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FAQs on Mandarins/Psychedelic "Gobies"/Dragonets/ "Scooters" Behavior

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

Related FAQs: Mandarins , Mandarins 2Mandarin Identification, Mandarin Systems, Mandarin Compatibility, Mandarin Selection, Mandarin Feeding, Mandarin Disease/HealthMandarin Reproduction, Microcrustaceans

Dactylopus kuiteri swimming to the surface at dusk        3/6/15
Hi Bob,
<Hey Jan>
I have a gorgeous Orange and black dragonet that was sold to me as Dactylopus dactylopus.
<Ahh; see often in Indo. in muck dives, but not often in the trade>
It is difficult to distinguish between the two if research isn't done very well. So after the fact I came across Dactylopus kuiteri and noticed that mine has an orange mouth and in fact is D. Kuiteri.
<And Rudie's namesake is a much smaller animal>
Be that as it may, I have the fish and am doing all I can to keep it alive. So far it's ok. I'd like to see it gain more weight, but it is active and sifting the sand bed for food. It also eats frozen on occasion.
It has a large supply of pods and lots of live rock in my system. I have noticed that unlike most dragonets this fish doesn't graze on rocks very often, it is more of a bottom feeder, dweller and sand sifter.
<Don't feed on rocks, or get up on them...>
I've observed it closely for weeks now and have noticed that at dusk it swims to the surface. it appears to be looking for food.
It does this every
evening. Why is that? What is it looking for?
<I think (guess) a mate... am sure you have seen the many pix of Synchiropus et al. Callionymids that divers take of these up and spawning>
What can I add to my system
that goes to the surface at dusk? Do pods rise to the surface at dusk/night?
<Some species do>
I know that copepods will go to light when lights are out in my system and in a refugium. Is this what it is searching for? Thank you.
Best regards,
<Do put the words Synchiropus spawning in your search tool and look at pix.... Bob Fenner>

Re: Dactylopus kuiteri swimming to the surface at dusk    3/7/15
Ah, ok. Never crossed my mind it could be looking for a mate. Poor thing.
I've got a pair of green Synchiropus that spawn all the time and a pair of ruby red ones I think are just too young yet. I would love to release this one back into the wild....going back to the indo anytime soon? ;-)
<Was in Bali most of last Sept., not scheduled to haul out till May 2016... you should come w/ us>
so much.
Best regards to you,
<Cheers, BobF>
Re: Dactylopus kuiteri swimming to the surface at dusk... Life, the trade
Oh how I would love to!!! I was a paramedic instructor for the New York City Fire Department and because of my job responded to the WTC attack on 9/11. My pulmonologist informed me a month ago that I could never ever
scuba dive again. I have air pockets in my lungs from the damage and the doctor discovered something in a recent CAT scan. Too small to biopsy at this time.
<Ahh; a shame.... I strongly encourage you to seek other opinions; perhaps there is a repair/remedy>
I was going to take refresher course for SCUBA this summer. We moved to Florida a little over a year ago just so I could be closer to the ocean and get more involved in the hobby. Then I received this news. My lungs are damaged from all the garbage I inhaled while I was there the first week helping people the first day and searching through the piles that week. I was very ill on the 5th day and could not return to work. It took 3 different antibiotics and 3 inhalers to get me back to normal. Then I retired. I was also a rescuer at the WTC bombing in 1993 and inhaled all
the smoke while in the stairwell making my way up trying to help people there. My dream of switching careers from pre-hospital emergency care to something hobby related needs to be re-evaluated.
<Am rooting for you.... perhaps some time... a few hours per day.... as a retail clerk, developing into installs and maintenance>
I was about to register to take a certification course this Summer at the University of Florida in aquaculture and disease of warm water fish, but honestly to what end? That would be $6,000 worth of study for which I'd  get
a professional certificate and then what?
<You can see my bio. on WWM; there's academia, research and practical application fields to consider. I went the last route>
for now I have the fb group and I'm helping beginners aquarist get started the right way. It is a nice small group of over 500 people who are serious about being good responsible hobbyist. I'm not looking for numbers as much as quality and character.
<Great news! >
The Journal of Emergency Medical Service (JEMS) did a write up in April of 1993 about the WTC bombing. That's me assessing someone's vital signs on the 34th floor.
<I see>
Sorry for being such a downer. I'd be there in a heartbeat if it were not for the lousy lungs. It would be no fun just watching everyone else. I'm  so honored that you asked. I'm a big fan of yours and of what you do with your
site. I can't thank you enough for the invite and for all you do for all hobbyist. I sincerely appreciate it.
<I have some other medical issues; but thus far have continued to dive travel. I do hope to meet you above and underwater someday. Bob Fenner>

Moving areas of lost color on Green Mandarin       1/24/14
I sent this on the 21st, but wasn't sure if it didn't go through.
<Have retrieved it from (our at times finicky) spam filter file this time>
If you just haven't had time to answer, I really apologize for sending it twice. This site (and the Crew's time) are the most valuable resource for folks like me. Thank you so much for all you do!
<Ah, no; thank you for resending>
Dear Crew,
I have had a female (probably), Green Mandarin for about 2 months. She behaves normally, but on a few fins and her back she has irregular areas of faded color. It almost looks like the pigment has rubbed off leaving behind transparent tissue.
<Actually, this is quite common. I've suspected this is due to these areas regrowing... having less chromatophores in regeneration>
Oddly, the size and placement of these patches changes somewhat from day to day -
getting smaller or larger. I do not believe the Mandarin is starving, I take pictures every week and compare the shots over time and she appears to be as fat as ever.
The tank is a 55 Gallon with about 55 pounds of live rock. For the better part of a year this tank housed seahorses and during that time I regularly added large volumes of copepods, amphipods and some Mysid (that tank no longer houses seahorses). My night vision camera reveals lots of amphipods and things that look like Mysid shrimp running around at night, I assume I still have a good supply of copepods, but I add about 1,000 every 6 weeks.
In addition to the Mandarin, I have a small Kole Yellow Eye Tang, a Sailfin Tang,
<Will get/grow too large for this setting>
 a Yellow Wrasse (eats lots of pellets) and two Ocellaris Clownfish (the tangs get along fine and are eating plenty as soon as they out-grow the tank, I will move them). I also have a variety of corals -- Florida Ricordea, Acan Lord, Bicolor Hammer, Plate Coral, Psammarcora, Leaf Plate Montipora, Red Goniopora, Torch Coral, Pagoda Cup Coral, Montipora Digitata, Harry Mushroom, and a couple of Gorgonia.
Any ideas?
<Perhaps this Mandarin is "getting stung" by some of your Cnidarians... But overall/in finality, I would not be concerned re this color change/movement>
Jim Rosenblum
<Bob Fenner>

Life Span - Mandarin    9/18/13
Thanks Crew for your guidance and support over the years. A simple question today...
I've had my female Synchiropus splendidus for 7 years (the first male lasted 5). How long will they live in captivity?
<Mmm, at least ten years... Have read (though anecdotal) accounts of Europeans claiming they had them for 12-15 plus. Bob Fenner> 

Goby mating and behavior question... -- 10/07/11
Hello, Thank you for having such a great site available to the general public.
I've searched your site for the information needed but did not find it.
We have a male and female green target Goby's.
<Mmm, the callionymid, Synchiropus picturatus I take it>

The male has been in the tank for at least a year with a cleaner shrimp which past several months ago.
So, we thought we'd get him a girlfriend.
<Mmm, don't live as pairs in the wild... Males go courting about sunset... temporarily drawing out females in Acroporid et al. branching stony corals... "jousting" w/ other males for reproduction...>
We got a female green target Goby. We acclimated her to the tank (floating her in a bag in the tank, adding tank water to the bag).
They were very curious about each other at first and hung out a lot together.
After about a couple of weeks, she's been nipping at him, which is a little surprising, since she is a little more than half his size.
He is not aggressive with her at all.
<Mmm, how big is this system?>
It seems that we're missing something, for sometimes they hang out just fine with each other and at other times she is aggressive, nipping and chasing him.
Is there some sort of Goby Language thing we're not getting?
<Likely goby knowledge... I'd be separating these two... or adding more "natural" decor for habitat, hiding... getting out of visual range...>
<Welcome. Bob Fenner>
PS - If these two were to ever mate, would we have to split them up when babies are born? Or, do they eat their young?
<Oh! Please read here: http://wetwebmedia.com/mandreprofaqs.htm

Scooter Blenny acting strange  1/28/11
Hi there,
90 gallon FOWLR
Sal. 1.022
<Low... I'd raise...>
Ph, 8.2
Nitrate 20 ppm its high I will change water today.
Nitrite 0ppm
Ammonia 0ppm
Alk high to 2.8
<? In what units?>
First time nitrate and Alk are high I wonder why?,
<See WWM re>
anyway I will change water today. All the fish are fine as to swimming and eating but one.
I have a scooter blenny, I have had him for 9 months now, and he was always very active, swimming around.
<These fish do vacillate between periods of high activity and lethargy>
I got new fish about 1 week ago, 1 lawnmower, blue tang, bicolor blenny and a urchin.
<The Salarias or Ecsenius could be harassing the Scooter>
Now since 2 days ago, he isn't active, he was barely breathing in a corner, now today he was a bit hidden inside some rocks, still not active, I haven't seen him eat, and I see he's breathing very fast, I put some food close to him (he doesn't move when I get my hand close to him, but he is alive), and it look as if he was sneezing into the food or blowing it away.
I changed the water 2 days ago when I first saw his behavior but I see that it didn't help, so I'm doing it again today because of the water parameters.
I attach a picture of him, but its very blurry cant do better then that, and you can only see the back of him.
Help pls, I can't even take him out to another tank.
Ingrid Leija
<Then hopefully the water change will help. Otherwise, I'd be returning this fish to the dealer. Bob Fenner>

Mandarin Fish swimming strangely  10/22/09
Hi Guys,
I checked through your information on Mandarin Fish and could not find anything on my particular situation. I bought a Mandarin yesterday from my LFS. I did not notice anything wrong with it when I bought
it. When I got home I acclimatised by dripping for half an hour. When I put it into the aquarium I noticed that it seemed like its back was bent almost in a S shape. It swims forward but its back half does not move and stays pointed to one side. Since I put it in it has been swimming and pecking  but its back half does not seem to move? What could the problem be and do you think that it will get better?
Thanks for the help
<Mmm, well... the "swimming mode" of these fishes is to "wiggle" their pectoral fins, rather than throw their bodies length-wise into sinusoidal curves... So... though the body may appear permanently "bent" to one side, this fish could be just natural, maybe try You Tube for a video, look...
Bob Fenner>
Re: Mandarin Fish swimming strangely... reading   10/22/09

Thanks for the quick response Bob!
Unfortunately when I got home the fish was already dead. I also noticed that its stomach was sunken in. I am wondering if the bent body was because of malnutrition as it did not look normal at all. I had a look at some you tube videos and none looked like what I was seeing with my fish.
<... Please... read.... Most Mandarins are lost to mis-placing, subsequent starvation... Start here:
and the linked files above. Bob Fenner>

Green Mandarin Fish  8/16/08 Lost Mandarin Hi Guys, I've had my 75G for 7 years now... will be 8 years in September. My first fish was a Mandarin Goby. Today I've noticed I can't find him anywhere... he was the star of my tank .... and my favorite fish.  I know how to care for them - I know he didn't starve to death ... Im sure the bristle star didn't get him (its too tiny) and Im sure I've no mantis shrimps. I do have a pistol shrimp but he is only 1/8th - 1/6th the size of the mandarin so I'm pretty sure it wasn't him either. So I searched and searched and I can't seem to find the answer to the simple question - What is their typical lifespan? Is it possible my beloved "Dragonboy" - that was his name - is it possible he has just passed of old age? Please let me know ... I always knew I would be upset when I lost that fish but I didn't think I would be THIS upset. I was just bragging about how I had a 7 year old mandarin goby on the forums too :-( Thanks! James P. <Hey James, Sorry for the loss. That is very impressive that you had one of these little guys live for so long. I do believe it died of old age since a pistol shrimp is not large enough to kill a mandarin. You must have had a large copepod population to keep it alive for that length of time. IanB>

Mandarin behaviour  7/15/08 Hi Are these two mating or fighting? <A little of both> The female is below and does not have an antenna in the top of the back. Along with large fins on the top of his back the male also has am antenna. The one below ( which I assume is the female) does not do anything and just lies down as seen. The male above runs his mouth on her back and keeps poking her with it and moves to and fro ( sorry if I sound a bit gross here) Any idea? I have read the faq on your website Andrew nothing like this. Cheers Ranjith <Patience... as long as there is no apparent damage... Otherwise I would separate them. Bob Fenner>

Synchiropus picturatus (green spotted Mandarin), beh.  03/19/2008 Hi How are you today? <Fine, thank you> I have had my Mandarin for around 3 months now, has done very well living off the goodness in the 4 year old live rock. I do weekly water changes, ammonia nitrite 0 nitrate 10 , ph 8.4 temp stays around 78-80. Today I noticed the Mandarin riding the current at the top of the water caused by the Filter and Skimmer, it is not fighting the current and it is very alive I dropped sinking pellets in and it dove back down to the bottom of the water. When I came back an hour or so later, it was back up at the top just riding the currents again. I cannot find anything on water currents and the GS Mandarin, do you know why it is doing this? <Mmm, in a word, "fun"> It's the only one in the tank accompanied by 2 Domino's, 3 4 stripes, 4 Yellow tail Blues,1 false clown (I think its mate became lunch for the RBTA) 4 cleaner shrimps and 1 blue emerald. No on seems to pick on it <Mmm, no... Callionymoids are distasteful... unpalatable> and water quality is good, maybe this is a normal trait and I just never noticed this before. Or is something going on here that I am missing. Anything would be great. Thanks ~Jessica <Is just enjoying itself... No worries. Bob Fenner>

Mandarin fighting   6/8/06 I have recently added my 2nd Mandarin to my well established 120 Gallon tank.  (After regular quarantine procedure.)  I believe my existing mandarin is a female, due to her small dorsal fin.  The new mandarin's dorsal fin is very long and drapes over his body.  The problem is the minute I put him in the main tank, the fight was on. <Perhaps more like a "love-tussle">   He seemed to have bit the existing mandarin and wouldn't let her go. He was holding on to her and I didn't think he was ever going to let her go.  I did finally manage to get him away from her.  Anyhow, I managed to catch him and I have now put him back into the quarantine tank.  Do you think I have two males and I haven't identified them correctly? <Perhaps, but could be dissimilar in sex>   Is this normal behaviour between male and female mandarins? <Can be, yes>   Do you think I should return the new male back to the LFS?  I don't want to risk killing either one of them. He is so beautiful!  After all this quarantine procedure I sure would like to have him in my main tank.  Any suggestions you have would greatly be appreciated. <If it were me, mine, I'd first try floating the newcomer for a week or so in a plastic colander... anchored off to a corner of the tank or so (to avoid much direct lighting/heat)... this way the two can become acquainted (mainly chemically) w/o being able to get at each other... You do have some region/s that have dense (Staghorn coral is best) hiding possibilities? I would provide this/these ahead of releasing the new male. Bob Fenner>

Mandarin Floater (Non-Eating Not The Problem Here)   4/21/06 Dear Mr. Fenner, <Laurie> I have a different sort of problem with my Mandarin dragonet. He eats fine, but today started to hang out all over the top of my tank, sort of floating. <Unusual, but happens> All of my usual suspects are within limits (No ammonia, nitrates, salinity spec grav at 23, ph a bit higher than required at 8.4 or so. 55 gallon tank full of live rock and cycled sand. He isn't being picked on, and my invertebrates are all happy and out. I'm worried. I ordered more copepods from a different site just to be safe...Is there something I am not checking for? Mrs. Smith <Mmm, if this animal is still moving about, eating, I would not "do" anything overt here... Perhaps "just a phase" or seeing/reacting to its reflection. Bob Fenner>

Jumping Mandarin  - 04/20/2006 Hi,  <Hello> Sad morning for me today as I woke up to find my mandarin fish dry on the floor. Some people I know hinted that I was a bit laughable for taking such events so dramatic, but I can't help it. I never thought that would happen. The mandarin would be the last fish to jump I thought. I should have listened better to Bob Fenner (as I usually do) when he told me that although some fish species are notorious jumpers... "Any fish can jump out". Indeed. My system is a 90 gal+30 gal fuge, 150lbs Fiji LR, 5" sugar fine DSB. Very peaceful set-up (he was not stressed or shy at all) and I did wait 6 months before adding the mandarin. He was in my tank since 6 months and still fat. Is it very unusual for a mandarin to jump? <Unusual, yes, but can be triggered by sudden bright lighting, even electrical storms at night when the lighting is off.  Being chased by a predator will often cause this but in your case you state you have a peaceful tank.> I do like the look of my open-top. I temporarily ruined my budget by getting a Giesseman 230 plus recently. It looks fantastic and the last thing I want now is to ruin the look by adding a huge sheet of eggcrate over the top. On the other side I don't want to lose a fish again or endure the stress/paranoia of always thinking a fish may jump and die any moment. Arrgh... I have been looking to find clear eggcrate but it seems it doesn't exist. I don't know if a net would look good. Probably difficult to find one made of clear nylon and to keep from bending. I tried doing one by building a frame with Plexiglas and drill the frame each 1/2" to insert the thinnest fish line but it didn't work and I gave up. Maybe use some large clear fish net and fix it in a frame used for window screens. Can you give me an advice/point out a product (manufactured for the hobby or DIY) that I could use to cover my tank and that would be as close to invisible as possible? <Might try a ¼' sheet of acrylic with 3/8' holes drilled at 3' centers for air/gas exchange.   It would be unlikely if a fish were to jump that it would hit the hole dead center.> Thanks as always! <You're welcome.  James (Salty Dog)> Dominique

Mandarin Hiding...and likely starving - 3/14/2006 We have a well established 44 gallon tank with a Mandarin(2.5 in), 2 clowns (1in) a Lawnmower (2 in) and a Long Horn Cow Fish (2 in, and yes we will be moving him to our new 162 gallon tank as soon as it is finished cycling). <<Your tank is far too small to house the Mandarin or the Lawnmower Blenny.  Both need larger systems to survive long-term.  In the case of the Mandarin, a large fishless refugium is also needed.  These guys eat an unearthly amount of 'pods.>> The mandarin eats frozen food as well as copepods and has been a very steady, healthy tank mate for 8 months. <<Frozen foods are not his proper diet.>> We did a water change, rearranged the rocks a little and removed a banded goby about a month ago.  Since then the Mandarin has been spending the majority of his time hiding under the coral, which he was never inclined to do in the past.  We have rearranged both tank mates and the rocks in the past without him reacting, so this is very confusing.  All chemicals look good, Ammonia 0, Nitrite 0, Nitrate 30, PH 8.2.  Any ideas why the sudden change of behavior? <<My guess in nutritional deficiency.>> Is this something we need to be concerned about? <<Yes.  Unfortunately most Mandarins meet a very untimely death in small tanks.>> Thanks.  Lisa M.   <<Glad to help. Lisa B.>> This is a very old question that we sent in, it was already answered. <<Very odd, as your message showed up in our inbox the day I replied.>> We moved the lawnmower and the cowfish to our larger tank almost six months ago. <<Good to hear.  I'm sure they are happy.>> The mandarin was not starving, in fact he continued to get fatter. We are well aware that they should eat pods, and he did even then, but we were thankful that he also would eat frozen foods and flakes. <<I'm sure you are also well aware, then, that these foods are nutritionally unfit to sustain a Mandarin through its full life-span.  I do wonder why you refer to him in the past-tense.>> This e-mail is very nearly a year late. Lisa <<Any message in the inbox will be replied to. I wonder what happened here...Lisa B.>>

Scooter Blenny - 03/05/06 Thank you for a wonderfully informative website! I have visited dozens of times over the last year. <<Glad you enjoy it.>> Quick question: I may have missed the answer when I searched the FAQ's, but as it relates to Scooter Blenny eating behavior, if my Scooter is pecking at the sand constantly, can I assume he is actually eating, or is this a foraging method that is just a behavioral response, and not necessarily picking up pods?  (I can't see any that's why I'm asking) <<A bit of both...is foraging/feeding behavior, but whether there is anything to actually "eat" depends on your system and the abundance of micro-crustaceans, shelled protozoa, etc., available to the dragonet.>> I've had my 40 gal tank up for over a year, and only have the Scooter and a pair of small clownfish. <<Understood, but this fish is an obligate feeder on the micro-fauna in your tank and can quickly decimate populations.>> Scooter is very small, and although the LFS said he would eat algae <<?>>, after I brought him home I read that he was a carnivore, so since my system was still establishing (I have the tank about 25% full w/live rock and I have lots of macro-algae plants not in refugium but actually growing in tank and some pulsing Xenia and mushroom coral and some snails/crabs...everyone/everything is doing well, no casualties except a featherduster that I think perhaps was in bad shape when I got him, since he perished rather quickly despite rotifer liquid sups). <<Whew...I'm out of breath after reading that last sentence <grin>.>> Anyway, I supplemented my Scooter with frozen brine shrimp in a net bag sunk to bottom, he likes that, but I'm curious if I can wean him to just eating the live stuff in the tank. <<It's not likely you have a large enough tank/enough rock for this.  If the fish will eat frozen foods, try to feed it some frozen Mysis shrimp and frozen glass worms.  The brine shrimp is really very lacking in nutritional quality.>> I see evidence of small white cylindrical growths on the side of my tank...tiny, about size of dull pencil tip.  What are these, do they provide food? <<Tiny Serpulid worms.>> Never saw him peck at them, always pecking at the sand.  His stomach, while not emaciated, is not plump either....so I can keep supplementing him, but again, is he actually getting food when he takes a mouthful of sand?   <<Probably not always.>> MANY THANKS!   Sue <<Regards, EricR>> PS I will be launching a 150 gallon tank this Spring. I am so excited I'm almost obsessed!   <<Heee!  Is always exciting to go bigger!  EricR>>

Mandarinfish behavior, systems... - 2/28/2006 Bob, <Bill> I've been in the hobby on and off for about 35 years and just set up my first 'reef' tank a little over a year ago. (180 gal.) With the exception of a couple of minor problems everything is flourishing partly due to the use of your Conscientious Aquarist  book. <Glad it has been of use to you> I have a question regarding my Mandarinfish. I've researched it extensively and can't seem to come up with an answer. This fish quite often emits a milky colored substance from its gill area. <Yes... "mucus"... Callionymids are quite slimy...> Before being able to ascertain the area it was coming from I thought it my be 'wishful thinking' on its part thinking that it was spawning, but it is coming from the gill area. I was told by a not to experienced aquarist that it was a slime coat of sorts that was expelled when the fish felt threatened or stressed. Is this correct If not, please explain. Thank you, Bill Bush <As far as I know this is so... and not a big deal in a system of your size, likely make-up and maintenance due to dilution. Apparently their mucus unpalatability is their principal defense against predation... Bob Fenner>  

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