Might have a Gobi on my hands? Desert dilemma?  1/28/07
Hi Crew,
<Doug>
You probably HATE this sort of question, first because I am nearly positive the answer is somewhere in front of me, and lastly because I am going to ask about a fish I have no photo of.
<...>
I am sorry for the inconvenience.  I would research the answer, but my toddler is screaming,
<See to them... write back when you can...>
and the fish is in the bag and floating.  Here is the issue.  I was raiding my LFS's feeder tank for ghost shrimp, and was fortunately able to get a few, but since invertebrates are not legal to sell in a pet store I was forced to take all the inhabitants of the "For Charlie"  (Charlie is the resident Oscar that is too big to sell) bucket, or leave it as is.  Now in addition to some ghost shrimp and a crayfish I have what I am told is a Gobi.  Is this fish better off with Tiger Barbs/Serpae Tetras/Glowlight Tetras, or Fancy Guppies/Neons, or would it be more humane to find somebody with a hungry fish?  
<No way to tell...>
For the time being he is in a 1 gal Betta tank by himself, 78 degrees and  under gravel filter The tank has been set up for 6 mo.s and is my seed tank for snails.
Again sorry that I was not able to research this on my own.  I really tried, but I didn't even find a picture that resembled this fish, and there was just SO much information!
Doug Alley
<Not possible to give you direction Doug... as this would entail just a blind guess as to what you have... A pic next time. BobF>

FW/BW Bumblebee Goby 10/10/06
I purchased a 'freshwater' Bumblebee goby three days ago and put him in my Endler's tank, an Eclipse 12.
<No quarantine? I just lost upwards of 8 mollies in my brackish tank because of not quarantining a new addition for long enough...>
There are eight adult Endler's in there, along with many tiny fry. It's heavily planted with Cabomba on top and lots of java moss
on the bottom, along with a small piece of bog wood and a fake log. I have one tsp. of salt per gallon of water and the temperature is 75degrees.
The problem is the Bumble Bee shows no interest in eating. I had hoped he would feast on the fry but they swim right past him and he ignores them. I even witnessed a small fry bump against his snout as it swam by.! He isn't shy, as now he spends much time resting on top of the moss in the middle of the tank.
Any advice?
<This is likely not a true "freshwater"...There are two distinct species of bumblebee gobies: Brachygobius xanthozona and Brachygobius nunus, the first being able to better "tolerate" freshwater, the latter needing strictly brackish (around 1.005 SG). See here for more info.: http://www.aquarticles.com/articles/breeding/McKane_Bumblebee_Gobies.html
You will have to establish a separate brackish tank for the goby, or find a more suitable home (probably not the LFS, if they can't even correctly identify him) for him.  From what I know, Endler's livebearers can't handle brackish water; you should slowly acclimate the bumblebee, whichever species it is, to a more suitable salinity.  See also here: http://www.wetwebmedia.com/BrackishSubWebIndex/bracgobioids.htm
Thanks, Gregg.
<Hope I've helped.  Jorie>

FW/BW Mis-mixes  - 03/26/2006
First off, I just wanted to say that I love your site and you all do a great job.  I was just wondering what you thought about the mixture of fish I have in my 90 gal tank.  I currently have 2 red devils, 1 Florida gar,
<Neat fish... illegal in many States... get way big>
1 green terror, 1 tiger Oscar, a small Pleco, 1 figure eight puffer, and 1 dragon goby.
<These last two... are increasingly brackish with age, size... should they live...>
  The biggest so far is the red devil at about 7 in.
<I'll bet! Some of these are really devils!>
So far I have had the tank for about 4 months with no casualties. Everyone seems to be getting along swimmingly.  I am worried though that with this size tank there will not be enough room for all species when they reach their full potential.
<To put this mildly>
I have gotten so attached to them all I can't bare to let one go. (Unless it's for their own good.)  
<You need at least two more tanks... and a lake if you're going to try raising the lepisosteid>
I do weekly water changes, vary their diet, etc.... and treat them all with the care they deserve.  What do ya think? Thanks - Steve, MI
<A brackish tank, an easier going cichlid tank.... See WWM re these species systems, compatibility... Bob Fenner>

FW Goby ID  2/18/06
I  am trying to identify my goby, I was wondering if you could tell me what goby is more popular in the aquarium trade: a Dormitator maculatus or a Dormitator lebretonis? Are there any other species of gobies that look like these? I think my goby is either a Dormitator maculatus or a Dormitator lebretonis. He has a blue spot just behind his gill on each side and a spotted line pattern down each of his body. He is less then 2 inches in length. I have had over 400 replies on various fish forums but no certain identification. I have searched on google but no luck, I need to know what each species looks like as a juvenile. If you could send me a photo of a juvenile Dormitator maculatus or Dormitator lebretonis or any info that would be greatly appreciated. Or if you could give me a list of popular sold freshwater or brackish water gobies that would be great. Thank you for your time and I look forward to hearing from you. Eva
< Dominator maculatus is the one that is written on the most , so we can assume that this is the most common one in the aquarium trade too. Your description is consistent with the photos. -Chuck>

FAQ on Sleeper Gobies ... Butis butis ID, beh.  4/26/06
Hi,
<Hello there>
I was just browsing around your site and noticed there was someone on the sleeper goby FAQ enquiring about information with regards to a  
bony-snouted gudgeon, the other common names duckbill sleeper and crazy fish were also mentioned. This fish is Butis butis, the person  
asking wasn't sure because of the colouration, Butis butis can change colouration to match it's environment so its quite variable and most  
likely was the source of confusion. They're an ambush predator that generally feed on small fish and crustaceans, and will generally only  
take live food. They're from the tropical Indo-Pacific region and found in fresh water right through to marine conditions (low to mid  
range brackish seems to be optimal). They like lots of overhanging cover to hide and ambush fish from, I find that mine is particularly  
fond of branches, it spends most of its time upside down clinging to the underneath of the branches in my tank watching the small fish swimming past, waiting to pounce.
I'm guessing the information request is somewhat dated now so this information probably wont be a huge help the person who was asking  
but maybe it will help someone in future if you can update the FAQ.  
If you have any further questions about this amazing fish I'd be more than happy to help out.
Regards
Kari.
<Thank you much for this input. Will post along with... Bob Fenner>

Peacock Gudgeons - Feeding Fry - 12/18/2005
Hello,
<Hi, Jocelyn!  Sabrina with you, today.  I apologize for the delay in response - responded on your thread on our forums, as well, some days ago.>
I was wondering if you knew whether or not Tateurndina ocellicaudus (Peacock Gudgeon) fry would take frozen rotifer food?
<Mm, I think it unlikely.  I would use newly hatched baby brine shrimp.>
My peacock gudgeons spawned on Saturday, and now that the babies are developing but not hatched, I need to find food for them ASAP. A little late to think of it I know, but I thought getting microworms would be easier than it actually is.
<Indeed.  BBS is your best bet, here.>
So now I'm trying to find alternate solutions. If you have any suggestions I'd really appreciate a response.
<What are you feeding the adults?  I had tremendous success with mine and Spectrum marine pelleted food.  Apparently, they rarely take prepared foods, and when they do, VERY rarely spawn on prepared foods - I fed mine Spectrum exclusively (tried many others, as well) and (much to my dismay) the fish bred like clockwork.  They were in a tank at work - I was trying to get them NOT to spawn!  Fish will do as they intend, I suppose.  Beautiful animals, aren't they?  Almost like a killifish.>
Thank you,  -Jocelyn
<Wishing you well,  -Sabrina>

Sleeper Goby, Zero Info - 11/03/2005
My sleeper goby is vertical in the tank. He seldom moves his tail. The other fish in the 75 gal. tank are all well. It is almost as if he is standing still.
<First.... please.... everyone reading: capitalize beginnings of sentences, names.... Second.... Keith, there is just not nearly enough information here to go off. Please start by reading some of the articles and FAQs already archived on the site, about water quality, health and disease, gobies....>
Thank you. Keith Stimac
<Wishing you well, -Sabrina> 
<<Thank you for fixing, Sabrina.  Marina>>

Bichir and Large Marbled (Sleeper) Sand Goby...Can they be friends? 8/15/05
I have a 55gal tank with a large (17+in) Marbled (sleeper) Sand Goby in it. He has been in it for years spending time with just his feeder fish friends, and nothing else. I recently purchased an Ornate Bichir and have him in his own 30gal tank. He too just has the company of feeder friends. Is it possible for the two to co-exist when the Bichir gets a little bigger( in the 55gal of course)? If so how big should he get before I try it. He is about 9" now.
<Mmm, possibly... the goby, being in too small a volume, only kept with intended food fishes, may attempt to eat the Bichir. Bob Fenner>

Goby ID  7/13/05
Hello there,
<Hi, Pufferpunk here>
I just bought a goby. The store said it was a Blue Gudgeon Goby. When I look it up on internet and click on a site the picture doesn't look like the one I just got. It has a few blue stripes on its head and neck and blue spots on its tail both sides. Could you please tell me the exact name on this goby? Thanks Cody
<Try looking up purple spotted gudgeon, Mogurnda mogurnda or Mogurnda adspersa.  ~PP>

Breeding The Marbled Goby
Dear Bob,
<Edgar>
I have tons of questions about marbled goby since it caught my attention that seems nobody can breed them in captivity.
Can they be breed in aquarium ?
<As far as I know, Oxyeleotris marmorata has been in captivity: http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=5376&genusname=Oxyeleotris&speciesname=marmorata
This is an important food/aquaculture species in S.E. Asia>
what's the different between male and female ?
<Perhaps a difference in girth during gonad maturation?>
do they breed like gudgeon ?
<I suspect you are correct here>
how come I couldn't find this information on the net?
<It may be "proprietary"... a business secret... or likely, a matter of scientific, rather than hobbyist interest... You might try a large/college library search: http://www.wetwebmedia.com/litsrchart.htm>
I've search all over the place and now I plea for your help.
Edgar Tjai.
<Perhaps you will be the one to do this, write it up... Bob Fenner>

Freshwater fish identifications, ChuckR
Hi there
I need to identify two fish to find out more about them.
The one was called a "black widow" in the shop I bought it from. Its shape is very similar to a silver dollar. It is mostly black on the top half of
its body and the tail is silver. Aprox 2cm long. I've looked everywhere for information on this fish but can not get anything, except black widow tetra,
which I do not think it is. (saw a picture somewhere)
< The black skirt tetra is sometimes called the black widow tetra. If this is not your fish then you will need to provide more info like a photo.>
The other fish is definitely a goby, no doubt about that. It is white with black spots, and a small black "stripe" at the back of its top fin. The
sizes are aprox 3 & 5cm each. The shop owner said its a spotted goby and that the female is the bigger one of the two, but alas, I can find no
information/pictures on what it actually is. It is a very shay fish.
<Look at photos of the knight goby (Stigmatogobius sadanundio ). Males have longer fins.>
Both are freshwater fish. I've got two male guppies in the tank and sometime during today, the one lost half of its tail fin.
I doubt that it will be the "black widow" because they've been sharing a tank for 2 months now.
< The gobies are capable of biting the tail of smaller fish thinking that they are food.-Chuck>
Any help would be greatly appreciated.
Thanking you in anticipation.
Jaco
Ps. If it is a stupid question or I can find the info somewhere else, please
tell me so.

Freshwater fish identifications, BobF
Hi there
I need to identify two fish to find out more about them.
The one was called a "black widow" in the shop I bought it from. Its shape is very similar to a silver dollar. It is mostly black on the top half of
its body and the tail is silver. Aprox 2cm long. I've looked everywhere for information on this fish but can not get anything, except black widow tetra,
which I do not think it is. (saw a picture somewhere)
<Likely a Black Skirt Tetra... there are varieties, differences within this species: http://freshaquarium.about.com/cs/characins2/a/blackwidow.htm>
The other fish is definitely a goby, no doubt about that. It is white with black spots, and a small black "stripe" at the back of its top fin. The
sizes are aprox 3 & 5 cm each. The shop owner said its a spotted goby and that the female is the bigger one of the two, but alas, I can find no
information/pictures on what it actually is. It is a very shy fish.
<Maybe a knight goby: http://www.wetwebmedia.com/BrackishSubWebIndex/bracgobioids.htm>
Both are freshwater fish. I've got two male guppies in the tank and sometime during today, the one lost half of its tail fin.
<Could be from either of the above>
I doubt that it will be the "black widow" because they've been sharing a tank for 2 months now.
Any help would be greatly appreciated.
Thanking you in anticipation.
Jaco
Ps. If it is a stupid question or I can find the info somewhere else, please tell me so.
<Be chatting, Bob Fenner who encourages you to investigate before you buy livestock>

Feeding Peacock Gudgeons - 12/15/2004
Hi,
<Ahoy thar, matey!>
I have four peacock gudgeons, but I am having trouble feeding them.
<Not exactly uncommon.  These can be finicky feeders.>
They are in a tank with about 25 Neons.  At feeding time, the Neons go crazy, scaring the poor gudgeons away.  
<This is very definitely a problem.  You may find that the two species simply are not compatible.>
Any suggestions about how I can get some food to the gudgeons?
<Well, first off, the gudgeons may simply refuse prepared foods.  It can be a touch tricky to get them to take anything other than live foods, at first.  I got my pair onto Spectrum marine pellets rather quickly; it took them a few days to understand that it was food, but once they tasted it, they ate with gusto.  On top of that, they have been breeding like clockwork on just the spectrum.  Definitely offer them a very high quality food, or start them with live foods if all else fails.  Some ideas to keep the Neons at bay - feed the Neons a floating food on one side of the tank, and the gudgeons a sinking food on the opposite side (Spectrum sinks, by the way).  If necessary, divide the tank.  Best option of all is to remove the gudgeons to their own tank - but be aware that if you have a male and female, they will establish dominance over the other two gudgeons and possibly cause some harm.  These are beautiful fish, and well worth the bit of effort it may take to get them eating.  Good luck with them.>
Thanks,  Nate
<Wishing you and your gudgeons well,  -Sabrina>

Bulging Dragon
Hi, I was recently on your web page and noticed that you have a lot of info on dragon gobies. Well I bought one about 4 weeks and it is doing really good, he eats, swims along the bottom and has no apparent health problems. He is in a 20 gallon community tank and when I bought him I noticed a bulge and it did not hinder him and it is still their and it has only gotten a little bigger. So I was wondering if you could tell me what this bulge could be, how long dragon fish live and any possible way to breed them.
Thank you for your time,
Stephanie
<Hi, Don here. Hard to say what it is by the simple description you are giving. But it is never wise to bring home a pet that you know is not healthy. In fact even fish that look healthy should be put in a QT tank for a month before they go in your tank. Now that I got that off my chest, is the bulge localized, like a small marble under the skin, or a more general swelling? A marble like bulge could be a tumor which you can do nothing for. A more general swelling would point to an internal infection of some sort. It could be bacterial, protozoan, or even worms. Since I believe these are all wild caught fish, it could be anything. Another possibility is incorrect water conditions. These are brackish fish. They would do well with other salt loving fish, like Mollies. Keeping them in freshwater will cause health problems. Not sure of life spam and I do not think they have been bred in captivity. Did not see any breeding info in my brief search.>

Violet Goby Aggression
Hi, I just have a question that I've been wondering about for awhile.  I
have two violet gobies that are both 11" long (they started out at about
three inches long a year ago) in a 50 gallon tank along with a clown knife
fish, a fire eel, spiny eel, and ropefish.  I'm moving the other fish to a
130 gallon in a week or so and turn the 50 gallon into a brackish water
setup.  The nitrates, nitrites, and ammonia are all at zero and I add salt
after every water change (25% once a week with a gravel vac).  When I first
got my dragonfish they were completely friendly and stayed together all the
time.  They still stay side-by-side constantly and act as if there aren't
even any other fish in the tank (they stay to themselves) but,
occasionally, they bite at each other.  They'll be motionless one moment,
then one will suddenly start pulling on the others tail or bite his body.  
Their bodies don't actually get damaged, but their tails and fins get a bit
ragged.  I figured that they do this because they might both be males and
have become territorial once they matured, but then wouldn't they stay at
their own areas of the tank instead of cuddling?  Are they maybe male and
female and this is some kind of a mating ritual or something?  They also
love digging into the gravel to make caves and dens, so maybe they're trying
to create nests?  I was just wondering if maybe you had some answers.
< There are no known external differences between the sexes and they have never been spawned in captivity. They are territorial and well known for their ability to bury themselves in soft sand. Your observations may be a courtship dance leading to spawning or just two males settling a dispute over turf.-Chuck>
Thanks.
Dayton

Freshwater Jawfish???
hi there,
<Hello>
i recently read in the TFH magazine about the Jawfish. i found it's decorating behaviour very interesting. this little fish would be just a reason for me to set up a saltwater tank if i would have the possibility. my favourite place in the house is in the armchair next to the fish tank where i watch the fish while reading or just to switch off my mind.
<I can/do relate>
i am keeping freshwater fish/ coldwater species. even though i am living in Queensland/ Australia i do not heat the tank or the room the tank is in. the result is that the water temperature drops to ~14 degrees in winter because it gets quite chilly here during the night. on the other side in summer the water can get around 32 degrees easily. i keep a bristlenose pair together with a school of 5 duboulayi rainbows which we find in our surrounding waterways, a "left-over" goldfish and 5 bitterling with their mussel in a 4 feet/~170l (42gallon) tank. my fish are doing fine for years. they are growing and breeding although i don't try to hatch the eggs and show their best colour.
<Likely partly due to the thermal fluctuation...>
so far i found out that the Jawfish belong to the gobies and in that family there are marine and freshwater fish. is there anything similar in behaviour to the yellow-headed Jawfish for the freshwater aquarium?
cheers
Silvia
<Mmm, strictly speaking, all "Jaws" are marine: http://www.fishbase.org/Summary/FamilySummary.cfm?ID=366
but as you point out, there are fish groups, namely the Blennioids and Gobioids that have freshwater and brackish members that do display many Jawfish behaviors (digging, burrowing... though not mouth-brooding). You might direct your attention to some of these found there in Australia. There are a few good reference works on native fishes around you... as well as resources like Fishbase.org that can be searched by region and water type. Bob Fenner>

Mogurnda mogurnda!
Hi- I'm trying to find information on a particular type of goby called a mogurnda, mogurnda. I need to know the Latin name for this fish.
<Hope this isn't shocking....  The Latin name is (genus/species)....  Mogurnda mogurnda!!  Really.  I'm not kidding.  Here's the Fishbase info. on this fish:  http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=22759&genusname=Mogurnda&speciesname=mogurnda >
He has very unusual eyes- kind of a bluish-green. I was told he comes from S. America.
<This species, no.  Most freshwater and brackish gudgeons/gobies are from Australia and New Guinea, some from Asia....  A handful of South American Gobioids, like Dormitator maculatus, do show up in the hobby>
Thank you. Lisa Griffin
<Any time, Lisa!  Wishing you and your goby pal well,  -Sabrina>

Jade goby illness
<Hi Laurie, Pufferpunk here>
Good morning crew.  I happened upon your site this morning looking for information on the jade goby.  I am getting sorta desperate.  I have a 150 gl with two (2) 450 Fluval media filters.  Natural gravel and plastic plants.  I have put lava rock, slate and lots of interesting rocks (cleaned well before adding) to the tank over time.  It houses a variety of Africans and includes a rope fish, a fire eel, a spiny eel (hand feed - I love that) and a jade goby.  The goby seems to have constant eye problems.  It started on his fins and I suspected high ammonia as he spends a lot of time on the bottom, but that is not the problem.  
<How long has this tank been set up?  What are your ammonia & nitrates?  For healthy fish, they both should be 0.>
My eels and pleco are fine.  Only the goby.  It seems to get better with treatment, but then reoccurs and is now pretty bad.  Mostly just one eye.  Typical cloudy eye as appears with typical fungus/infection.  I can not seem to get it cleared up.  I have treated the tank several times with an antibacterial tea tree extract that usually works well on any fin rot or wounds in the past.  
<Are you using Melafix?  That is what I would recommend.  Also lots of water changes, until you have 0 ammonia & nitrites.>
All my fish are fine except the goby.  I would really like to find something or method to treat and get him well.  I love my sleeper and hate to see him suffer.  Need some advice on what to treat in this large tank that will not affect my eels.
<Keep treating w/Melafix for a week after the eye clears up.  I buy the stuff by the gallon.  It's made for ponds, but you can use it on regular aquariums. With a tank that large you'll need it, unless you have a cycled hospital tank you can doctor your goby in.  You still need to clear up that ammonia, it's not good for any of your fish.  I do 50% 7-10 day water changes on all my tanks, cleaning the gravel as I go.   If they aren't used to that, you should start with 25%/day, until you have the ammonia level at 0.>  
<Good luck--Pufferpunk>

PP puffer treatment, garlic
<Pufferpunk again>
Thanks for the reply.  My ammonia is 0.  
<Then why did you suspect ammonia as the problem cause?  Are you testing before or after water changes?>
I have a lot of fish so monthly
gravel clean/water changes are done faithfully.  
<Monthly isn't often enough.>
Yep, MelaFix is what I use.  
I too use a lot.  Nitrate... will look further into that.  I also increased
the temp and added more salt in-between MelaFix treatments when I suspected
the eye of starting to cloud.  I am thinking that a hospital tank with
higher salt content??  I have also been told to garlic soak my sleepers food
to increase immunity for future.  What is your take on the garlic.  Thanks .
<I've never used garlic.  I've heard pros & cons on the subject.  Some folks swear by it & others think it's a waste if $$$. From what I've read, some say it has helped w/internal & external parasites.  See: http://store.yahoo.com/inlandreef/garxtrem1oz.html.  I'd increase water changes, as cloudy eye is a sign if poor water quality--Pufferpunk>

Fishbase locked? (also goby compatibilities)
Fishbase.org is a closed site now! Whatever will I use for learning about my fish anymore! *Overreacts* Eh, hypocrites.
<you are mistaken here, my friend... it is open and we have been using it all night. I just tried it from the main, German and French servers. Do check again.>
In any case, I was looking to figure out a bit more about a dragonish, aka Gobioides broussonenti.
<read more here (follow all links at bottom too):
http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=3856&genusname=Gobioides&speciesname=broussoneti >
When I first saw the oversized goby, I figured it was an eel in any case. The question is if these gobies are aggressive or not.
<they are not... instead they are difficult to feed/keep planktivores>
My mollies and my Tiretrack eel are flourishing in a very low end brackish aquarium,
<you will need this or more salt for this goby>
the eel devouring blood worms like nobody's business and even growing half an inch to an inch in only a week. What I'm wondering about is if there would be a conflict between this 5.5" eel and a dragon eel goby which is about 6" or 7" long and considerably wider.
<perhaps... but more importantly, the goby will be outcompeted if not intimidated by the active feeding of the other fishes. It is an inappropriate mix. Please resist>
The people at the store (PetCo, figures...), completely uneducated as to what fish they even had, were not much help as to giving much info. I was the one to re-educate them as to what they even were carrying, but still I don't know what kind of behavior I would expect from it. In my high end brackish aquarium my two small bumblebee gobies have the audacity to compete for food with the larger green spotted pufferfish, which gives me the impression that a dragonish would also be aggressive when it comes to food, and more importantly, territory.
<neither is true/correct>
There are tons of little holes and caves where the Tiretrack eel hides (Road kill is his name btw), and apparently dragonish don't seem to like to hide anywhere in the tanks at the store. Can I safely house this big guy or would I just be better off getting a couple of the knight gobies that I have been eyeing lately.
<the knight gobies are much better choices... hardy and tolerant>
P.S. I finally put in a couple of new 10,000K fluorescent bulbs to fix my plant degradation, and now there is almost a mutagenic growth going on in there. In only a matter of 2 days sword family plants have grown at least 2 inches and my wisterias have gone from twigs to pine trees. Thanks for the reference to that.
<best regards, Anthony>

Gobioides broussonenti
Hi Bob, A little helpful info for you concerning the Violet Goby. The greatest difficulty in keeping this fish is to adjust your salinity until it is suitably "brackish". Feeding these fish is a breeze because they simply love brine shrimp pellets. Very fascinating species, hardy and a lot of fun to observe. They are so ugly that you cannot help but like them.
Scott Hill
A fish enthusiast!
<Outstanding! Thank you for your input. Will post... and can assure you, you have saved many of these fishes from short, hungry stints in aquariums. Bob Fenner>

Knight Gobies - Suddenly Dead (03/03/03)
Hi,
<Hi. Ananda here, unhappy to hear that someone had bad luck with one of her favorite types of fish...>
I have a mystery that I am hoping that you can shed some light on.  
<Will give it a shot...>
I have a 30-gal freshwater tank that has 4 dwarf Gouramis, 2 Bala sharks (recently moved from another tank), a 2 month old rosy barb, and 2 knight gobies (until yesterday).  The tank set up is relatively new, about 1 month, but the rocks and some of the plants came from another tank that has been running for over a year. (No sick fish there)  
<When did you move the rocks and plants? When you started the tank? Or just recently?>
I have been feeding freeze dried bloodworms, brine shrimp, and slow sinking pellets.
<I'm not a fan of brine shrimp, except when they're used to entice fish that otherwise won't eat... your fish should have a bit more variety than this.>
Last night I discovered both gobies dead side by side on the bottom of the tank.  When I removed them from the water they looked as if they had been dead for several days.  Their fins were badly decomposed.  
<Hmmm. Badly decomposed, or perhaps nibbled-upon?>
The mystery is that they were alive earlier in the day (I feed some brine shrimp and watched everyone eat for a while.), and showed no signs, that I could tell, of illness.  I have closely examined all the other fish, and they all look fine.  All the fish got along well, and I never saw any evidence of the gobies being harassed by the others.  
<I am curious about your water quality -- ammonia, nitrite, nitrate, pH, temperature... the gobies, being scaleless fish, were the most sensitive of the bunch when it comes to water quality. I would do a water change immediately to deal with any possible ammonia.>
Should I worry about the others?  What would cause them to die suddenly, but not harm the other fish?
<Ammonia, nitrite, or nitrate poisoning would affect those fish first. The others might not be out of danger, which is why I'm suggesting a water change ASAP. Another possibility -- the rock you took from another tank -- was it ever in a tank that was treated with a copper-based medication? Gobies and other scaleless fish can not tolerate copper.>
Any help you can give would be appreciated.  I'm really worried about my other fish.
<Understandably so. Do check out the various freshwater FAQs and the WetWebFotos chat forums. --Ananda>
Laura Crouch

RE: Knight Gobies - Suddenly Dead (03/05/03)
Ananda,
Thank you so much for your input.  
<Glad I could help.>
The rocks were moved when I started the new tank.  (They were white and my Pictus Cats did not like them so rather than throwing them out I decided to recycle them.)  I think you may have hit upon something with the rocks.  I had to treat for Ick about three months ago.  I would never have dreamed that it would harm anyone.
<Many things we put in our tanks have the potential to harm fish -- even those that are designed to help fish. With any scaleless fish -- gobies, loaches, puffers and others -- you need to be especially careful what you add to the tank. You could probably save the rock by putting it in an empty tank with a Polyfilter.>
I did a complete water change last night and replaced with new rocks.  Everyone else still looks happy and healthy.  I am going to let the tank run for a couple of months before I add any more fish.
<Sounds like a good idea to me.>
Thank you!
<You're welcome. --Ananda>

Knight Gobies
Hi,
I have some Knight Gobies that spawn on a regular basis. I get the eggs to hatch, but can't keep the fry alive any more than about 2 days. I use infusoria to feed with. Can you advise.
Thanks and God Bless, Ed
I will forward this message to a friend of ours...Dr Sallie Boggs. She is a brilliant aquarists and grand master breeder (national accolades) with a flavor for gobies and blennies. Best regards, Anthony>

Re: Knight Gobies
I had the same experience when my Knight gobies were breeding. Then I did not have a culture of rotifers. Now I have rotifers I use for marine fish and no breeding gobies. I believe the goby fry could eat the rotifers . Both gobies and rotifers like brackish water. Rotifers can be obtained from
Reed Mariculture or Florida Aqua Farms or a friendly marine fish breeder. If you live in Pittsburgh area you can get them from me. Sallie

Fear, Fish Behavior
I have a 5.5 gallon tank with 4 balloon mollies and two bumblebee gobies. The Nitrite levels are good, the ammonia levels are good, I have added salt to the water, and the pH is fine. The mollies eat fine, but the gobies just seem to hide, and are not eating. I do feed live foods as recommended. Is there a chance the gobies are afraid of the mollies, and thus want to keep a low profile? Thanx. James Kim
<in such a small tank, yes... the gobies may simply be intimidated by the activity of the more assertive fish. But admittedly, they are not gregarious fish to begin with. Anthony>
PS How long before the gobies die?
<shouldn't let them go more than 5-7 days without food. Do move them to another tank or trade them back, please>

mainly brackish gobies
Hi Bob!
Well, the spinning molly died a couple of days ago. She wouldn't eat,
even when I tried live black worms, so I wasn't surprised.
<Sorry to learn of your loss>
The ghost shrimp experiment is going well. They seem to be tolerating
the SGs up to 1.008 without much difficulty once they get past the
initial transition period. Some of them haven't survived the transition,
but in those cases, the gobies haven't complained about the extra
treats. Oddly enough, the candy-striped gobies aren't interested in the
shrimp, even though they are easily large enough to eat them. I had an
entertaining time watching one of my so-called "butterfly gobies" trying
to eat a ghost shrimp that was bigger than itself. The shrimp got away
for a while, and then goby was "stalking" the shrimp. Quite amusing. I
don't know what the "butterfly gobies" really are, but they definitely
aren't true gobies. They look sort of like miniaturized dwarf lionfish,
mottled brown and beige and about 1" long, and nothing like the marine
butterfly goby, Amblygobius albimaculatus. Do you know if this fish is a
sculpin, or a scorpienidae, or is it something else entirely? 
<Beige mostly? Maybe Stigmatogobius: http://www.wetwebmedia.com/brgobioids.htm>
LMK if a
photo would of my fish would help; I don't have a photo of them yet
since it's hard to get the digital camera to focus on them (it's a bit
*too* automated).
<Check to see if you can "turn off" the automated (focus) feature... Bob Fenner>
Thanks,
Ananda

Ropes and Dragons
Robert,
I have a 45 gallon freshwater live plant setup. PH7.6 Hardness
apx10 Ammonia and nitrite at zero. I recently purchased two new rope fish
and a pleco (I think that's what it's called). 
<Mmm, maybe a member of the family of mainly South American Sucker Mouth Catfishes, Loricariidae: http://www.wetwebmedia.com/loricariids.htm>
The two rope fish died within
two days and a day later the rope that I've had for 6 months died.
<Not unusual to have new Ropes bring in disease, stress... Our coverage of this and the related Bichirs: http://www.wetwebmedia.com/bichirs.htm>
Then last
night my small dragon Goby died. The ropes got the "glassy" eyes and
discoloration before they died and the Dragon lost a lot of weight and
showed a large white section on it's tail before it died. So far the other
inhabitants haven't shown any problems; they are: a larger Dragon Goby
(about 6"), two Bala Sharks, 1 Clown Loach, 1 Pleco (algae eater), and
several neon tetras. I did a 20% water change and filter maintenance after
the first two died and I've been running my Diatom XL (normally for
polishing only) a couple hours a day. Any possibilities you can offer will be
greatly appreciated.
<I would do what you have done... and add some activated carbon/powder to the diatom>
As a side note. I have already purchased a cheapy 10 gallon setup to
use as a quarantine tank in the future. 
<Good idea>
You might also be interested to know
that the fish came from Pet not so) Smart.
<Yikes...>
Thanks Again
Tom Peterson
Kissimmee, Fl
<Sorry to hear of your trials and tribulations. Steady on my friend. You're moving in more positive directions. Bob Fenner>