Violet Goby. Habitat... SW, BW...  - 03/30/10
I was reading through your info page on these fish the other day and at the cost of having you think me "ignorant" for debating, your demand that these have to be brackish fish is somewhat puzzling to me.
<Why? They certainly prefer brackish water conditions in the wild.
http://www.fishbase.org/summary/SpeciesSummary.php?id=3856
Gobioides spp. are adapted in various ways to tidal mudflats. For example, did you know they breathe air? Unlike other fish in mudflats they don't swim back and forth with the tide, but dig burrows in the mud. So even when the tide is out, they're in the mud, resting and waiting. During that time they gulp air. As soon as the tide returns, the gobies leave their burrows and start feeding. This allows them to get to food before other fish have a chance to swim up from the sea. Their burrows also allow they to avoid being seen by predators such as seabirds. Such habitats are often murky, so their eyes are useless. Most have very small eyes, and species don't have any eyes at all. In short, they're remarkably well adapted to this ecological niche.>
Now before you dismiss this out of hand, This is the third such fish I've raised in freshwater conditions and though I lost one during a move the oldest is currently somewhere around five and a half years and in all are in perfect health.
<I'm glad you've had success. But you've also been extremely lucky. By far the vast majority of specimens last just a few months in freshwater. While they may adapt to freshwater conditions for a while, almost always for one reason or another they eventually sicken and die.>
None have ever had any type of infection or difficulty of any real note and besides that the best fact that I can offer you is that it must indeed be possible for these fish to mate in captivity because 2 of mine did just that.
<Well done. This is not commonly reported.>
The babies were very small, no more than a few millimeters and floated in the current among the plants at the surface of the water.
<Likely the fry are planktonic, and require saltwater conditions to develop. The fry will certainly require extremely tiny live foods, comparable to those used to feed marine fry.>
They had an appearance almost alike to miniature tadpoles and almost completely clear.
<Yes, this is often the case with gobies.>
Unfortunately after about a week and a half or so they had all died. I'm assuming that this was due to lack of proper care because everything I read told me that this just was not possible and could never happen and so didn't give any info on the habits of the young so I had absolutely no clues to follow to successfully raise these babies.
<Breeding gobies is certainly possible but it is usually extremely difficult. A few gobies (e.g., Chlamydogobius eremius) produce large fry that are as easy to rear as guppies, but most produce very small, often planktonic, fry.>
Unfortunately as well it was one of the mated pair that died and so I'm doubtful that this will happen again ( at least with these particular fish). But I would definitely be hard pressed to believe that these fish cannot be raised happily in fresh water as mine are currently doing very well indeed have had no major issues.
<The fry are very likely marine, as most of these coastal gobies work that way. By having marine, planktonic fry the juveniles can be carried by the current to various estuaries and so extend the geographical range of the species. Since the adults are inept swimmers, the adults can't migrate any distance at all.>
The largest is currently just over 16 inches in length and to add to all that, fish do not breed unless the conditions are correct for them to do so (generally) and yet where most seem to think that you have to keep these as brackish fish and that they do not breed in captivity, I have raised mine in freshwater and they have indeed produced offspring.
<With brackish water fish this can be a very misleading approach. For example, there's a well known case from the 1970s where an American aquarist managed to breed Monos. His specimens were being maintained in freshwater. Now, if you try to keep Monos in freshwater, most of them will at best be nervous and poorly coloured, and at worst will simply die. But for whatever reason, this guy had healthy specimens and is the only person in the literature who's bred this species. If you think about it, Monos very likely do breed in estuaries and in freshwater, since that's where the juveniles are found. But the adults are unquestionably marine fish. So, you have to separate the fact the fish spawn in one set of conditions from the fact they live as adults in a completely different set of conditions.
Gobioides spp. may well spawn in freshwater or low-salinity brackish conditions, but the fry very likely develop in the sea, and the adults are found in coastal rather than inland habitats. Can they survive in freshwater? Yes, clearly some do. But is that the best, most reliable way to keep them? Certainly not.>
Anyways, just something to think over. Also I did try to photograph the young but they just wouldn't show up properly without any colour to them and are not discernable from their surroundings in the few photos I tried ( this could have been due to a lack of a good camera as mine is very mediocre). I have a 90+ gallon tank and not sandy bottom but quite small stones and he does filter these quite routinely without issue and also seems to enjoy digging large holes aside from his cave "house" and just generally digging up every plant I try to anchor down.
<Yes, they are diggers. As I stated above, in the wild they spend the low tide portions of each day in burrows.>
Very active and friendly, Follows me around the tank and swims over to greet me anytime I put my face to the tank. He even (and yes I know this is a no no) likes to have his forehead rubbed and will come to the top of the tank if I stand in the corner with a finger in the water and hang off the glass and put his head under my finger. Coincidently I also had two Discus that displayed this behavior.
<Fish can be friends, eh?>
So while I may do some things that are supposed to be wrong my fish seem to be just right.
<I'm glad you're enjoying this fish. But I cannot stress too strongly that luck has been on your side, and the vast majority of people who keep Gobioides spp. in freshwater tanks end up with dead gobies.>
D. Mathers
<Thanks for writing in.>
P.S. where the most common color I hear of for people to describe this fish as is grayish mine are gray here and there but mostly a very deep purple/blue with patterns of gold near the gills and down its flanks.
<There is more than one species in the trade. Compare Gobioides peruanus, which is mostly grey, with Gobioides broussonnetii, which does have pronounced purple bands along its flanks. Cheers, Neale.>

Re: Violet Goby, sys., repro.    4/5/10
Thanks for your reply Neale,
<My pleasure.>
I found quite a bit of that information to be very interesting.
<Good.>
I was thinking somewhat along similar lines to what you stated as to the possibilities of breeding but was by no means sure.
<I'm not "sure" either since I don't know anything about the reproductive ecology of Gobioides spp., but I think we can safely hazard a guess by looking at other intertidal brackish water gobies.>
It was quite unexpected when it happened I can say that much. I Understand also what your saying about the fresh/brackish water issue and why you would stick to the most likely option for success for passing out advice.
<It would also be better for your goby to be kept in brackish water, too.>
I guess when I read that over and over again I didn't consider having to deal with trying to teach the masses the easiest way to keep their fish alive ( I know, whole point of the article right).
<Right. And still the best way to keep Gobioides spp.>
So I apologize if my statements seemed a little hostile in that regard.
<No problem. Cheers, Neale.>
Re: Violet Goby   4/5/10
Sorry that last mail got sent unfinished.
<Oh?>
I was wondering though if you would have any further recommendations for raising the fry should I happen to have the chance again.
<Breeding most gobies is difficult. I know nothing about this species, so in all honest you're going to be making things up as you go along. The fry are likely extremely small, so your first job will be setting up a culture of marine infusoria. You'll also need to transfer the fry from freshwater to marine conditions. Ideally, the more brackish the water in the breeding tank, the less stress you'll place on the eggs when moving them to the marine tank.>
For instance if I set up a small Brackish tank it would obviously be best as a well established tank when they went in.
<Sort of, yes, but I doubt even a mature tank will have enough plankton for the fry to eat. So while keeping a marine aquarium running will be part of the process, and live rock will produce some food, you'll still need to culture marine plankton.>
Are there any brackish fish you would recommend that I could set up a tank in advance with that wouldn't trouble the fry while they are growing.
<None, really. By definition, a breeding tank will need to be empty of fish. You're likely going to need very gentle filtration, e.g., a sponge filter or maybe just an airstone and some live rock if you go marine.
Adding tankmates will complicate things.>
Also If you know anything further about what they would eat I would appreciate any info you could pass along on the subject.
<Do read here and elsewhere re: breeding Neon Gobies, Dormitator maculatus, and Stigmatogobius sadanundio since these will all be relevant here.>
Thanks for your time.
D.Mathers
P.S. I might not go so far as to call my Goby my friend but just calling it my pet doesn't sound right either so... /shrug.
<Cheers, Neale.>

Sexing Violet Goby 9/29/05 <Hi, Pufferpunk here? Excuse me but do you know how to tell whether a violet goby is a boy or girl. Thanks in advance. <Sorry, but only the goby knows for sure.  Are you keeping it in brackish water?  ~PP>

Dragon gobies    5/21/07 I know that there isn't much info on these fish but I know that more is  being discovered. <There's actually lots about these fishes in the aquarium press. Take a look at the Aqualog brackish water fishes book, or perhaps my one from TFH. Goby scientist Naomi Delventhal covered this species in considerable depth in her chapter on gobies.> I went to Wal-Mart (yes, bad idea, but I had to rescue  them from there) and bought 1 dragon goby, a 10 gallon tank some rocks  and plants. <10 gallons far too small. A healthy specimen will reach 30 cm or so within the first year, and up to 50 cm when fully grown.> Cleaned all and put him in. At the store he was all swimmy but once he settled in he became secluded (which I know is common) what I'd like to know about are his uncommon traits. The water is not brackish, yet he seems to be doing fine. <These are indeed hardy fish, and will tolerate freshwater conditions for long periods. BUT NOT FOREVER.> His tank mates are a snail, a Pleco, 12 swordtails (male and female), a very docile female crown beta that itself is very social, and some unknown number of ghost shrimp. <None of these fishes are really suitable, except maybe the swordtails, which will do okay in brackish water at SG 1.005. Swordtails don't like brackish water, but at low salinity it won't harm them.> Now, I didn't notice him eating before, but noticed he's been living for a few weeks now and my shrimp population is dwindling... <When starving, dragon gobies will eat shrimps and small fish. Their normal and preferred diet is a mixture of infaunal invertebrates (worms and insect larvae, for example) plus algae. They also filter feed from the water (live brine shrimp are ideal). It is likely you are not giving the goby enough food to eat, and since he's hungry, he's eating what he can. Bear in mind that when properly cared for these are NOT PREDATORY, and people have kept them with even guppies and not lost any fish.> So, someone suggested I feed him algae wafers, so I did which he seems to like. (He does the whole gulp and inhale nibble thing). <Quite so. The little teeth in his mouth are for scraping algae from rocks. Try offering some fresh algae, e.g. sushi Nori, and see if he goes for that.> My questions being, One: if my swordfish mate, will he eat the eggs? <Swordfish don't lay eggs, they produce live babies. If properly cared for the goby will ignore them, but if hungry he will eat them. But your swordtails will do that, too.> Two: even though he is doing ok in freshwater, should I put him in brackish anyway? <Yes, he needs a bigger, brackish water tank. At least 30 gallons, and ideally 55 gallons.> Three: I know this is asked a lot, but how can I mate the dragons (hoping for new info)? Do I just buy many and hope for the best? <Not been done yet, and probably complex. Many of these brackish water gobies lay eggs in burrows but the baby fish are planktonic, drifting around in the sea for a couple of months. Anyway, the first step is getting a group of them. They are territorial. In  a big tank people do keep them in groups, and they are quite fun like that. The fish "fight" by lining alongside each other, and push one another to see who is the strongest. Either way, each fish must have a PVC tube burrow of its own.> Four: should I put my goby pal on a diet and try to feed him live food vs. wafers? <He needs BOTH. They are filter feeders AND algae eaters, so doing just the one thing is wrong. A mixed diet of frozen bloodworms, live brine shrimp, and algae pellets is an excellent starting point. Watching them filter feed the brine shrimp is terrific fun -- they swim in the water, gulping the brine shrimp into their huge mouths like baleen whales!> Thank you for your time! -Dave <No problems, and good luck.>