 months to a year is about how long it often takes for these fish to succumb to starvation is captivity so that would be my first guess.> <Chris>

Mandarin dragonet Fin bleached... comp. f' 2/6/08 Hello, I have a problem with my Mandarin. On his front fins he is beginning to get a bleached out look. <I see this> He still seems to move around the aquarium and do his thing but his fins look horrible. It is as if they are rotting, but all of my searches that do with mandarins and fin rot turn up nothing similar to what my pictures portray. Do you know what this is and how to treat it? <Have seen... likely a decolorizing trend due to stress, nutritional deficiency...> I have hat him for one month now. I have had my aquarium set up for four months. I do not think it is out of food because I can still see copods jumping on the rocks. <These copepods may not "have nutritional value" here> It is a 90 gallon reef. With the Mandarin I have a yellow head pearly jaw fish, five blue green Chromis, a yellow tang, two false percula clown fish and two cleaner shrimp. I also have a lot of snails and three hermit crabs (only three because those are the three I am not able to catch.... yet). For corals I have a frogspawn and an Acropora. <Oh! The Euphyllia may have "stung" this fish...> I also have a bubble tip anemone. <Or this... may consume this Callionymid one night> Last week (1/25) I got the clowns and the anemone. That is when I noticed the problem with the fins. Sat (2/5) I did a 15 gallon water change. I have a SeaChem test and it reads 0 ammonia, 0 nitrite 0 nitrate. The salinity is 1.025. Temp is 79-80. Ph is between 8.2 and 8.3. I hope I have given you enough information to help me with this. Attached are a few pictures to help illustrate the problem. Thank you, David <The greater possibility is that this Dragonet was stung... will likely heal (or be consumed)... I would move either the two stinging celled animals or the Psychedelic "Goby"... Bob Fenner>

Dragonet Mandarin, Mandarin Care 12/19/07 Hi, <Hello> I seem to have problems keeping my mandarins alive. The dragonet is acting the same way my spotted mandarin did. He just lies in the bottom of the tank without moving. He is breathing but seems to have problems moving. He shows no sign of damage. We have a 110 gallon tank, with a yellow tang, fox face, 2 clowns, yellow goby, blue damsel. star fish, shrimp, hermit, and snails. All are doing fine. The water is perfectly balanced, calcium and all is good. <Numbers here, "perfectly balanced" means nothing to me.> we do a 10 gallon change of water every week. Do I have to buy special food for the mandarin? <Not realistic to buy what it needs to eat, needs lots of Live Rock to produce the pods that it eats.> Everyone seems to think so. <They are very difficult to feed.> We have had the mandarin for 2 weeks now and it is still quite plump. Thank you for your help Isabel <Need more information, how much live rock do you have, how long has the tank been established, water parameters. Many possibilities here.> <Chris>

Re: Dragonet Mandarin, Mandarin Care 12/20/07 Chris, <Hello> 1. The ph, alk are in the norm according to the color on the paper. (I cant give you numbers). <Ditch the dipstick style tests, they are so inaccurate they are almost worthless, get some dry reactant type tests, they are much better.> I have no nitrates. We did have phosphate but it is now under control. We took the water to a specialized store, and he checked for copper (none) we make our own water using the osmosis thing., calcium (good ). <Ok> 2. I went and bought some baby shrimp which I gave to him right where he was laying, I did it twice so far. <Did he eat this?> 3. I have 95lbs of live rock in my 110 gal tank. We had a 45 gal; for over one year. About 4 months ago we replaced it with the 110. We did keep the same water and live rock from the 45 gal. Thanks, Isa <How long did the first mandarin last? Did you buy them in the same place? Have you seen any of your other fish being aggressive towards it?> <Chris>

Re: Dragonet Mandarin, Mandarin Care 12/24/07 Chris, <Hello> 1. They are not dip sticks, I put water in a little cavity and then I check the color on the identification card that comes with it, <Ah, ok but if they do not give you number values I would switch to a different test.> 2. The little one didn't seem to eat, he just laid there...but he did change places at one point, that actually made me happy. <Not a good sign.> 3. I bought him at a store for the first time. And the other guys in the tank did not attack him. Unless they do it at night when the lights are out. The little one died, so I told my husband that we better wait for 6 months before getting another one, they are fragile. Thanks and if u have any suggestions, pls let me know for future reference Isabel <Best bet is to give the tank some time to mature, and set up a refugium to culture amphipods and copepods which are their natural food.> <Chris>

Mandarin acting oddly 5/13/07 Hi there, <Carrie> After waiting about 1 1/2 years, I purchased a large mandarin male about 3 months ago for my 150 gallon reef/fish aquarium. I had tons of copepods (big fat ones) and a fishless refugium going, so food is not really an issue! I noticed sometime last week, he was not "hunting", but still. I foolishly thought, wow, he must be full, besides he is not thin and was fatter than when I got him! So after another day went by, I was a little concerned as it was just after lights out (timer on tank) he was in his "lightened" phase of sleep colors, but would go up and backwards (kind of like he thought someone was following him if that makes sense) and acting odd. Today, I looked over at my tank and noticed he was at the top of the tank spitting water. I took some pictures to help you out. Behind his eyes are swollen. Do you have ANY clue what this could be? <This fish appears to be "burned", stung by something... likely biological... could be from a bunch of possibilities... Fireworms (come in all sizes), jellies of various sorts... a blundering into a stinging-celled animal...> I put him into the refugium, even though no one was bothering him, just so he could "chill." <Good move> Thanks!
Carrie :)
<I do hope he recovers. Bob Fenner>

Green Mandarin tail Problem 6/20/06 First of all my husband and I have found your site very useful. Thanks for all of the topics and threads. <Glad you've found them... useful> I'm writing because I've had two green Mandarins back to back that have developed something with their back fin or tail. It looks like it was glued together. It would not spread at all. The mandarins could not swim and therefore could not hunt. I lost them both. My husband is part of RASOC <http://www.rasoc.org/> and while at the RASOC/C-MAC Picnic we asked around and could not get any ideas what may have caused this. We have one of Bob's books now and have searched through Wet web as well. I have not been able to get a good idea of what may be causing this. <Mmm, me neither> They are such beautiful animals and so hard to care for correctly. I don't want to purchase another one until I get down to the mystery. We have a 20 gallon refugium loaded with pods attached to our 120 gallon . I'm sorry I have no idea how much live rock we have. I believe we have more than enough.:) Also many people at the picnic are very excited to be hearing Bob speak in February of next year Columbia, S.C. <Oh yes... As stated, don't know what the root cause of this issue is actually... Other than trying your best to pick out specimens that don't exhibit this trait I'm at a loss here. Perhaps someone will "chime in" here with more. Bob Fenner>

Mandarin hiding - 7/7/05 We have a 44 gallon well established tank with a Mandarin dragonette(2 in), 2 false Percs(1 in), a lawnmower blenny(2in), and a longhorn cowfish (2 in, and yes we know he's poisonous, and he will be moving to the 160 gallon when it finishes cycling). <Actually I was thinking this was a very stocked aquarium. No worries though> The mandarin eats frozen food, shrimp pellets, and the copepods, he has been a steady and healthy tank mate for 8 months. <LUCKY. These are very hard to keep in small confines. I would attribute your luck with keeping this animal to the fact that he does eat frozen and pelleted food> Recently when we did a water change we rearranged the rockwork and moved a banded goby to another tank. After the changes (none of which are new, we rearrange fish and rocks often) <Me too.>, the mandarin started spending lots of time hiding under a piece of coral, which is odd behavior for him. <Hmm> He usually is cruising around the tank hunting ignoring all the other fish (and they ignore him also). Is this new behavior something we need to be concerned about? <So very hard to say. I can tell you though, through my observations in the wild, this is not abnormal for mandarin to hide in and around a territory be it rock or coral> All chemicals are good: ammonia 0, nitrite 0, nitrate 30, and pH 8.2. Any ideas? <Unfortunately, there is little I can offer here. As long as he comes out to eat, you keep water chemistry, and other inhabitants don't bother with him, then I would say he is just in an adjusting period.> Thanks for all your great advice. Casey & Lisa <~Paul>

Mandarin Death Hello, <Hi Martin> I have a 50 gallon marine tank which is 2 years old and the love of my life! I have soft corals, gorgonians and some small fish inc neon gobies, clowns, a blenny and starfish. I carry out regular water changes of 20% every 2 weeks with RO water. I test my water regularly and have no problems. Everything seems healthy, however, yesterday, I found my mandarin dead. He had no signs of injury and looked plump and well. I was shocked at his death. He has lived seemingly happy in the tank for just over a year. I am puzzled as all of my other fish and inverts seem absolutely fine. Our electric had to be off for most of the day the day before he died, which the corals didn't like a lot. Could this have caused him to die? I just think it's strange that everything else looks ok. I am very upset as he was my favourite fish, please help! Thank you, Martin. <I wouldn't think a slow drop in temperature would kill it unless it fell below 70. Possible the system ran out of goodies for him to eat. Was it acclimated to frozen food etc. Search Google on the Wet Web, keyword "mandarins". You may find someone else who has had a similar problem. James (Salty Dog)>

Mandarin Goby appearance concerns First, I just wanted to thank you guys for a great informative site. I've read so much lately, but haven't been able to find what the problem is with my mandarin goby. Although, I have quite a few copepods visible in my tank already after only a month of setting up, I've noticed that my mandarin's skin is a bit irregular. I'm not sure if I got him that way, I didn't really pay attention. But after looking at him for a week now, I noticed he has some weird spots on him and also some bubbles on his skin. The bubbles seem like bumps. I can't quite figure out if this is ich, some other disease, or maybe it's normal. I've done quite a bit of reading and it doesn't seem like ich, because I don't see white spots that look like sand, but more like his skin is being rubbed against the rocks and maybe that's what's going on since I have a small tank for a mandarin. He's swimming fine and seems quite active grazing over rocks frequently, breathing fine, and eating I assume since I have ample copepods. I have a 24G nano cube, 30 lbs live rock, 20 lbs live sand, 30 or so hermit crabs, 15 or so snails... <This is way too many hermits and snails... I would remove about two-thirds of both... trade them in?> ...1 peppermint shrimp, serpent starfish, 2 yellowtail damsels (used to cycle tank), mandarin goby, and 1 clownfish. All parameters are normal, water changes done every week. Is this something I should be concerned about? Should I take the mandarin out ASAP? The bubbles are noticeable on the top of its head, side, and bottom. Thanks so much for the help. Perry. <I would not panic... or "do" anything re this fish at this point. Likely will "fix" itself. Bob Fenner>

Scooters Not Scooting! Dear WWM crew, <Scott F. with you today!> My scooter blennies have stopped moving, although they are still breathing and eating food given to them by pipette, they aren't swimming around. They don't seem able to move their tails to move around, but can use their fins. My blue cheek goby was like this 2 days ago, but seems to have fully recovered and is sifting again. I have a180litre (48 U.S gal) tank with a UV, skimmer, LR, and 15x turnover. I have checked my parameters and the water is fine. At the weekend I added a pom-pom crab, making sure not to put any bag water in, and using Myxazin whilst acclimatizing. What could this be? Will my blennies recover like the goby? Could this be a 24hr bug? Thanks in advance, James <Well, James, it's tough to say what it might be. The fact that the fishes are eating is a very good sign, IMO. I'd run some basic water parameter tests, and make sure that there has not been any sudden shift or decline in water quality. These fishes do not take well to rapid environmental changes, so investigate this possibility. It is a bit unusual for these rather active fishes to stop moving around, but I have witnessed this same phenomenon before, and the fishes seemed to "perk up" after a few days and recovered without any complications. I'd keep observing the fishes carefully, make sure that they eat, and monitor water conditions carefully. It may not be a 24 hour "bug", but it could just be a reaction to some minor change in environment....If some sort of symptoms do manifest, take required action. Other than that- just wait it out for a bit and see how they do...Good luck! Regards, Scott F>

What the heck? When arriving home tonight with my new mandarin goby, <study hard to care for that mandarin> I noticed that my yellow tang had a red splinter looking thing hanging off his nose!!! With this I have two questions What should I do about this (parasite??) thing? <unlikely a parasite> And after giving a perfectly healthy goby a hypo saline bath <a scaleless fish...not the best idea> with dip away I noticed white spots on the goby!! Could this be ich or just stress from the move? <if appeared suddenly, bubbles to particles stuck to the excess mucous of an ill-advised hypo saline/freshwater dip (for the record, I love Freshwater dips with tolerant species)> I don't have a Q-tank (slap on the wrist). <with a ruler> But I do have multiple cleaners <cannot effect a cure on full-on infections in captive systems unassisted...just stimulating> (peppermint shrimp, fire shrimp and cleaner wrasse (been alive in tank for 13 months). <put up the peacock feathers when it is five years old. In the meantime, fire whoever has been giving you fish selection advice... some of your choices are a tree-huggers nightmare...hehe> I also run UV on the tank. How long, if it is ich, till my other fish show symptoms. Thank you for your time!!! Jeremy <eh, don't count your tomites before they are hatched...ha! What an opportunity for pathogenic them humor. Unfortunately, it isn't that funny <smile>. Not clear if it is even Ich yet. Maintain stable temperature... feed medicated food (full 7-11 days) and let's go slow...no need to knee-jerk or overmedicate unless it is symptomatically warranted. And look on the bright side...if some fish die because of a lack of quarantine, you will have a hard lesson to learn from ?!? Kind regards, Anthony>

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