Sleeper Goby sifting substrate
>I have a 120g reef system, 90g display tank with a 20g refugium and 10g sump.  I have fine aragonite substrate, about 110 lb live rock, 14 corals, one anemone, 10 fish, 3 shrimp, a feather duster worm and a load of hermit crabs and snails.  The system is running perfectly, water quality excellent, fish healthy, most corals growing like mad.
>A few days ago I introduced a 3-inch Orangespotted Sleeper Goby (Valenciennea puellaris) after almost a month in a quarantine tank.  Well, he seems to be doing fine, but he sifts through the aragonite continuously, which causes silt to be circulating all around the tank.  The tank is now cloudy with due to these swirls of substrate, and the beautiful purple live rock has now become largely silted over.  It looks terrible, and I also wonder if the corals are now getting adequate light.
>>It's creating *that* much silt, eh?  Sounds as though he's having the time of his life.
>Catching and removing him is problematic; he is so fast it was difficult catching him in an almost bare 20g quarantine tank.  There is no way I could catch him in the big tank without dismantling the entire reef.  Any suggestions?
>>Hhmm...well, if he were an invertebrate that didn't swim I'd suggest the jar.  If he were a damsel, I'd suggest a tiny, barbless hook.  I don't think we should have you use that on the goby, though.  So, if it were my tank and my fish, I'd first try to sort out how to reduce the siltiness (I wouldn't worry too much about the corals not getting enough light, unless there's not enough current to move the silt off them).  Barring that, I would do some rearranging of the tank, so that I could block off a portion of the tank to trap the goby, thus making it easier to catch him.  If you absolutely cannot rearrange the tank to afford this opportunity, then I would find myself the oldest fish shop hand I possibly could, and offer him/her $20 to come and catch the fish.  Other than that, you could try some fine netting and literally "recollect" the fish, this could take some wrangling as they usually need to be chased from the rockwork.  Sorry I can't be of more help, though I think that someone skilled in netting up fish might be able to do it.  Good luck!  Marina
Jeffrey M. Zegas

Twin-spot Goby
<Hi Kylee, Mac here>
I was talked into getting a twin-spot goby without doing the proper research and now that I've researched it I see that they need to be kept in pairs. My question is should I go get one from a store that isn't a mated pair and see if
they will pair up? or should I take back the twin-spot goby that I have.  <In all honesty I kept a single twin spot goby for two years by itself.  I know that it is recommended that you keep it as a pair but mine did quite well on its own.  I will say that it paired up with a shrimp goby.  It was probably one of my very favorite fish ever but it did constantly eat in the sand.  Constantly sifting sand through its gills.  Was nice for keeping the sand stirred up but was tough on the sand critters.>
Also will the twin-spot goby compete with the mandarin for food?  <Both eat pods so it will provide some competition for the mandarins food source.  You might consider supplementing your pods production with some type of refugium where they can breed without being eaten or consider renewing your pods with some type of outside pods that you bring in.>
Thanks,
Kylee

Valenciennea puellaris and Amblyeleotris guttata compatibility  11/17/05
I had a Valenciennea puellaris that jumped from my tank, so I had my LFS order another, but his supplier sent him Amblyeleotris guttata instead. 
<Not unusual to have suppliers mix gobies up>
My questions are: 1) would these 2 fish be compatible in a 135g system? 
<Mmm, yes, should get along>
Since the diamond watchman and the spotted prawn look so similar, I didn't know if that might cause them to fight. 
<Not likely>
2) I believe I had sufficient 'pods for the puellaris (they are -everywhere- both amphipods and copepods, very easy to find all over the rocks, glass, sand, any time of day). I have about 3-4" of sugar-sized sand throughout, and the live rock offers a lot of places for things to hide (very porous and stacked to make crevices). My concern is if they both eat 'pods that I would not have enough. I planned to add a refugium within the next 2 months, but do not have one yet. Would these two fish compete for food?
<Not to the point of starvation here>
3) I know the puellaris likes finer sand than the guttata - would it be possible to put some more coarse sand/gravel on one side for the prawn goby and keep just the finer sand at the other end for the puellaris to encourage them to stay on different sides of the tank?
<I would not add, mix the substrates>
Thanks!
Scott Hardin
<Try as the system is currently. Should be fine. Bob Fenner> 

Mandarin/Diamond Goby question   6/10/06
I have a question or two for you.   I have 110 Gallon tank, with about 90 lbs. of live rock.  I am planning to run the tank approximately 6 months to a year before adding any piscine buddies; I really want to let all the critters populate the rock and sand.  Question; would this amount of time provide enough live food to sustain a Mandarinfish (Synchiropus splendidus), without a refugium?
<Likely so... with an absence of competitors>
Would he/she eventually eat through all the pods, or would they have enough space and numbers to sustain a healthy population indefinitely?
<Likely large enough to sustain an ongoing food population here>
I suppose I can make refugium area in my sump, but I don't want to light it since I tend to have heat issues and that is just one more source to worry about.  Can the pods grow fine in the dark?  
<Many types, yes>
Actually, it is not completely dark since it is in a fish room and receives stray light from the tank above, but definitely not enough "quality" light to grow any macro algae with.  I can put some aragonite sand and some filter floss for them to live in....would this work?
<Possibly>
Last question; this is regarding a Diamond Goby.  Would that be in competition for food with the mandarin goby?
<Particularly when small yes. Still as a consumer of benthic, in-fauna that give rise to other organisms with age, size as well>
When they filter the sand, do they specifically target pods, or are they just getting the detritus?
<Sift most all "large-enough" worms, crustaceans, molluscs...>
Thank you for your time, it is appreciated.  Take care.
Paul
<Bob Fenner>

Goby Dust…The “Engineering” Nightmare? – 03/06/08
Crew,
<<Ben>>
Thank you in advance.
<<Happy to assist>>
I recently added a Diamond Goby to my 240. I made sure he was eating at the LFS for several days before getting him and he continues to eat well at home.
<<Excellent>>
After finally adding him to the display after QT he is now "going to town" on my sand.
<<Indeed…and likely “crop-dusting” your rock/corals>>
I have a grain size mixture that includes oolitic sand. He is doing such a good job that I have a good amount of particulate matter in the water column now.
<<No doubt…the fish are quite the “stirrers”>>
Will this be detrimental to other livestock in anyway, gills etc.?
<<It may cause some irritation to those organisms that can’t slough it of easily (e.g. – plating Acroporids)…but for the most part it should cause no harm>>
I understand that the photosynthetic animals will not receive quite as much light until this thing works itself out, but what about fish?
<<The fish will be fine… But don’t expect this to “work out.” The goby will always find another place to dig…or at the least, gobble up mouths-full of sand and sprinkle it around the tank (crop-dusting)>>
I'm hoping this is purely aesthetic for the time being and won't hurt anything. Last time I went snorkeling the water wasn't exactly crystal clear, so I hope the fish will be okay. I guess I'm just used to my water being extremely clear with UV, carbon etc.
<<Indeed, is/will be more bother to you than most anything else in the tank. I have a 6” Barred Goby (Amblygobius phalaena) in my 375g reef display that keeps quite a bit of the fine substrate/detritus in suspension. If I had it to do over I would forgo the goby…but not because of any “harm” it has done to the system/livestock>>
Thank you,
Ben
<<Quite welcome. EricR>>