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FAQs about Convict/Engineer Blenny/Eel/Gobies who aren't, Family Pholidichthyidae

Related Articles: Convict Blennies

Related FAQs: .

Who's that peering up from rocks?

Pholidichthys leucotaenia Jumpers?    1/9/14
Greetings!
<Salud Joe>
Thanks so much for Wet Web Media as well as all of the great publications!
I have all of the Fenner, Calfo, Calfo & Fenner books and they are all quite worn (my Conscientious Aquarist is a sad site indeed). Still waiting eagerly on Volume 2 of the reef series but have heard that as of now it's a no go.
<On its way someday>
Just wanted to check my fish stocking list with you if you have a brief minute. Tank is a 6 foot 155 gallon in-wall reef set up that was established in August with 55 gallon sump with 5" DSB refugium as well as a mud refugium built in. Mostly going well so far minus the usual kinks involved with a set-up like this.
For fish stocking, I have only 3 so far from the previous tank: Small Midas Blenny, tank-bred adult Clarkii Clown, and small Royal Gramma. Have seen quite vicious versions of all of these fishes but these (for now) are all quite docile.
In addition to these, how does this stocking list look?
5-7 Chromis (have not decided on species)
Powder Brown Tang (japonicus sp.)
Pacific Blue Tang
Watchman Goby
Leopard Wrasse
2 Convict Blennies
Variety of Cleaner Shrimp
<Mighty fine; though I might add another Convict... more interesting, secure in groups>
Would very much like to add a few Heniochus diphreutes but have been searching for years without luck. I've probably seen them in the LFS but neither I nor the folks there are able to discern the difference between them and H. acuminatus
<Common problem in both ID and relative availability>
The main issue that I'm concerned with is the Convict Blennies. I cemented all rock work with the Marco Rocks cement product, followed by adding the aragonite. I don't think that burrowing will effect the rock structure, although I only added about 3/4" of sand as to keep it in an aerobic state.

<Okay>
I currently have 3 lids, each with a 10" x 6" square cut out in the middle.
These were cut for improved light penetration as well as enhancing the shimmer of the Kessil LED's. I noticed that when water gathered on the bottom of the lid, the shimmer effect was eliminated.
Is there a chance that, pardon the pun, the convicts will escape from these opening? Wasn't sure if their similarity to eels carried on into this aspect. I'm fairly certain the openings will not be an issue for the remaining live stock.
Thank you so much!!
Joe
<There is some possibility... but a system this size, the amount of tunnel-cover, I think you won't have jumping issues. Bob Fenner>

Injured goby... no info.     7/5/13
Hi Crew. I have an Engineer Goby that is 10-11 years old.  About 4 months ago we noticed that his color had become very dusky and dull and his behavior was a little off.  He frequently came out into the open for extended periods of time, which was very unlike him, and he started eating less.  I have been able to find very little information about the life
expectancy of the engineer gobies,
<Have been known to exceed twenty years>
 nor have I been able to find much about changes that come with aging.   We watched him carefully and about a month ago his color improved and his behavior moved back toward normal.  Last week, however, he started having difficulty controlling himself when swimming in 'open water' and he has been laying along the front of the base rocks to keep himself from floating away.  He spent 7/2, 7/3 and 7/4 under a base rock (which is normal behavior for him), and this morning was out in the front open area of the tank.  He has an open and raw area on the top of his back that is about an inch long.
<And the caudal/tail is damaged, chewed possibly>

 I don't see the other fish bothering him,
<... what are these other fishes, what re water quality tests, gear/set up, foods feeding...>

 so I can only assume that it is related to staying under/laying along the rocks with increased frequency.  He is laying on the sand in the corner of the tank with the back half of his body floating upward.  (Photo attached - looks like his eye is gone, but it's just a bad picture!) Planning to get the quarantine tank up and running and try to get him moved today, but I'm wondering if you have any other thoughts, information or suggestions. 
Many thanks! Susan
<You should provide data; have you read on WWM re Pholidichthys? Bob Fenner>

Engineer Gobies - how many is too many?     5/21/13
HI Bob (or crew), hope you're well! My 200G 5' FOWLR tank currently has 2 very large Volitans lions, a harlequin tusk, a red Coris wrasse, and a large (12") engineer goby. I see that a teacher in a nearby school is looking to place 6 small engineer gobies, to shut down her small saltwater tank.
These fish are now about 4". I've thought I might take these in and grow them to size in my 30G (currently empty) aquarium, then transfer to my larger tank.
<Sounds good>
Would you attempt this?
<Yes I would>
Is this too much of an engineer crowd for a 200G to sustain?
<Mmm, no... the adults are secretive as you know... live communally... I think it would be many years before they were too much>
The current goby seems to have cleaned out all sand from the existing rockwork, and seems happy to be a loner, but I've wanted to increase the tank's headcount anyway...
<The solitary animal will be glad of the company. Bob Fenner>
Re: Engineer Gobies - how many is too many?     6/1/13

Hi Bob...per prior email...update on the Engineers...
I rehomed all 6 into the 30G as planned. previously they were placed in pairs in separate 10G tanks. Now I see that 3 of the six, particularly the larger ones, have significant battle wounds. Shredded fins and blotches.
<Patience; move them>
There are several possibilities here. I have not observed any communal raucous whatsoever, although a) I haven't watched all hours of day and night and b) yes, as expected, they do spend more time hidden than out and about. There could be one renegade (or perhaps more infighting). They have mostly taken up residence within a large piece of live rock. I also have 3 peppermint shrimp in the tank, and there may be an unknown live rock hitchhiker causing the carnage as well.
<Likely bickering amongst themselves. This will abate on its own>
I have watched them go from bad to worse. I have considered that I would move the peppermints and one or two of the largest ~6" gobies (and therefore the worse beat up) into my display. There will be perils there as well - the 12" engineer (who could finish them quick if it doesn't want neighbors), the volitans (probably won't get to them, so long as I distract them when I place the engineers).
<Mmm>
Or maybe I should add them all to the display?
<Yes I would>
 Is it possible the large engineer would more readily "adopt" a brood of youngsters? Seems I have increased risk of losing some to lions in this regard? Any thought on a plan?
<The Lions will likely recognize them as venomous, unpalatable. Have only "seen" one incident to the contrary. The larger will likely ignore them.
Bob Fenner would move all at once>
LR Hitchhikers in QT - OK to transfer to FOWLR display? and engineer gobys     6/1/13

Bob,
<Big D>
Based on my emailing with the Engineers, I've decided to transfer all life from my smaller tank to my display tank. Why not combine households...
<Mmm, well, the Lions may well inhale the shrimp>
There are a few hitchhikers I wonder if I should have worries about with this move. They are the stinging celled specimens in the pictures (which I am having difficulty getting a positive ID for, based on WWM and Google pictures), and also a hairy gorilla crab.
<... the polyps... some sort of stony coral... May be a single Caryophylliid. See WWM re>
They will move, with the engineer gobies and peppermint shrimp (aka lunch),
to my FOWLR display which has - 2 large volitans lions, a large harlequin tusk, a medium red Coris wrasse. A Rabbitfish and trigger will be added later.
<The Labrids will definitely consume the shrimp>
Should I worry that these hitchhikers will threaten my fish or otherwise become nuisances?
<Mmm, no. BobF>
Thanks for your opinion, Dave

Ask the crew a question    10/8/12
Hi, can you please help me to identify this Marine fish?? It is about 10 inches long and about 3/8 inch thick. Sorry about the picture quality
<Mmm, is this a viviparous blenny? An eelpout? Where did you, or other collect this fish? Bob Fenner> 

 

Re: Ask the crew a question, Not Blenny ID      10/9/12
I don't think it is a Viviparous Blenny. I bought it in Australia
<Mmm, there are eelpouts/Zoarcids in Australia though... perhaps a blennioid>
 and they called it a Reef Eel, which it obviously is not.
<Correct; not an anguilliform; has rayed fins>
 The closest fish that resembles mine (that I can find) is a Pholidichthys leucotaenia but I thought they all had markings and mine doesn't. Have you ever seen a Pholidichthys that doesn't have markings??
<Never... this monotypic genus, family always has appeared the same to me... Whoops! Just looked on Fishbase.org and there IS a second species:
http://www.fishbase.org/summary/Pholidichthys-anguis.html
Does appear similar, IS found in N. Australian waters... is this your fish?
Bob Fenner>
Re: Ask the crew a question, not blenny ID      10/10/12

I did see that species when I was doing the research on the leucotaenia, originally I thought it probably wasn't my fish, but am now starting to think it might be. Why do you think they have no pictures of this species and/ or a common name for it?
<Unlike its congener it's quite rare... I've never seen it>
 Also they don't mention what colour it should be.
<You may have to "run down" the original description/paper... linked on Fishbase...>
 Do I have one of the worlds newest and rarest species of Aquarium safe fish?
<Could be>
Or it more likely Australians are too lazy to finish their work?
<Mmm, unlikely... Cheers, Bob Fenner>

Engineer Goby tailing my clown fish 5/12/2011
Hi
<Mona>
I have a Red Sea Max 250 (60g.) saltwater tank. I have live rock, some corals, 1 six line wrasse, 2 clown fish, 2 engineer gobies,
<Pholodichthys? Get much too large for this setting>
2 spotted cardinal fish and 1 royal gramma. I also have some snails, a tuxedo urchin and some crabs and hermit crabs.
<What species are these crustaceans? See WWM re their compatibility>
My tank is about 3 months old.
I had bought the ocellaris clown fish as my first fish. They were a wonderful couple and got along well. Even though they were both the same size. Then due to a dead slug (or so I believe), one of them died. I bought a replacement partner and my 7 year old insisted on a black ocellaris. At the pet store, I saw engineer gobies and fell in love.
<A really neat species; a fave of mine... but grow to more than 18 inches...>
I know that my tank is smaller than their requirements, but they are still small and maybe I can upgrade when needed. Honestly, I just didn't know they needed a larger tank when I bought them.
One of the engineer gobies is hiding just like the description of the fish states. I actually barely ever see it, except when I catch a glimpse of it under the rocks in one of the many caves I created. The other one is acting oblivious to the fact 1. that it should be borrowing, it is swimming like a regular fish 2. that there is another engineer goby in the tank 3. and it seems to think it is a clownfish, because it is tailing the clown fishes all the time!!!! Is this normal behavior? I keep thinking that it has mistaken the black Ocellaris for another goby???
<Interesting speculation>
The clown fish both seem to be a bit annoyed by their stalker. What should I do?
<Like most adolescent behaviors of humans, indulge this fish for now... will likely "grow out of it" in time (months)>
Thank you very much in advance.
Mona
<Welcome! Bob Fenner>
Re: Crew@wetwebmedia.com, Plotosid, nee Pholodichthyid?  5/12/2011
Hello,
<Mona... a fave island (Monkey)...>
I am sorry for writing to you before you even responded to the first email, but I have been looking every where for a good reason why my engineer goby is tailing the clown fish. I think I might have found the reason. Is it possible that this engineer goby is not really an engineer goby and is a Plotosid catfish?
<Mmm, still odd to "tail" other fishes, but yes, would be much more "out and about">
I read in one of the FAQ about the catfish that it might hit the other fish with its head while giving them a small dosage of the venom.
<Rare>
I looked closely on the pictures online and the difference I see is that this fish really has a catfish-mouth!
<Ahh>
I have meanwhile put it in a floating separate tank in the tank and I plan to take it back to the fish store and give them a piece of my mind for selling me the wrong item (I carry much of the blame, because I did not notice the mouth earlier).
<Are very similar in appearance...>
The poor clown fish have endured enough pain!
They seem much happier since I isolated the fish.
Let me know if you think I am on the right track of thinking before I subject the fish to any more stress than I already have! (Bagging it and driving it to the store. I hope it survives the night in this confined space).
<Do take care not to get poked by the spiny portion of the pectoral fins>
Thanks again
Mona
<Again, welcome. BobF>
Re: Crew@wetwebmedia.com. Eng. Goby, Cat?    5/12/11

turns out I got a catfish!
<Oh!>
Pet store apologized as soon as they saw it and replaced it with engineer goby.
Thanks
Mona
<Thank you for this follow-up Mona! BobF>

Engineer Goby on the Prowl -- 02/02/11
Hello Crew!
<Hey Sus>
I am in need of emergency advise! I have a 180 gallon live rock with fish marine system. My livestock includes:
Keyhole Angel - in the system for 6 years
Yellow Tail Damsel - in the system for 6 years
Pink Skunk Clown - in the system for 6 years
Pajama Cardinal - in the system for 4 years
Yellow Tang - in the system about 3 years
Eye Stripe Tang - in the system about 5 years
Sailfin Tang - in the system about 4 years
3 Engineer Gobies - oldest has been in the system >10 years, the other two for about 4 years (they were introduced to the system at the same time).
<Neat animals... I imagine your are quite large by now>
We generally have no aggression problems within the system. We had 4 Gobies until about a year ago. Three of them hung together and one always hung by himself under a rock in the corner of the tank. Out of the blue one morning, one of the threesome was all beat up and the old Goby was relentlessly aggressive to the point that we had to move the injured fish to quarantine. He did not make it. At that time we thought that perhaps he was sick and the others were chasing him away because of the illness.
<Mmm, yes... this is an interesting species behavior-wise... see the Net, perhaps there is some video of how they and their young make their lives>
The little Goby that hangs by himself has always been a little skittish, almost afraid of his shadow to the point that he pokes his head out from under the rock far enough to grab a little food and that's all we see of him.
<Really needs to be in a separate system>
Yesterday he spent hours swimming around the front of the tank. We finally saw the big/old Goby charging at him as he swam by, and we also saw him chase him out from under the rock that has been his home for the last few years. Last time we checked on him last night, there was no sign of any serious physical altercation.
Today, the old Goby was still harassing the little Goby a little bit, but he was REALLY going after the Sailfin Tang. The Sailfin usually swims openly and freely around the tank with the other two tangs, but spent most of the day 'cowering' behind the rock. No matter where he went, the old Goby was almost as relentless as he had been yesterday toward the other Goby. I did not see anyone actually doing it today, but at some point since yesterday, someone made quite a meal of the sailfin's fins. They are all chewed up.
<Time for a much larger tank...>
(About 6 months ago, we lost two Pajama Cardinals. One died in the main tank before we could get him into quarantine, and the other died in the acclimation bucket on his way to the quarantine tank. They had the same problems with fin chewing...these also more or less appeared overnight. We assumed that the other Pajama Cardinal was responsible, but now I am not so sure...)
<Could be>
So I guess I have a few questions about this. Why in the world would fish that have been living together for so long suddenly turn on each other?
<Growth, change...>
Is it normal for an Engineer Goby to attach a Tang?
<Attack? Not really, but as stated... Pholodichthys gets quite large, and can/does become territorial...>
Other than removing the aggressive fish, any suggestions?
<The bigger world>
(Because of the way they get under the base rocks, removing a healthy Goby from the main tank in a process of about 8 hours total. It requires removal of almost all of my live rock, and then restacking it all back into the tank...)
Thanks for any thoughts you might have!
Susan
<Welcome. Bob Fenner>

Engineer Goby, sys.   1/23/11
I am breaking down my 115 gallon tank and am thinking of keeping my engineer goby. Would it be okay in a 44 gallon tank?
<If fed... likely so>
It currently resides under a rock pile that measures about 18 x 21 inches.
The engineer goby I'm guessing is about 10 inches long, I've never seen it all the way out of it's rock pile. I've been trying to find a home for it, but reefkeepeers don't seem to want it because of fear of digging and I really would like to keep it.
Thanks,
Melaine
<Would/will be a nice companion/pet. Bob Fenner>

Moray identification... Pholodichthys   12/27/10
Hi:
<Howsit?>
Have a look and help me please. This guy (gal?) is new and reportedly from the "western Pacific".
<Mmm, is>
Bar count is lower than for E. polyzona, but none of the online images for G. rueppellii match even closely.
<Nope>
What you can't see in the photo are well defined very fine dorsal spines that yield a serrated edge along its entire length. I've got to start a diet soon and assume from the rounded snout its a crustacean eater. Any
help is appreciated.
JZ
<See here: http://wetwebmedia.com/pholodichthyidae.htm
Bob Fenner>

Re: Moray identification  12/28/10
Wow
<Heeee~!>
LFS gave this to wife as an 'eel" for a small specimen tank the day after x-mas.
<Mmm, well, not a true eel, nor goby or blenny for that matter...>
My 11 year old son said "hey...I think its one of those snake gobies we had a long time ago" (he meant at least five years ago!).
<Dang!>
I said that I would look for some juvenile photos of potential morays. Looks like I have a budding ichthyologist.
<Do get him interested in finance, accounting, marketing... at least as a double major!>
We'll go back to see if they have a few more of these "eels" and we'll move them all to the large reef display.
<Good... is a VERY social species as you've read>
Maybe they can order a juvenile moray for us as this is what he really wanted.
<Ahh!>
Thanks for the timely help.
JZ
<Certainly welcome. BobF>

Engineering Gobies fighting, sys., stkg.    6/13/10
Hi guys,
<Howdy Harry>
First up, your site looks like a brilliant online resource. I think be needing all the help I can to get me started.
My wife and I were recently given a 54 litre tank, (our first), in which we have housed an engineering goby for the past month.
<Yikes... this fish... gets waaaay too large for such a small volume>
He was recommended to us as a good first fish to own, being hardy, tolerant of other fish and very interesting to watch.
<I do concur>
So far things have been great, he was very shy at first, but has laid claim to several of the rocks in the tank, making a burrow under each, and will dart around the tank at feeding times.
Yesterday I introduced a second engineering goby to the tank, as much of the online content I have read seemed to indicate that they were social creatures.
<Mmmm, IF from the same brood, OR kept in a large (enough) system, in a shoal>
At first, the newcomer went straight into the burrow alongside our existing one, but was driven out. Shortly after, it made its own nest under a new rock I'd purchased at the same time, on the opposite side of the tank, and they let each other be.
This evening, however, our original goby has been dashing from rock to rock, evicting our newcomer from wherever it takes shelter. He also seems to be getting more and more aggressive towards him.
Is there anything I can do to encourage less territorial behaviour in our original goby, such as providing more shelter, more food, rearranging the layout in the tank etc, or will they need to be separated permanently for the safety of the new guy?
I appreciate your help on this one
Harry
<Really... you need a much larger tank, a few more individuals... Please read here: http://wetwebmedia.com/pholodichthyidae.htm
and the linked FAQs file above. Bob Fenner>

Hector's Gobies and Engineer Gobies 3/8/2010
Hey gang! Long time reader, first time writer. Most of the time I can find what I'm looking for. Currently, I have an Engineer Goby
<Mmm, a very social species>
who's just now getting his vertical stripes, although in all honesty I was quite fond of the horizontal ones myself.
<Hee heee!>
This weekend a fish caught my eye and immediately fell in love. When I asked what it was, I was told he was a Hector's Goby. Boy did my heart sink. I told the guy I had an Engineer Goby and a first he was leery, but he said they could probably live together in a 55+ gallon tank, which mine is just that, 55. I was under the impression that you should not have two gobies co-existing,
<Mmm, well... the Engineer... is not really a goby or blenny...>
although from the forums I've read, many people do.
<Oh yes>
So my question is, what is your thoughts? Can these two co-exist since they are both very peaceful and Bob, my Engineer Goby, only comes out during feeding or extreme boredom?
<Likely will be fine if there is not too much disparity in their sizes... i.e. the Pholidichthys can't fit the Amblygobius in its mouth. Do note the former does/will get much larger in time. Please read here re:
http://wetwebmedia.com/pholodichthyidae.htm>
Digging out his rock repeatedly, knocking it over and starting again is about all he cares about except for feeding time!! :) I've tried search engines, and a few web sites, but I can find nothing that talks about these two specifically. I hope I'm no bother, but I'd just love to go back and get him if at all possible. Thanks so much for your time!!
Jess
<Thank you for your query. Bob Fenner>

Engineer Goby comp. w/ Clown Tang, Maroon Clown or Blue Jaw Trigger... 2/4/10
Hello everyone at WWM.
<Hi>
I recently acquired a engineer goby from a friend breaking down his tank.
He had him for two plus years in a community tank. After a week in quarantine I added him to my doing he was eating good and showed no signs of disease.
First night in my tank I woke up to my Clown Tang torn to pieces barely alive. I quickly transferred him to my sump I expect him to die shortly.
My first question is could the Goby be the issue or is it more likely to be the Blue Jaw Trigger, also in the tank are a Bi Color Blenny, and a Gold Striped Maroon Clown.
<Either the trigger or clown are much more likely culprits.>
Also is there anything I can do for the clown if he survives these next couple hours (i.e. Additives)?? Thank you in advance for all of your hard work and quick response Michael.
<If he is as torn up as it sounds removal to a QT tank and treatment with a broad spectrum antibiotic may be beneficial.>
<Chris>

Engineer Goby may be sick 11/11/09
Hi. I'm hoping you can help me; I can't find info on this problem anywhere, and you guys seem to have a lot of experience.
<Oh yes>
I've been keeping a 30 gal saltwater tank for about a year now, and just last month moved my 2 engineer gobies (about a year old), 2 clowns and various cleaner crews into a 50 gal. tank. They used to have a sand bed, which I changed to gravel in the new tank, there's lots of live rock that I pushed all the way down to the glass to prevent cave-ins.
<Good idea>
Tank temp is 80F; I'm a water chemist, so I do my own testing, and conditions are nearly always "perfect". I had an ICH infection in the clowns prior to moving, which I made sure was cleared for more than 2 weeks before adding them to the new tank. The engineers never got the ICH, but one of them now has what looks like a tumor under his skin, near his dorsal about 3/4 of the way down his body.
<Perhaps related to the treatment>
His stripes continue right over it; it doesn't look discolored, but there's just a large bump on his body. Could it be a parasite?
<Small possibility; likely not>
If so, how do I treat? I'd heard formalin was toxic to these guys.
<Is toxic to all life; a biocide, crosslinks proteins/AAs>
The other guy looks fine. They are both active and eating. Thanks for whatever help you can give.
-Jessica.
<I would not "medicate" this fish... With time, perhaps there will be spontaneous remission. Bob Fenner>

Re: Engineer Goby may be sick  11/11/09
Thank you for your reply! I feel better just thinking I'm not neglecting the little guys.
<Pholidichthys is one of my faves!>
Incidentally, neither was ever treated for ICH; I treated the clowns separately, because the engineers never had any symptoms,
<These fish are often the very last to fall prey to parasitic, infectious or environmental ailments>
and once the clowns cleared up, it never came back. It's great to get your advice; the guy at the fish store said he just kills his when they get sick.
<... Unacceptable>
Not helpful. Kinda disturbing. Anyway, thanks again!
-Jessica.
<Welcome! BobF>

Quarantine/Engineer Goby 6/17/09
<Hello Shelly>
I have adopted an engineering goby <Engineer Goby> from a guy tearing down his tank. The fish is large and healthy. He is living temporarily in my reef tank at home (55g), but is destined for my reef tank at work (220g). I have never put fish in my tank at work without treating them with 2 weeks of copper first, but I know this species is supposed to be intolerant of copper. The other new fish I adopted are currently living in the quarantine tank (also 55g) with copper and will go to the work tank after 2 weeks of this, then the "hospital / quarantine tank" I have can be used for the goby. The tank he is in now has had ich in the past, so I want to treat him with something to make sure he doesn't contaminate my tank at work. Should I use a formalin dip? hyposalinity?
< It's not a good idea to treat fish with copper or other medications if no signs of a parasitic disease are present. It could cause more harm to a potentially healthy fish. Is best to observe in quarantine for two to three weeks. I don't understand why you were not concerned about putting the goby in your reef tank at home. Since the goby is already in your 55 reef, I'd leave be and observe for a couple of weeks. Any disease the fish may have been carrying is now in your 55 reef, but let's hope not.
To answer your dip question, I would start with a freshwater dip before doing a formalin dip, may not be needed. See here.
http://www.wetwebmedia.com/dips_baths.htm>
Thanks,
<You're welcome. James (Salty Dog)>
Shelly

Engineer goby, color/beh.  11/20/2008 Hi my name is Misty Ketner and I have a quick question on my engineer goby. I have a 55 gallon tank and water quality is good, but my engineer goby is turning white all over his body can you tell me why? Thank you for your time Misty <Mmm, I take it we're talking about Pholidichthys leucotaenia... I have never seen or heard of this species "turning white"... as young they look to be mimics of the common tropical reef catfish, Plotosus lineatus (with horizontal bands of black and white... but at a few inches develop more intermittent blocks of dark and white... My pitch, pix here: http://wetwebmedia.com/pholodichthyidae.htm Perhaps yours was displaying a "sleep/nighttime" coloration... or is/was stressed? Bob Fenner>

Convict blenny and pistol shrimp 11/1/08 Hello, <Hello Melaine.> Yesterday I added two juvenile convict blenny's to my well established 120 gallon (saltwater) tank. They spent the night in the open and this morning had disappeared into the sand which I expected them to do. Problem is that they burrowed into the sand at the same end of the tank that my pistol shrimp has his den and tunnels. I have not heard a lot of "snapping" but was wondering if the blenny's encounter the pistol shrimp, will they be stunned and killed? <Could be, see http://www.wetwebmedia.com/alphcompf.htm.> The two juveniles are slightly bigger than the shrimp. <There is a good chance they are just hiding, getting used to a new environment at this point. But, the shrimp could be a problem.> Thanks in advance for your input, Melaine <Welcome, Scott V.>

Convict Blenny 05/30/2008 Hello Crew, Bob, <<Hello, Andrew this evening>> I have a 215gallon tank and I have been researching Pholidichthys Leucotaenia (Convict Blenny or Engineer Goby) with a view to buying a small group and I have a some questions that I can't see answers to elsewhere. <<Sounds good>> I read comment here from Chris J. Gallant about losing the Scooter Dragonet and was wondering are P.Leucotaenia known for sand sifting, thus stripping the sand of it's microlife, rather than just digging? <<They do, however, their main role is doing what they do best, engineering. They will readily eat any foods, and new foods can be introduced to the entrance of their burrow to entice them to eat>> Or do they actively hunt Copepods thus putting them in direct competition with the Scooters? I have a male and female mated pair of Scooter Dragonets already and don't want to risk them. <<I don't see this being a problem>> Also, I read that P. Leucotaenia should be kept in groups but I can't see a recommendation as to whether it will be an odd or even numbered group. <<3 is a good number to go for in your size of tank. Please do read more here http://www.wetwebmedia.com/pholodichthyidae.htm >> Could you advise please? Thanks in advance, Campbell <<Thanks for the questions, I hope this helps. Good luck. A Nixon>>

Possible parasite on my Engineer Gobies  4/28/08 Hello. I have a 210gal Reef tank, 55gal Sump, and my question is that I have 3 Engineer gobies and 2 of them have these tiny white sticklike things on them. <Mmm, any chance of a well-resolved photo?> It almost looks like they were stung by something or they ran into a cactus with tiny stickers. <Might be crustacean parasites (copepods), perhaps worms... Or elements from large/r Polychaete worms...> I have searched the web and could find nothing that looked like what is on my fish, I have also noticed that my other fish are rubbing on rocks and my sponges but none of the others seem to have anything on them. I cannot get a good picture of it but they look like cactus stickers and are smaller in diameter that human hair. They are straight (do not bend or move except for where they stick out of the fish) and are about 1/8 inch long. Thanks for your time. Jillian <... a photo or two please. Bob Fenner>

Engineer goby, sel.    4/27/08 Hi crew! I read the daily questions daily (of course!) and based on someone else's question, now we have one. Simple, really .... we have (among other fish) an Engineer Goby. We originally bought three, but only one survived. <If you have room, I would try two plus more... is a very social species> He's now about six inches long and spends most of his time in one of his many caves carved out from under the rock (we were careful when we set the tank up to make sure the rock edges sat right on the glass so his digging would not cause a landslide). <Good> He comes out to eat. Well, not actually comes out, but darts out and grabs food. <What Pholodichthys does....> So now the question: We didn't know that he (or she) was a social fish. Should we add another one or two (only available at the LFS as babies)? Will there be adjustment issues? Is our fish lonely? <Ahh! This is also a very peaceful species... I would add more definitely. Even smaller specimens will be fine> Thanks for the help! We have very few fish in our 120-gallon, so if he could have siblings, we can certainly accommodate them. Thanks. Michael and Dianne <Welcome. BobF>

Engineer Goby (Family Pholidichthyidae) Stopped Eating?   4/25/08 Hi, <Hello> I have an engineer goby <Are social animals, par excellence> (Family Pholidichthyidae) that I've had for what I believe is over 7 years. He spends almost all his time under the live rock, but has typically come to one of his cave entrances to feed eagerly on the frozen krill I've fed him almost exclusively. I hold the krill <Insufficient nutritionally> with tongs and he comes up to grab it. Sometimes I can coax him far enough out to see his entire body, which I estimate is 9" long. He's a great fish. The 65 gallon tank has 2 clowns and a large pile of live rock, a large snail and some macro algae. It pretty much takes care of itself. Lately, the goby has been less aggressive. In fact, he seems unable to eat. I will hold the krill or just leave it near his cave and he will put his mouth up against it, but he won't grab it. I have started just pushing it into his cave in hopes that he will be able to eat it. I have also tried cutting it into smaller pieces. But I haven't seen him eat in quite a while (weeks?). He's still alive, so I guess he must be eating something. But I am worried about him and wonder if I should try some other kind of food. What do you think? Thanks for your help, John <Mmm... well, could be the end of this specimens life span per the setting, nutritional history... Could be egg-bound... This species does live for much longer in good care (at least twenty years)... As stated, they don't live alone in the wild. Bob Fenner> Re: Engineer Goby (Family Pholidichthyidae) Stopped Eating? 4/25/08 Bob, Thanks for the reply. <Welcome John> Is there another food you would recommend I try? I neglected to mention that I soak the krill in Kent Zoe vitamins/mineral supplement. <Most any meaty item... I'd be my usual cheap self and try a bag of "frozen sea food" from the supermarket... Frutti Di Mar... B> John <I do think this is worth a try... sometimes P. leucotaenia do "just go off-feed"... Here's hoping yours resumes. BobF> Ok. Frozen sea food it will be. Thanks again, J <Welcome. B>

Re: Engineer Goby (Family Pholidichthyidae) Stopped Eating?   6/23/08 Bob, <John> Well, I have been putting food in the tank for the goby, but haven't seen him for a few weeks. Today, he came all the way out and is clearly dying. He is breathing very hard and looks a bit wrinkled. He is not swimming well, either. I am expecting you to say that he is on his way out, but just in case you have some treatment ideas, I thought I'd ask you for suggestions. Should I just let him fade away? <Mmm, I would not... definitely. What food have you been adding? I would try lowering temperature... keep adding/soaking food stimulants to the foods offered, live ghost shrimp, actually adding others of the same species (are VERY social animals)... Something is wrong with this animal's world... Bob Fenner> Thanks, John

Re: Engineer Goby (Family Pholidichthyidae) Stopped Eating?  6/24/08 Bob, <John> Thank you for your reply. It's good to know that my goby may recover! I have been adding frozen seafood that I got at the grocery store, per your suggestion. Squid, octopus, etc. What temp do you think it should be? <The low 80's F.> Live ghost shrimp? <Yes... aka Glass Shrimp, Palaemonetes sp...> I will have to look for those. As for adding another goby, <A few if there's room> that's going to be tough for me in the next weeks as I will be away for some time. Plus, I've never seen one of these fish since I bought him 8+ years ago. <Surprising... this is one of my fave marine aquarium fish species> As for his world, I am not sure what has changed that would cause him stress. The two percula clowns seem to be doing OK and this system has been stable for many (4-5) years. I am not saying that nothing has changed, I am just not sure what it is. I will be doing another water test today. John <Mmm, most likely a "change in life"... likely this is a female... Bob Fenner>

Engineer Goby at work, sys.  03/31/2008 Crew <<Bill>> I have a question regarding the effect of an engineer goby on my water chemistry. I have a 65G hex tank with some soft corals, fish and cleaner crew. One of the interesting inhabitants is an "engineer goby" who, since taking up residence at the base of the rock pile, has really done a lot of dredging and disrupting of my DSB. Because the hex tank has a relatively small footprint and the digging action is so prevalent, I think that he has adversely disrupted the normal cycle of a DSB. My nitrites are about 0.075, nitrates at 50mg/L, ammonia is 0.25, PH 8.0, Alk is normal, Mg is 0.04. My Remora C skimmer seems to be normal. I'm doing 10% water changes 2X/wk and have reduced feeding, but the corals seem to be withering and I have also had a persistent red/brown algae outbreak. Suggestions/Comments? <<Depending on the amount of work the Goby is carrying out, its possible. However, the algae outbreak does not seem to fit with this behaviour. Elevated nutrient levels and lack of flow can/could cause the algae issue. Continue with water changes, ensure feed is not high, maybe re-position a powerhead to provide a better flow / and or add another powerhead to increase flow. Ideally, I like to see around 25 x water circulation in a reef system.>> Bill <<Thanks for the questions, hope this helps. A Nixon>>

Identifying unique Eels; Pholidichthys - 03/23/08 Hello, I have two eels that I cannot identify and I was wondering if you could take a look at them for me. <No problem. These are adult Pholidichthys leucotaenia, aka eel gobies, convict blennies. Despite their common names they are no eels, no gobies, no blennies but form a separate family: Pholidichthyidae, which belongs to the order of perch-like fishes.> They are yellow and black with round faces. Their tail resembles a ribbon. I have them in a 50 gallon tank with several other species of marine fish like a coral beauty angel, clowns, lawnmower blenny, green brittle star, and a few other invertebrates. They don't seem to be very aggressive but they really pay attention to what's going on around them. They prefer to live up under the live rock and dig in the sand. <Sometimes called engineer gobies due to that digging.> They do most work in pairs and but they swim around separately as well. I also think one of them may be pregnant but its really hard to tell when I don't know what they are. <Well possible. They have spawned in captivity and the fry were reared.> Whatever they are I love them. Here are some pictures. I can try for better pictures if you need them. Please contact me personally at my email address if you can. I hope to hear from you soon. <Hope that's soon enough. A superb pair of fish. For more information see http://www.wetwebmedia.com/pholodichthyidae.htm. Cheers, Marco.>

Sand sifters I need your opinion on a good sand sifter. I have read some not so encouraging thing about the serpent stars I was looking at eating corals, toppling rock). So I was thinking about getting a goby. I have a 29 gallon with live sand bottom and was wondering for one if all gobies do the same job of sand sifting. I really like the look of the engineer goby, if this is not a suitable sand sifter please advise as to which is a good sifter, and will one be enough? >> A good species and one that is not too susceptible to starving in a small volume... One will do. Bob Fenner

Engineer goby Hi Bob & Co., <Steven Pro this morning.> I'm considering consolidating some of my smaller tanks into a larger "misfit" tank of critters that aren't going anywhere near my reef, such as an unidentified (small!) frogfish, an overly frisky damsel, and a large coral banded shrimp that got too rough with other inverts. Basically, this is a system for not-quite reef-safe critters that I don't want to give up. I was thinking about building an extra-deep DSB and adding some engineer gobies (P. leucotaenia). I've always wanted to keep them but was too afraid to risk a cave-in inside the reef. I do have a few questions, though: 1) You (Bob) mentioned that engineer gobies are social animals in TCMA, but could you elaborate more? Do they share tunnel systems, or do they just peacefully coexist in individual burrows? <I have always seen them sharing a tunnel system, but I have never kept more than two in a tank. I also never purchased mated pairs, just two individuals that ended up sharing with one another.> 2) Are they particularly shy? Can I reasonably expect them to spend some time in the open? <They tend to not stray too far from their homes.> 3) Any aggression problems with other fishes? I suppose I would be asking too much for them to get along with jawfish... :) <I never had any problems. If your tank is large enough, 8 or more square feet of bottom surface area, you should be ok.> Thanks for your insights! Jason <You are welcome. -Steven Pro>

Convict blenny - read the fine print.  1/16/07 Hi there, <Hi here? Hi *there*!> I recently purchased a convict blenny for my 28 gallon reef tank. <Just one? This is a social animal, enjoying the company of conspecifics.> I had done a bit of research <?> and decided that one <?> would be a nice addition to my tank, the blenny is currently living happily in my isolation tank. Is this a good fish for such a small tank? <Not in my opinion, though you may get different opinions from other crew-members. http://www.wetwebmedia.com/pholodichthyidae.htm > I currently have 2 percula clownfish, a six line wrasse, various snails/hermit crabs, and a variety of sps and soft corals. <Mmm... without system specs, I'll go out on a limb and suggest you think of a smaller species.> When I purchased him I figured that I would need to deepen my sand bed and secure some of the live rock and all would be well. However, I found some information on various reefer sites saying that this is a bad fish for smaller tanks <...> and that they can do quite a bit of damage while tunneling through the sand. I also didn't realize how large they can grow, mine is currently 2.5 - 3" long. <What did this "research" consist of? Looks good, costs little, gimme gimme? No, seriously. These creatures have no one to care for them other than us. If we don't have the information required to make a serious effort of keeping them happy, then we can't begin the task. Proper selection is a key to happy hobbyists with happy fishes.> Do you think my reef will be safe and the blenny will be happy if/when I add him? <Not in the long-term.> Also, how quickly do you think he will grow in my tank? <Depends on food variety, and other factors too numerous to list, but I wouldn't be surprised with a double in size within 6-10 months.> I'm probably going to upgrade within the next 2 years but I would rather know all the info before I introduce him to my tank. <...Or before you bring him home?> thanks, Colleen <Keep reading, and don't take me the wrong way, Colleen. I'm just trying to impress on you the need to research before buying. Imagine if we had offspring before we had any formula, diapers etc! Please write with any future Q's you have. -Graham T.>

Pholidichthys leucotaenia... health   12/13/06 Hello All: Excuse my terseness, however I am in a bit of a panic. I have the following: 225 micro-reef with several species of corals about 19 fish including clowns (perc & maroon pairs), Tangs, Gobys and the subject of my problems 5 (now 4 I'm afraid) Pholidichthys leucotaenia (convicts, engineers) <Ah, yes... one of my fave fish species> All has been well for 3 and a half years, no deaths and prolific spreading of corals. Water is as close to perfect as it can be. 40 gal changes once a week or so. Some strange aliment has stricken my convicts. They have splotches of white, deteriorating fins (severe) and clumpy masses around their faces/eyes and a weird kink in their bodies about a fifth of the way on their bodies. <...!> NO OTHER FISH HAS ANY SYMPTOMS. None. Parameters are all nil. Maroons, tangs all very likely to have ich are all fine. No new introductions in over 2 years. I am at a loss. I have been extremely fortunate, I know. Hopefully the result of diligence. But now I am lost. Has anyone heard of such a focused ailment? <Occasionally... yes> Only 5 out of 20 fish, several much more susceptible than the hardy convicts? Thanks, Walter <Do agree with you re the hardiness of this species... I do suspect that some event with organisms living near the bottom of the tank... Cnidarian/s likely, is at play here... perhaps a spawning even, consumption of reproductive products has led to the present situation. The most I would do is try to bolster the "Gobies" immune systems by soaking their foods in a vitamin/supplement prep. here... and hoping for self-cure otherwise. I don't think moving them to other conditions would be prudent. Bob Fenner>

Sand-Dwelling Gobies and Bare-Bottom Tanks - 07/24/06 Good afternoon. <<Morning now...>> I currently have an engineer goby that I have had for about 1 1/2 now in my 120 reef tank.  I have a 4" sand bed in the tank.  I am planning on an upgrade to a 180, but I plan on going Bare Bottom.  I know that the engineer goby burrows in the sand as mine always does, but is this necessary for its life. <<Ultimately, yes...will likely suffer psychologically without something in which to "engineer">> So my question is: Can an engineer goby live in a tank with no sand. <<Not recommended>> Also, I have a Watchman goby and the same question goes for him. <<As does the same reply...>> Thank you. Joe <<You're welcome Joe...EricR>>

Engineer Gobies/Blennies... actually Pholodichthyids   2/1/06      Dear Dr. Fenner, <Just Bob please, no doctorate>                 I recently ready your article "Convict Blennies, Family Pholidichthyidae," and found it quite interesting. I am currently enrolled in a 3-year science research course, and I want to research convict fish. In your article you referred to "Pholidichthys leucotaenia- the white-striped goby" published in Aquarium Digest Intl. - I have not be successful in locating this reference. Do you know how I can get this article? <Mmm, perhaps a call out, visit to a local (freshwater) tropical fish society... Some of the folks or the club there will likely have the issue... or a large college library... where the school has a bio./zoo. dept.> In addition, if you are aware of any other articles or if you know of any current research projects being conducted on these fish I would greatly appreciate your help. Thank you very much.                                                                            Madeline Marens <Mmm, you might try visiting local public aquariums. Many make use of this species for ornament and to dig about large reef systems on display. Bob Fenner>

Engineer Goby sick??? 12-05-05 Hello, <Hola> What a fantastic site you have! <Thanks> There is not enough hours in the day to read all of the valuable info you have posted. I am sure happy I came across your site. <We are glad you did too.> I have a 60gal with the following: Coral Beauty Maroon (gold stripe) Clown Yellow Head Jaw Fish Engineer Goby Chocolate Chip Star Sea Cucumber Cleaner Shrimp A few small hermits and one snail 45+lbs live rock 2 NO bulbs (one blue) Sump w/protein skimmer I just did about a 10g water change a week ago, but do not have any test levels. 4-5 days ago I noticed that my engineer Goby had what looks like a cross between a white powdery to a white fuzzy substance on 75% of his body. (Sorry, not sure how else to describe it.) <No problem, the description works for me.> He shows no signs of heavy breathing (at this time), and maybe slightly less active, but for the most part seems normal in behavior. (Came out from to rocks to eat.)<Eating is always a good sign.> Now I have a yellow eyed tang that died around the same time I started noticing this on my EG, but I only had him for about 3 weeks and I believed that he died of stress from being harassed by the clown. (I never observed this but the clown has a mean streak, and I could not see any signs of illness on the tang. The tang did show some signs of stress (?) by constantly swimming up and down the glass, but he stopped a few days before he died and was acting normal again.  <Sounds like your tang came in sick. That is why a QT tank is so important. That tang should have been in QT for 6 weeks before it reached you display.> Anyway, I read on your site that the EG is a very hardy fish and is usually one of the last to show any signs of illness. To the best of my knowledge all my other occupants are doing fine.  <Watch the EG and feed him well. Hopefully he will fight off this new infection on his own. Also, do yourself a favor and go out and buy a hospital tank. Trust me it will save you more money than it will ever cost.> Any help or suggestions will be greatly appreciated.  Thanks, Jim Phx, AZ <Happy to help. Travis>
Re: Engineer Goby sick??? 12-14-05
Hi everyone, <Hello> Thanks for replying to my original question. <No problem.> Since then I tried sending another email with a pic of my sick EG but it seems you never received. (I was concerned because he did not look like he was getting better.) He has since started to improve (less slime on the body and eye clearing up, eating great, more visible before feeding) so I have some new questions: Lets say he is shaking this off and will be okay without any quarantine etc, what about my other fish? Did they have (or built up) an immunity to this? <They most likely already had an immunity to it. All animals should be able to deal with any natural infection on their own, as long as they are healthy.> Will it (what ever it is) still be in the tank, and what should I do about it? (If anything) <It will be in the tank, just as the chicken-pox virus is around you everyday. You will never 100% clear a tank of disease. You can only keep your fish as healthy and ready to deal with infection as possible.> How long should I wait to add another "something"  to the tank. (Am I at my max occupancy already?) <That all depends on what you want to add. If you want to add a shark... then YES you are at your max capacity.> Also At this time I have a spare 10gal.,  but do not have anything else such as a heater, powerhead, light . . . What size tank do you suggest for a QT that I can use on a regular basis? I am  thinking of buying a 3-5g setup at a discount store. Would this work or should I build on the 10g I have? <I suggest a 10 gallon minimum.> Just as a side note: The local store I go to has been great with every aspect of the hobby for me. They quarantine their new stock for a period of time before placing in the display tanks. This is why I never bothered with a Q tank at home. <That is great, but you will want to investigate how they are QTing their fish and for how long. You will also want to make sure the fish are not being QT'd and then reintroduced to water from other fish. Hope that helps and good luck, Travis.> Thank you very much for any help Jim

Eel gobies Hi, I was wondering if you could possibly give me any information on the eel gobies.  I've been searching for quite some time trying to find out anything about them.  I wanted to know what they eat, are they reef safe, how aggressive they are and how large they get.  I've seen these fish a few times at the fish stores but no one seems to know anything about them, so any info is greatly appreciated.  Thanks for your time.  Sara >>Hi Sara.  Unfortunately, I'm not familiar with any goby that is suitable for a reef that is called an "eel goby".  I will give you some links in the hopes that we can better determine what fish it is you're speaking of.  Try here--> http://www.wetwebmedia.com/marine/fishes/index.htm and on Google my first "hit" was this--> http://www.amonline.net.au/fishes/fishfacts/fish/tpurpur.htm If it was this monster--> http://sunflower.bio.indiana.edu/~sholtzma/fish.html then I would have to say that I don't believe he'd be very suitable for a reef system. <See Pholidichthys... on WWM. RMF>

Convict blenny/goby Hi Bob, <Brent> It's been a long time since I last contacted you, a couple of years at least. <Still here, there> Since then I have had a reef tank up and running using Eco-system method, I have removed the TurboFlotor 1000 skimmer with much success. I have a clam, open brain, finger coral, toadstool, pulsing xenia and a bubble tip anemone, plus several types of mushrooms and algae. Inverts are as follows: 10-15 turbo snails, 10-15 red legs, Maldives starfish and a blue Linckia, boxing shrimp and a cleaner shrimp  My fish stock comprises of a chevron tang, coral beauty, pair of maroons in the host anemone, 5 green Chromis, a mandarin fish and 4 convict blenny/gobies. <Topped off for sure> The reason I am writing to pick your brain is that the convicts (which I love) have become emaciated, all other fish stock look fine. At first it appeared that it was only 1 of the fish that was affected but on closer inspection ( not easy with these fish as you will appreciate) all seem to have some sort of infection. <Maybe so> The fish are fed with an assortment of frozen foods soaked in Zoecon and Zo?marine, a dried pellet food and sea veggies (which to be honest I don't really rate that highly). <I'd make my own> I've attached a photograph to hopefully help in identifying the disease. <<Photo is SO out of focus there is naught to do, cannot post this.>> Thanks Brent. <Are you sure these Pholodichthys are just not receiving sufficient food period? For what appear to be sedentary animals they are quite "high metabolic"... You could try adding Metronidazole to their food for a few times. Please see here: http://wetwebmedia.com/metranidazole.htm. But I would first try offering more meaty foods right down near them... twice a day for a week or so> I write to you as it was your book (Conscientious Marine Aquarist) that got me into this fascinating hobby in the first place, love the website too. <Thank you my friend. Bob Fenner> 

Convict Blenny Hello Bob, I just have a quick question. How long will a Convict Blenny live in captivity? <For many years... this is one of my favorite species (Pholidichthys), so do look for them about... there are some European public aquariums that have had this species for teens of years> I know it depends on tank conditions and 100 other things, I'm just looking for an average life span. I have one that almost 3 years old and lately it has been looking raggedy. My Tank Water is good, and its tank mates are in good shape. Is it getting old or is it sick. It looks like its skin is peeling like it had a sunburn. Thanks for your help.  Tobin <Generally a very hardy species... If all your other livestock look okay, I'd bolster its nutrition by adding some other meaty foods, soaked in a vitamin prep. (e.g. Selcon). Bob Fenner> 

Convict Blenny question Is there any way to tell the difference between the male and female Convict Blenny.   <Not as far as I'm aware, and have seen breeding adults (last at the Aquarius Aquarium in Long Island)... they were a good eighteen inches long and not-discernible> Also we read on your website that they are social. We have a 100gal and just bought a Convict and wonder if he would be happier if a mate was purchased. I do not think we have room for three. <This species is definitely "happier" in groups... will be seen in almost constant association with conspecifics. I would definitely add one or more in addition.> Thanks, and we love your site. Jerry Kammer <Thank you for being part of it. Bob Fenner>

Growth Failure in Convict Blenny (4/27/04) Crew, <Steve Allen today> Thanks again for the patience that y'all have, the greatest resource for the lost out there. <It's pleasure to play a small part in it. I have learned so much here myself.>   I have an interesting issue. I purchased 6 "neon gobies" from my LFS about 3 months ago. They were about 1.5 inches in length and lots of fun to look at. After spending ~6weeks in my vert QT they were fine and into my 200gal reef they went. I figured out rather quickly that these were not neon gobies, but convict/engineer blennies/gobies (Pholidichthys leucotaenia). I discovered this from Mr. Fenner's glowing recommendation of this interesting fish. So in a vain attempt to inform my LFS of his mis-labeling, I brought in a pic from the book. No help. <Some folks are truly stubborn.> Anyway, now 5 of them are over 4 inches long and dig constantly (amazingly, and gratefully, I placed the LR on the glass before adding the substrate). <Good move.>   The issue is with the 6th one. It has not grown at all, not a mm. It is still about 1.5 inches and only hangs with the other boys about 10% of the time. A portion of his time he spends laying on the bottom, almost motionless. He recovers (?) and is back to swimming alone after a short time. At 1st I thought that I was sold a real "neon", but after looking closely he looks like a miniature of the others. He also is the only one that seems to be hunting creepy-crawlies on the LR, I saw it with my own 2 eyes! Any ideas? According to Mr. Fenner he has rarely seen one take ill, so I am curious as to your thoughts on this "Dwarf" Pholidichthys leucotaenia. Most of the time he acts just like the others, I just worry about the laying on the substrate thing. 1st time I saw it, I thought he was dead. He's lasted over 3 months including the quarantine time and he's still alive, although admittedly stunted for some reason. I appreciate any ideas you can offer, I get really attached to these guys and I've been fortunate with my charges thus far, so I'm worried... Regards, Walter <Well Walter, it's hard to say for sure here. Many factors, both genetic and environmental, can lead to stunting. It could be lacking the hormones it needs to grow any bigger. The behavior suggests that it is more likely lacking some nutrient (perhaps being out-competed by the others) or is inhibited by being "odd man out" or "the runt of the litter" so to speak. If he is not wasting away, perhaps he will be fine but small. If you could easily catch him and put him in another tank, you could find out for sure, but I suspect that's a lot of effort in your tank. As long as he appears to be free of contagion, it may be best to just leave him be.>

Convict Blennies Hello Bob Fenner, <Chris>   Bob I wrote you an e-mail back in October regarding the 3 convict   blennies that I had purchased who where growing and quiet active in   my 72 gallon aquarium.  Recently however they have started hiding   and don't even come out to eat like they use to, they simply peek   out from the bottom and wait for the crumbs to fall to the bottom. I   have noticed that one in particular has built a cave which I can see   from the bottom of the aquarium, actually under the glass, where it   remains during the day kind of curled up.  Is it possible that   these convict blennies will produce and offspring? If not, is it   normal for them after such a long period to become secluded? <Is possible that they may reproduce. Saw a breeding community at the Atlantis Aquarium on Long Island last year... big animals, maybe a foot and a half in total length. Otherwise the behavior you describe is "natural". Bob Fenner> Best regards,
Chris J. Gallant

Worm Goby (convict blenny) This is my worm goby the LFS didn't know what it was and had ? as its name and they where 3 for 6 bucks not bad price this ones at his adult stage and never comes out more that his head to snatch on passing food notice the blotchy pattern I'm not sure how long he is maybe 5 or 6 inches this is a great fish feel free to use the pic on the web site :) <Mmm, looks like Pholidichthys to me. Please see here: http://www.wetwebmedia.com/pholodichthyidae.htm Bob Fenner>

Convict Blennies Hello Bob Fenner, <Howdy Chris> I purchased 3 little convict blennies a couple of months ago thinking it would be a nice addition to our 75 gallons tank.  They now measure over 6 inches in length, have practically dug out all the possible live sand (about 3 inches deep) around and eat like its going out of style.  My little scooter dragonet died and I am thinking it was due to a lack of food on the surface of the sand which use to be abundant. <Very likely so> The question is; how much bigger will my 3 stooges get and will they cause any harm?  I am thinking of increasing my crab, snail and invertebrate population however I am getting worried that there may not be sufficient food left for them to graze on. <Can get to more than a foot in your setting... not likely to cause trouble other than food competition, undermining anything not firmly stacked above the substrate. Bob Fenner> What do you think? <Here're my pix: http://www.wetwebmedia.com/pholodichthyidae.htm Bob Fenner> Best regards, Chris J. Gallant

Eel gobies >Well I'm back to bug you again.   >>Oy!  LOL!  Alright Sara, let's see what I can do for you, eh? >I just have a few more questions to ask you.  I have just recently set up my 75g tank to move my fish into.  So my first question is if you think the 700 gallons per hour that my filters run plus whatever my skimmer does in an hour is enough for a 75g tank, or should I add some more filtration on to it?   >>Ok, so as I understand it, you have a turnover rate of just under 10x/hour, just with filters, yes?  If so, I think this is just sufficient, though I would take care not to crowd animals.   >My original plan was to run 1000 gph with two filters but I can't get them both to fit onto the tank with my skimmer there as well.  Now my next question is about my PJ cards.  The three largest cards are looking great but the smallest one always looks so beat up.  Should I expect the smallest one to always look like this or will the rest of them back off at some point in time?   >>Are the other cards doing the beating?  If so, space may not be what they need, although it won't hurt to give it a chance.  Since you've ended up with four, it may actually help to purchase one more cardinal--he'll likely be low man on the totem pole, and if you get him sufficiently large he'll also be less likely to be picked to death. >Now that I have the 75 up and running I was becoming interested in purchasing a coral beauty.  I've never attempted one of these before, i wanted to wait till I had a well established system.  So I've been looking up lots of info on these guys and was wondering if you think that they are safe enough to go into a reef tank.  I have a few different types of polyps, a lot of mushrooms, some cup corals, sun corals, a gorgonian plus two sebae anemones.   >>Eee...everything was great till we got to the anemones.  You've picked the more difficult species here, and almost all desirable anemones have dismal records of survivability in captivity.  It is told that their lifespans are on the order of centuries, yet in our tanks it's rare for them to live beyond a few years.  Also, should the anemones decide to move around, they will sting all other sessile invertebrates.  Next time you decide on anemones, pick something with a proven track record that folks are getting splits off of like the Bubble Tip Anemone.  Hopefully these ones you have won't move around very much, but do watch them for impending death as they'll crash a system quickly if you're not careful.   >>As to the question of the Coral Beauty, I kept one in my own reef tank for years, with no troubles.  It was the MANTIS SHRIMP I had trouble with (accidental introduction, no more skipping q/t for me!).  So I think you should be able to keep one.  However, there are those stories out there of them being polyp eaters/nippers, so watch him carefully. >I also wanted to know if they should be fed a marine angel type of diet or if they're better off with lots of greens. >>A variety of foods is what's necessary, offer them both, along with more meaty foods such as Mysis shrimps, finely chopped squid, clam, octopus, and shrimp.  Soak food in Selcon a few times a week, and everyone should receive good nutrition. >I know that angels can become aggressive towards other fish in the tank so do you think the beauty would be ok with my docile cards?   >>I would expect no trouble between the Centropyge and the cards.  Just remember that this will be the only Centropyge you can have in the tank.   >And now I only have one more question for you.  I've been reading that the beauty's from the Philippines aren't hardy at all but I haven't found any info on how to tell the difference between a Philippine beauty and the rest of them.  So is there any way to tell where it came from? >>It's not that Coral Beauties from the Philippines aren't hardy, it's that it is more likely than not that they've been collected with cyanide.  There are other fish from the Philippines that are routinely collected with cyanide, as well.  The best way to tell is to ask your dealer, though many don't pay attention, they just go for the cheapest fish.  I can tell you that the wholesaler I will be working for sells Philippine fish, but she has also worked VERY hard to find an exporter who deals in NET CAUGHT fish only (please don't fall for MAC--this organization has not put a viable cyanide detection test in place).  So, when the shop orders their fish, their wholesaler should already know where the fish came from.  One excellent way to tell if any fish has been exposed to cyanide (not necessarily collected) is if they eat yet waste away.  Also, if the dealer has both huge number and huge variety of Filipino fish, you can be fairly certain that the active, difficult-to-catch fishes are likely collected with cyanide.  Other than that, I know of no way to differentiate between a Philippine fish and, say, one from Tonga.  I hope this helps!  Best of luck with the bigger tank, Sara.  Marina

Gobies, blennies... Atlantic... Pholodichthys? Hi have you ever heard of an Atlantic goby or Atlantic blenny? I bought 3 of them for 1.99 each at the pet store (cheap for saltwater fish) they are long 3" like an eel they have a black stripe on it they have made a tunnel in the sand and they live under the sand got any ideas? <They sound like engineer gobies from the description but I could say for sure with out a pic.  thanks JM

Convict blenny & deep send bed Hello, <Hi Petr, Don today> I recently added deep send bed (6" of fine Southdown sand) to my 55gal reef tank w/ sump, Turboflotor 1000 skimmer, live rock (~40lbs).  I dose Kalk and Seachem's Reef buffer.   <Sounds good> I currently have a yellow tang, two convict blennies, red Linckia starfish, a few snails and hermit crabs, and some zoanthids living on my live rock.  I love the DSB for the way it looks in the tank and also for its benefits.  My only concern is that my blennies seem to enjoy digging their little homes under and around the liver rock.   And it is not just one or two holes, they are digging around almost every piece of LR in the tank.  Is this going to mess up the denitrification process in the DSB that I'm trying to foster?  If so what should I do about it?  Thanks... <Just blennies being blennies! You might try adding some rubble (empty shells, small fragments of rock, etc) and see if they don't use these to build a 'home' and settle in. Hope this helps, Don> Petr

Re: eel gobies >Thanks for looking into this for me but none of the pics that you sent to me are of the one that I've seen.   >>You're welcome, sorry the pics don't help.  Is there any way you can get a picture?  If you can get a picture, of if your LFS has a marine fish "Bible" (identification book) it would help us help you. >I have recently seen a picture of a convict blenny and it does look almost identical to the eel goby, so my next question for you is could these two fish be the same thing, just having different names? >>ABSOLUTELY!  This is the bane of aquarists round the world--local common names vs. correct taxonomical names.  And this cross-over from goby to blenny and back again is quite common as well.  Your shop may have simply misidentified the critter in question. >I also had another question about the boxer/Pom-Pom crabs.  Can you have more than one in a tank?  I had two for a very short time and then one just died for no apparent reason.  The other one I've had for about a year with no problems at all.   >>I think you've answered your own question.  I wouldn't try adding another, especially considering that you appear to have a breeding pair of Stenopus in the same system, yes?  It may very well be that they (Pom-Poms) won't tolerate each other, as well.  Take a look here--> http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/swcrabs.htm >Also could you give me any info on how the crabs breed.  Shortly after acquiring the first one she became pregnant.  I was wondering if they are like shrimps and seem to always carry eggs or if they only carry them if they've been fertilized.   >> Look here for some information--> http://www.wetwebmedia.com/marine/inverts/index.htm >>I will tell you this, many, many animals have a planktonic larval stage.  The crabs may carry eggs (unfertilized as well), they may even carry fertilized eggs, but to rear the young would take a dedicated system.  If you have filter feeders I say let the eggs and any subsequent larvae become food for the system.  I have been unable, at this point, to find specific sexing information. >I have just one last question for you.  i have very luckily gotten two coral banded shrimps to pair up, the female of the two is carrying eggs now so i was wondering how long does she carry them before releasing them?  Also do you happen to know what color the eggs are supposed to be if they're fertilized and what color the eggs are if they're not fertilized.  Thank you so much for all of your help.  Sara >>Try here--> http://www.wetwebmedia.com/marine/inverts/arthropoda/shrimp/stenopus.htm >>I know that the ovaries of female CB's are dark and easily visible, and I also know that you are indeed very fortunate to have had a couple pair up!  Don't worry too much, though, as once they've begun breeding, it's unlikely they'll want to stop anytime soon, eh?  ;)  That will allow time to gather whatever information is out there on breeding.  You may also want to visit other reefing sites, such as www.reefs.org  This is a good means of gathering information that may not yet be published.  Our own site has a Breeder's Column at http://www.wetwebfotos.com/talk <-----------------------------------------------------------> <<<OK FOLKS, anyone have anything else to add to this PLEASE DO!  My learning curve is stretched at the moment, and I can feel my brain wrinkling as I sit here!  LOL!  Marina
Re: eel gobies
thanks for looking into this for me but none of the pics that you sent to me are of the one that I've seen.  i have recently seen a picture of a convict blenny and it does look almost identical to the eel goby, so my next question for you is could these two fish be the same thing, just having different names? <Yes, likely so. Please see here: http://www.wetwebmedia.com/blennioids.htm about in the middle.> i also had another question about the boxer/ pom pom crabs.  can you have more than one in a tank? <If the system is large enough... dependent on the size of the crabs as well... and has enough physical break-up of the space... for hiding, getting away> i had two for a very short time and then one just died for no apparent reason.  the other one I've had for about a year with no problems at all.  also could you give me any info on how the crabs breed. <Please see WWM re>   shortly after acquiring the first one she became preg.  i was wondering if they are like shrimps and seem to always carry eggs or if they only carry them if they've been fertilized.  i have just one last question for you.  i have very luckily gotten two coral banded shrimps to pair up, the female of the two is carrying eggs now so i was wondering how long does she carry them before releasing them?  also do you happen to know what color the eggs are supposed to be if they're fertilized and what color the eggs are if they're not fertilized.  thank you so much for all of your help.                       Sara <Keep studying my friend. Bob Fenner>
Re: eel gobies
>well right now they're in a 40 breeder, will be moving to a 75 later on.   >>How much later on?  A 75 would give you plenty of room to give the pajama some mates to play with (mates as in friends). >i have a small Sailfin tang, orange tail damsel, lawnmower/algae blenny, PJ cardinal, and 3 convict blennies, 2 CBS, pencil urchin, long spine urchin, blue tuxedo urchin, sally lightfoot crab, 2 emerald crabs, 1 pom pom crab, around 20 blue legged hermits, 6 Astrea snails, 1 brittle starfish and a few different types of soft corals.  i run 2 filters in my system so I'm close to 700 gallons per hour plus a deluxe Prizm protein skimmer.   >>Holy cow, Batman!  That's some good water movement for a 40..LOL!  Good thing, it's what the cards like. >I'm not sure how much that one pushes in an hour. >>Other than suggesting these fishes get into the 75 sooner rather than later, it sounds pretty good to me.  Good luck with it all, Sara.  Marina

Gregarious Gobies! I am curious about the convict/engineer goby.  Does this fish live in groups in nature or is it a solitary fish.  Does it share its burrows with others of its kind? Thanks Fred. <Well, Fred- the answer is yes- and no! Many times these fishes will congregate into small groups in the aquarium, and are quite gregarious. I have seen other specimens that seem to live a more solitary existence...always seems to boil down to the individual fishes in question. I'd start out with a small group and see how the interactions work out.. Good luck! Regards, Scott F>

Engineer Goby Hi, I am a long time reader and first time 'asker'. My LFS received some fish from someone dismantling their tank. One of them, the one that I purchased, has a goby like head and a Tesselata Eel type body, black and white in color. Neither of us can I identify it and were wondering what you think it may be. <It sounds like a good description of the Engineer Goby.> It burrows into the substrate, somewhat like a Pistol Shrimp does, making huge mounds of sand around it. From afar, it has the appearance of the above mentioned eel. Any help would be appreciated. <Please take a look at the pictures here to confirm, http://www.wetwebmedia.com/pholodichthyidae.htm> Thanks, Sean <You are welcome. -Steven Pro>
Re: Engineer Goby
Well, I am in awe at your response. <Truthfully, your description was pretty good and not too many other things it could have been. Frankly, I was surprised to here your LFS could not ID an Engineer Goby that they had in their possession. They are by no means uncommon.> It appears that you are correct. It looks like an adult, about 6 inches in length. I guess they change their appearance as an adult. <Yes, they begin with the horizontal stripes and slowly change to the banding.> Thank you very much, Sean <You are welcome. -Steven Pro>

Engineer Goby Hi, I am a long time reader and first time 'asker'. My LFS received some fish from someone dismantling their tank. One of them, the one that I purchased, has a goby like head and a Tesselata Eel type body, black and white in color. Neither of us can I identify it and were wondering what you think it may be. <It sounds like a good description of the Engineer Goby.> It burrows into the substrate, somewhat like a Pistol Shrimp does, making huge mounds of sand around it. From afar, it has the appearance of the above mentioned eel. Any help would be appreciated. <Please take a look at the pictures here to confirm, http://www.wetwebmedia.com/pholodichthyidae.htm> Thanks, Sean <You are welcome. -Steven Pro>
Re: Engineer Goby
Well, I am in awe at your response. <Truthfully, your description was pretty good and not too many other things it could have been. Frankly, I was surprised to here your LFS could not ID an Engineer Goby that they had in their possession. They are by no means uncommon.> It appears that you are correct. It looks like an adult, about 6 inches in length. I guess they change their appearance as an adult. <Yes, they begin with the horizontal stripes and slowly change to the banding.> Thank you very much, Sean <You are welcome. -Steven Pro>

Engineer Gobies "Illness" We have three Engineer Gobies in our tank that have varying degrees of the same illness. They have white or gray cloudy spots spreading on their sides. The worse of the three has it clouding over the eyes. The side (pectoral?) fins have disintegrated (each of the three have different levels of deterioration) as well as the "fins" that run along the top down the back. <perhaps a combination of pathogens here> Our fish caretaker has tried two different medications over the last 3-6 months. Each time the fish appear to get better, but then start to get worse again after awhile.  <it would help to know the meds but I will guess that some dreadful gram positive antibiotic like Maracyn/Erythromycin was one of them. Too commonly dispensed and nearly useless for marine diseases. Please use a Furazolidone and Nitrofurazone mixed drug in a bare bottomed QT tank for optimal results> What ever the gobies have isn't affecting the other fish in the tank (clown fish, yellow tail damsel, shrimp, starfish, and a yellow fish (big 2", flat, with a pucker mouth) I can't remember the name of). Do you have any idea what the gobies have that isn't affecting the other fish and any possible cure for their symptoms?  <each fish and species has a different resistance... the others may never get this or it can occur in time. Please understand and employ a proper quarantine tank for all new and sick fishes> We are considering taking them out and replacing them with something else, but if we can cure them we'd rather keep them.  <"take them out" as in destroy them? That seems to be the message here as evidenced by your qualifying statement, "but if we can cure them we'd rather keep them." Hmmm.... you are making me sad here. Else you must know that dumping them on somebody else or the pet store while they are sick will likely kill them anyway> All the fish get along well and the gobies are pretty happy most of the time. It gets scary when the one goby that has the worse symptoms gets really bad and the others chase him out of the hiding place, then the clown fish will push him around (territorial maybe or trying to keep the goby going). <yes... sad to see> The medications have definitely helped the gobies show improvement, the cloudy spots go away, the eyes clear and the fins start to look healthier (at the beginning seemed to grow back some), but now it seems like they get the "problem" back faster each time.  <the meds are not the right kind or strength. They need to be dosed for at least five days and either longer or stronger if not done in a bare QT tank (the gravel/rocks temper and absorb medication efficacy in your display tank).> Out of the three there was one with the least symptoms (he was the only one who still had complete side fins, but now they are deteriorating quickly and it's so sad to watch. <they are extremely hardy fishes and can likely recover easily> The medications were (sorry I don't know the names) white oval pills we tried 4-5 different times and most recently a stinky yellow round pill that makes the water turn yellow we tried twice. <Egads... the second med was Tetracycline!!! My friend, your fishkeeper needs to learn more about fish meds. Both of those drugs were outdated in the 80s. Many bacterial immunities to them... no wonder they didn't work. Its unfortunate that the pet stores still sell them. Let me recommend to all the excellent new fish disease reference by Noga and for an older but less expensive and still relevant reference: Untergasser's Handbook of Fish Diseases (TFH)> Thank you for any help you can offer. <If you haven't considered it already... there is an excellent aquarium Society in San Diego where you can get great local advice and support from fellow aquarists: SDMAS Aquarium societies are wonderful places for great information and fellowship. Best regards, Anthony> Michelle F. Baker

Unknown Fish Hello, a few months back I discovered a fish under my live rock that I didn't purchase so I figured it found its way in the tank off the rock. I e-mailed you guys about this and you said it would be helpful if you had a picture so here is a few. The fish was only about three inches when I discovered it but now its on to about 6-8 inches and still growing. I know its not an eel because it has pectoral fins and no noticeable teeth. Thank you for your help and hopefully you recognize it. <Please see the WetWebMedia.com site re Pholodichthyids. Bob Fenner>

Injured convict blenny Dear Bob, My 100 gal FOWLR has housed five 7"-9" convict blennies (Pholidichthys leucotaenia) for the past year and a half. <Really neat animals> They've seemed quite hardy and happy constantly rearranging their homes in the 5" sand bed. Other inhabitants are: 6" Foxface rabbit, 5" hippo tang, 2" flame angel, sand-sifter bullet goby, lawnmower blenny, snails, small scarlet hermit crabs, and one tiny Aiptasia. Last night I noticed this smaller 7" convict constantly skimming the surface of the tank. All the others were tucked into their sand homes. I thought this was suspicious behavior, since sick fish often swim near the surface, I suppose for more oxygen. <A good guess... or too much carbon dioxide...> On closer inspection, I saw that his tail has been eaten. The last one inch of his tail is gray, obviously eaten, and some red open wound streaks. I isolated him in the plastic breeding cage for the night and prepared and transferred him to the hospital tank this morning. I began treatment with Melafix. What do you suppose happened?  <Maybe a fight started this... or a falling rock...> My only guess is that somehow he got a scratch on his tail and the other members of his family began picking at it like a bunch of chickens. When he makes it back to health (I'm being optimistic now, he really doesn't look very good), I will put him in the 40 gal Caulerpa tank which has one maroon clown and one pajama cardinal and one CB shrimp. <Okay> The hospital tank is ten gal, bare bottom, two coffee mugs for hiding, heater and whisper filter, water from the main tank. Melafix, 1tsp/day as per instructions. Do you have any other suggestions? Thank you, Fellow convict blenny lover, Linda <Mmm, only my well-wishes. Kia orana my friend. Bob Fenner>

Convict Blenny offered as "worm goby" Dear Bob, Offered as "worm gobies" for only $5.95. But my reading of your book enabled me to identify these as "Convict non-goby, non-blennies". I find them attractive and may add a few to the community. Your writing is clear on their hardiness. <A fabulous species for aquarium use... seemingly very intelligent, and definitely comical...> Is this a desirable fish for my very peaceful community which now contains a true Percula clown, a sleeper goby, a yellow Hawaiian tang, 3 neon gobies, and a Gramma? Also some mushroom anemones, yellow polyps, and bubble coral. I don't want a fish that bites others (as some blennies do) or eats corals and polyps. <Shouldn't eat, bother invertebrates... but are active enough to cause your sleeper problems by eating all the food... do get to about a foot in length... saw some old-timers at the Steinhart Aquarium two days back...> The refugium looks great and all the plants are doing well except the grape Caulerpa is turning gray and doesn't appear happy. Could this be too much light? I have moved it to the bottom of the tank. <Maybe... more likely an incompatibility with other algae species... but it may still rally... I'd leave it where it is> Thanks for the advice on the pH controller. That will save a couple hundred bucks for other projects and livestock. <Ah, good... we share the same addictive attitude... Bob Fenner> Howard

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