Naked Goby Question

I am going to be collecting some naked gobies soon and my question is what is a good diet for them, and does thier size make a difference in thier diet.

AH! one of my favorite fish which I never thought anyone else ever kept.
They are very good eaters and will learn to take flake pretty easy. Typical frozen foods will do well.
Yes, they have small mouths and are small fish. Food must be sized appropriate.

An interesting fact I observed in the wild and in captivity; damsalfish and other marine species from the Caribbean can not abide the presence of a naked goby in their territory. They will hound it and attack it and make it's life miserable every minute. They can not survive in the same tank, no matter how big.
In our cooler New England waters [where naked godies stray infrequently], the fish filling the same niche, mostly temporate wrasses and juvenile sea bass, will completely ignore a naked goby and can share a tank with them.
My theory is naked goby are preditors of substrate deposited eggs and are the deadly enemy of substrate spawners like damsals.
The New England fish would never encounter a naked gody during breeding season.

Uh, nevermind. I answered my own question while asking it.
Just a bit of confusion about exactly which naked goby it was.

Edited by Mysteryman, 20 February 2009 - 09:26 AM.

Uh, nevermind. I answered my own question while asking it.
Just a bit of confusion about exactly which naked goby it was.

For anyone else confused, I was refering to is Gobiosoma bosc. I assume that's what the original post was about.
Here's a good article on naked gobies.naked goby

I'm bringing up an old thread so that others with the same question may be directed here.
I've read up everything on Gobiosoma bosc I could find (on the net and on this forum), and still have a question about salinity.
You can skip the gray text if you don't want to read a long story... My question will be in black below...

Whenever I go to see my sister in Mt. Pleasant, I swing by the ponds I posted about HERE to bring home plenty of grass shrimp to feed the warmouth and dollar sunfish. Since, I have seen a few more species including mullet. Although this pond is separate from the marsh, I am not sure of it's salinity given that I am finding mullet, mumichogs, rainwater killies, sailfin mollies, sheepshead minnows, silversides, etc. However, I am also finding Gambusia and the occasional bluegill.

I returned in late spring from collecting shrimp again I emptied out half of a 12 gallon tank (freshwater, and dumped the shrimp and their water in the tank. I used up all the shrimp and left the tank sitting in my office all summer while I was in the field, just topping it off with freshwater when I returned into town (thinking it was empty other than choked-full of java fern). I returned this week to find two 1 - 1.5 inch gobies in my tank. They are no doubt naked gobies. It also appears that they were first described in the marshes of Sullivan's Island (a few steps from the pond where I collected them - a picture in the following post...). They are one of the most interesting fish I've even kept. They are constantly darting around, chasing each other and hunting for bloodworms that has drifted into the roots of the java fern. They haven't accepted dried foods yet, but I am getting them in much better shape on frozen bloodworms. Neat fish for sure.

I have no way of testing this, but I am fairly certain that the tank has zero salinity considering how much freshwater I have put into over the last four months. The gobies have apparently survived, and grown - although they were quite skinny when I noticed them. I am assuming they fed on tiny snails, newly hatched shrimp and other critters that may have been floating around since their introduction.

So, my question is: has anyone cared for Gobiosoma bosc in full-freshwater? If so, can you share any information?
Second: Since java fern can tolerate smalls amounts of salt, I can convert this tank to slightly brackish. Anyone know what salinity levels these guys will do okay in? Any light shed on the subject is much appreciated.

Ponds in relation to the marsh between Mt. Pleasant and Sullivan's Island

Edited by UncleWillie, 20 July 2011 - 12:28 PM.

In all my years with NC Marine Fisheries, I don't think we ever caught naked gobies in totally fresh water - lowest was around 6 ppt but usually higher. But like a lot of oligohaline species I'm sure they can survive in fresh water as your fish have shown. The freshwater goby can be quite abundant in fresh water.

Check between your upper and lower lips - you might have a salinity meter between them. For most people, around 0.5 ppt is the point at which brackish water begins to taste slightly salty. Not sure about java fern, but i keep guppy-grass Najas guadaulupensis with brackish killies at 2-5 ppt. Also, just guessing here: keeping Gobiosoma at very low salinity (less than 2 ppt) long-term might cause other health problems and shorten their lives. In nature they can move to whatever salinity they feel they need.

>> I have no way of testing this, but I am fairly certain that the tank has zero salinity considering how much freshwater I have put into over the last four months.

Check between your upper and lower lips - you might have a salinity meter between them.

Haha, I am sitting at my desk now in front of my tank. Luckily my office mates didn't see me tasting my fish tank water. I am not getting even a slightest hint of salt. In regards to the health issues - I am picking up some salt and a hydrometer today and going to very slowly increase salinity over the coming weeks to avoid killing off my bacteria or fish. I've always considered keeping a brackish tank with rainwater killies (I've kept them in freshwater before), so I guess now I have an excuse to start getting a bit saltier.
Thanks for your responses.
I originally thought these to be freshwater gobies until I did a little research and saw the distinctive striping. After studying Google Earth, it appears the pond I scooped them up in looks like it has the possibility of having a culvert extending to the marsh - I never walked that far down to avoid getting in people's yards. The pond is the long, skinny one in the picture. This may explain the reason behind the numerous mullet, and no bluegill in this particular pond, while seeing bluegill, but no mullet or silversides in the neighboring pond to the west. Definitely have to test salinity next trip to the lowcountry.

UncleWillie, how have these guys done in your freshwater setup? I have caught a few of these in Galveston Bay over the years and am thinking about keeping some in one of my freshwater tanks. I noticed there are records of non-native populations in several reservoirs and inland river systems (Concho) in Texas, so it would seem like they could do fine in hard tapwater.

Also, does anyone know if naked gobies have a symbiotic relationship with pistol shrimp? I was finding a lot of them together in oyster clusters.