Captive Diet for Eviota Goby – 04/30/07
I would like to thank Lynn for her reply on my question regarding the compatibility of Eviota gobies and emerald crabs.
<Thank you for the feedback, I will CC to her.>
I decided not to take any chances and evicted my emerald crab to my 5 gallon prison as it were.
<Cool.>
Now I would like to inquire as to some information around the feeding of Neon Eviota Gobies.
<Okay.>
I've read that live rock can provide a source of food for these critters,
<Very true, microfauna/crustaceans are a natural and nutritious food source not only for this fish but many in captive aquaria. Fishless refugiums can help to accomplish this goal.>
how large a part of the diet does it make up?
<In the wild THIS is the diet of many gobies...they feed on microfauna and zooplankton for the most part.>
would about 4-6 kilograms of rock be able to produce enough food to sustain them solely on that?
<Unfortunately no.>
taking into account my hermits and cleaner shrimp as well of course.
<Yes...>
What is the ideal food for these little critters?
<I would supplement with fair such as Mysid, Mysis and krill. Chopped up bivalve meat would not be a bad either. For dry food try spectrum or ocean nutrition.  Also consider supplements like Selcon or Zoecon.>
I've read that other than the live rock they also feed on zoo plankton and fine chopped meaty items, shrimp, fish, clams etc.,
<Guess I should have read that before typing my above response, hehe.>
and the man at the LFS who sold them to me says he just dumps in some regular food (flakes and stuff like that).
<They aren't really picky once they adjust to captive fair, but I find variety to be very important.>
So I would really appreciate a response on this on how to provide the best diet and feeding for these little guys.
<You are on the right track my friend.>
Best regards, Mark Forsling
<To you as well, Adam J.>

Goby Diet, Mix it Up!  4/26/07
Hey WWM Crew,
<What's up Joe?>
My Clown Goby looks awfully skinny.
<Uh-oh.>
I never really noticed it before, until   I really took a good look at him. You can almost see through him, and notice his  bones and organs.
<Mmmm...not good, he needs some meat on his bones!>
He isn't really plump as other clown gobies look in person and  in pictures. I feed him every single day, and I watch him eat.
<What is he eating though and how much?>
The only other  fish in the tank is the Flame Angel, and he favors the Spirulina shrimp much  more than the Mysid. The goby loves the Mysid, usually eating as much as he can.
<Try mixing it up a little. Variety is important with diet, go for some mysis (PE is a personal favorite of mine), krill or even some finely chopped mussel or bivalve meat. Also consider a vitamin/fatty-acid supplement like Selcon or Zoecon.>
He doesn't really fear the Angel, he will sometimes attempt to out compete him  and get as much as he can from the cube and take it to the top of his power  head. What I do when I feed is place the cube on the surface, holding it with my  fingers, and let a certain amount of pieces break off, and save the rest.  Otherwise I would have a lot of uneaten food and excess nitrates. Is there a way  to beef him up? Or is it normal appearance?
<See above....remember "VARIETY.">
From,
Joe
<Adam J.>

Blue Cheek Goby - Not Eating ? 8/2/05
Hi WWM Crew,
<Paul>
I bought a blue cheek goby yesterday and it has hidden behind one rock and not come out once...
<Shy fish>
I bought it to eat the algae off the top of the sand bed as we have plenty to eat but as yet it hasn't come out.
<May not for a few days>
Water is fine, acclimatized it well (although I'm sure all fish stress when being transported). It's also in the tank with non-aggressive fish..
I can occasionally see the goby under this one rock however it never seems to come out, even when we feed Mysis.
Can you give me an indication of whether this is normal and if I am ever
actually going to see this fish in my display tank?
Many thanks,
Paul
<Patience my friend. Bob Fenner>

Re: Blue Cheek Goby - Not Eating ? 8/3/05
Hi Bob,
<Paul>
Many thanks for your response, 100% reliable as always, much appreciated.
<Welcome>
I can report back that the Goby has started to come out, only in an afternoon strangely and goes under its rock at about 6pm every day (lights
go off at 8:30pm though!)  Strange?
<As in "unusual?" No.>
Goby has started to sift through the sand but only at one side of the tank, I suspect I need to get him eating brine / Mysis but he goes under his rock
and won't come out to eat,  is this just a patience thing also ?
<Ah, yes. BobF>
Many thanks
Paul

Starving Goby 7/27/05 7/28/05
G'day all, Thank you for all the information you've provided to me and all fellow hobbyists. Well, just wanted to ask a couple of questions on my marine aquarium, which has been running for 7 months.  I have a 48 X 18 X 18 inch tank, (240L approx):
Approx 40kg live rock (from Australia, as I live there),
3 inch aragonite + 1.5 inch coral sand, substrate (on top of undergravel filter plate, 4 X powerheads, ranging from 1200lph-2300lph, each with rotating deflector, Prizm (RedSea) hang on skimmer, 1 X internal 500lph filter (filled with carbon),3 X 30W fluoros, (2 Hagen PowerGlo, and one actinic blue).
<All sounds good!>
Livestock includes:
1 percula clown,
1 Fijian damsel (blue with yellow underside + fins),
1 sergeant major,
1 regal tang,
1 royal Dottyback,
1 clown/coral/lemon goby.
<This is a bit of a volatile mix.  The damsels and Dottyback all can be quite aggressive, especially toward the docile clown and goby.  Also, this tank is quite small for any tang.>
1 brain coral, 1 Heliofungia coral (I realize the light isn't really sufficient), 2 leather corals, (1 toadstool type, and one polyp type).  <Your light is probably adequate for all of these animals.  Heliofungia has a very poor survival record that has nothing to do with light.  It just doesn't survive well in aquaria.  Gut studies of wild specimens suggests that they feed on microscopic plankton that is absent from our systems.>
Just want to ask your opinions on my tank, any issues with stock, equipment etc, as I am pretty much a newbie. I've had one death occur with a Rusty angelfish, who died for no particular reason. I had it for a few months, in perfect condition, but one morning I found it dead (with no wounds) on the substrate, whereas the night before it was showing normal conditions/behaviour. <Such mysterious deaths are always frustrating.>
Also, the goby mentioned above, was not eating since I purchased it, 1-2 months ago. However, it has started eating mysis shrimp, but only one or two pieces during each feeding session. After that it either stops eating, or it will swallow a piece and then spit it out. Any tips on saving the fella, cos he's become extremely skinny.  Thanks always, Alex <Mysis is usually pretty irresistible.  I would try smaller bits of mysis and perhaps live/frozen brine shrimp.  You could also experiment with very small bits of squid, fish meat, etc.  I would continue to experiment until you find something that tickles his fancy and then slowly wean in more convenient foods.  Good luck! AdamC.>

Finicky Rainfordi Goby...
Sorry, I think that my computer just sent my
email when I tried to break it up into two paragraphs;
here is the second part.
<Oops..>
The Rainford goby has now been in a 10 gallon quarantine tank for six days and will not eat.  I have tried frozen brine and Mysis shrimp, formula two
frozen and flakes, even Angel Formula, and it won't touch anything.  I also put a Tupperware of sand into the quarantine tank to see if it would sift that.  The live rock from the main tank are too big to fit in the quarantine tank.  Is there anything else I can do for the fish?  I was thinking of biting the bullet, dipping it, and adding it into the main tank, which (and back to the lack of foresight in my suggestion) does not yet have a refugium as I am still saving money for a small CPR hang on model.  Please help, and again, thanks for your time. Rob
<Well, Rob- I'd be inclined to add some pieces of live rock from your display or another established system into the quarantine tank for him to forage one. In addition, you could purchase some life amphipods from a number of e-tailers (Indo Pacific Sea Farms comes to mind) and feed these live foods to get him going. Don't give up just yet, and try to defer releasing the fish into the display tank until he is finished with the quarantine period. Don't give up! Regards, Scott F.>

Gobies refuse to eat
Hi,
<Hello>
I got 2 gobies, a Randall's Prawn Goby and a Yellow Prawn Goby, that don't eat. I have both of them for almost a month. I tried to feed them but they are not eating and they are getting skinnier as the days go by.
I try to feed them with minced shrimps, minced fish, Mysis shrimps, flakes, and small pellets but they just not eat (or I don’t see they eat), even if I place the food in front of them.
The Yellow Prawn Goby always hides in an inaccessible cave. How can I lure him out at feed time?
<Add a Prawn...>
Is there anything that I can give them so that they would eat? I really hate to see them slowly waste away by starvation.
<I would try some live food, soaked in an appetite enhancer, vitamin mix (e.g. Selcon) pronto>
By the way, do those fishes feed at night, when the lights are out?
<Whenever their symbiotic Alpheids are out. Bob Fenner>
Thanks for you help!
Regards,
Minh

The Goby and The Mystery Star!
Hello all!
<Hi there! Scott F. here today!>
I wrote a while ago about a golden headed goby that wasn't eating, and soon after that email (in an act of desperation, and in hopes of getting to keep the little guy) I bought some dried blood worms and whole frozen mysids.  He loves them, he darts out of his hole every time I open the fridge to get out the mysids or pick up the bright red can of worms, he has filled out quite a bit since he started eating the things I put in, but he's still too skinny to stop worrying, will he fill out completely on this diet or is there something else I should start offering him that will fatten him up faster?
<Well, I think frozen Mysis are one of the best all-around foods for many marine fishes. You can "enrich" the Mysis with additives, such as Selcon, which provides highly unsaturated fatty acids, or VitaChem, which (as it's name implies) provides extra vitamins. There is also brand of frozen Mysis by Piscine Energetics, that is already enriched. Other foods to try would be foods like Hikari "Mega Marine Angel", which does have some marine worms as part of it's formula, and is actually "extruded" during the manufacturing process so that it resembles worms. It's very high in vitamin content, and many fishes like it, despite its "Angel" title. >
I was told to put him in a friend of mines more established tank, but I'm really fond of this character, with him eating like the other fish will he be ok now or should I still pass him on?
<Well, I hate to give up on a fish, myself...Since he seems to be coming around now, I'd stand by this little guy and watch him begin to thrive!>
I have one last question.  I have a starfish that was labeled as a "sand shifting star"  but my problem is that all the pictures I've seen of the sand shifting stars aren't pictures that look much like my guy, and unlike the descriptions that say they can't climb, he can.  He has suckers and although he doesn't seem too interested in climbing, from time to time he'll camp out at the water line.  I looked through one of your pages of starfish identification and he wasn't there either, he's cream colored with darker brown stripes, but he doesn't have those longer spines edging his rays that the sandsifting stars in the pictures have, his are very short.  Do you know of any sites that have pretty complete lists of the species that are sold in pet stores?
<Well, based on your description, it sounds like this might possibly be a brittle star (genus Ophioderma)...I have one that is cream colored with dark bands...On the other hand, if it does not have other characteristics of a brittle star, it might be any one of dozens of possible species. I'm not aware of a web site, off hand, that specializes in Echinoderms, but you could certainly do a search on one of the larger search engines on the 'net, to see what's out there. You also will definitely want to order a copy of Bob, Anthony, and Steve's upcoming book, "Reef Invertebrates", due out in March!>
I was just curious, I didn't know if this guy is maybe different from the sand shifting species altogether and maybe he'd take a liking to a special diet instead of the leftovers he's getting now.  Thanks for all your help!                                    Sincerely, Rachael
<Well, Rachel- I think it's great that you're hanging in there with the goby. Your tenacity has paid off for both the fish and you! And I love the fact that you're concerned enough to be researching the dietary requirements of your animals! What a great habit to get into! Keep up the good work! Regards, Scott F>

Hungry Goby?
I have a yellow headed sleeper Gobi (Valenciennea strigata) and he is acting fine and sifting like crazy, but he is loosing a lot of weight fast. I had this problem with a Kole tang about 4 months ago and 4 year old blue damsel. However, my mandarin, cleaner shrimp and Mustard Tang are fine and seem to be thriving.
Tank 55 gal
Wet dry
Skimmer
70 Lb LR
Can't seem to figure this thing out. Primary source of food is Mysis and whatever they can scavenge. Mysis is feed every 2-3 days and water parameters are right on. Perhaps a parasite?
Peter
<Well, Peter- internal parasites are a definite possibility. Many fishes do harbor these organisms, and the problems can manifest in your tank. These fishes tend to waste away in captivity if high protein foods are not eaten regularly. My best suggestion here would be to see that food is placed where he can easily get to it (like on the bottom of the tank). This will help assure that he gets his fair share. In all likelihood, there is not enough infaunal life in the sand to sustain him, so keep the food coming his way. Hopefully, this should fatten him up a bit. Good luck! Regards, Scott F>

Starving Goby (1/27/04)
  hey guys- I have a watchmen goby who appears to be starving to death. <signs & symptoms?> the only food I can offer is staple flake enriched w/ Selcon and a refugium (newly set up). <Why not frozen foods?> I read on your articles advising of nutritional deficiency and was wondering if there is anything I can do to nurse sally back to health. thanks again Justin Barstow's <A new refugium is not likely to be putting out anything useful yet. Some of these gobies will take flake/pellet foods. Others will not. Are there competitors in the tank that eat everything before it gets down to the goby? I'd suggest target feeding with frozen Mysis shrimp or other frozen marine foods. The Selcon is a good idea too. Hope this helps, Steve Allen.>

Starvin' Marvin the Bluebanded Goby
>Hi all,
>>Hi.
I have a Valenciennea strigata that has been in QT for a little over a month and it seems to be losing a lot of its girth. It has been eating the omega one flake I have been feeding it, it seems to love this stuff, really tears it up. I am wondering if that is all it is doing, with the amount of food (flake) it is consuming it should not be this skinny. Does this fish need another type of food, I thought omega one had sufficient protein for this fish, or does it just sift it thru its gills and break into tiny little pieces w/o digesting it. I had had exceptional luck with this fish accepting the flake food so i am assuming it would easily accept other types. Should I try something else to fatten it up, and if so what do you recommend?
>>Check out this site: http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=6575&genusname=Valenciennea&speciesname=strigata
It outlines part of what this fish feeds on.  Another issue, unfortunately one that cannot be solved if such is the case, is possible exposure to cyanide.  This poison destroys the gut in such a way that any food eaten cannot be utilized.  I do hope it's more a matter of providing a better/different variety of foods that better mimic its natural diet, rather than cyanide exposure.  Best of luck to you, Marina
>Thanks, Ryan

Goby Grub! (Feeding Question)
Sorry to bother you, but I have a question with which I'm having trouble getting an answer. I have a 40 reef tank, a couple small corals, probably 30 lbs live rock, two Clownfish, a Flame Angel, a couple of snails, and two sand sifting star fish. Also, two cleaner shrimp, and probably hundreds of baby shrimp in the rock. I have recently added a diamond back goby. Just like in the picture on your web site, however you use the scientific name.  Basically he is white with orange diamond shaped spots up and down his back.
My question is about food for the goby. What specifically will he eat, and how often should I feed him. I am concerned about him running out of substrate and starving. Any information you could provide will be appreciated.--Thanks--Bill
<Well, Bill- I guess I'm not 100% certain which goby you are referring to, so my answer will have to be kind of general. A picture would help! Most of the gobies that seem to fall into the category that you are describing can proof difficult to feed. They require copious amounts of small crustaceans, such as Mysis or amphipods, as well as other life forms typically found in a healthy, established sand bed. I'd provide frozen Mysis, enriched brine shrimp, and other fine "meaty" foods of marine origin. An established, productive refugium would be a big help, and could assist in providing your fish a continuous supply of the necessary foods. Either way, keep him well fed (like twice daily), and observe him carefully to assure that he stays in good health! Good luck! Regards, Scott F>

Goby On An Eating Binge?
Hi All,
<Scott F. here today>
Thanks for your site! You helped me many times save many lives by reading the resources along the wonderful books. I've looked but didn't find help with this one. I have a 240 gal. that's been up for one yr. I have many fish that eat Nori, (tangs, angles). I noticed my diamond goby looking pregnant last night. I've had this fish for nine months. This goby is the only sand sifter in the tank. He always eats well, from both the sand and frozen Mysis, krill and live brine. He has tripled his size and has a thick body. I fear he has eaten a rubber band that I noticed was missing. Is there any I can do for my little guy? Is there any hope for him? Tonight he's not sifting very much, although he had a lot of live brine. He is out and about, but swimming a little less than normal. Any help would be great.
Thanks, Quinn
<Well, Quinn it's hard to say what's up with this guy. I'm willing to bet that he didn't ingest a rubber band, but it's certainly possible. However, I certainly would not discount this. A good sign is that the fish was eating. If he has some sort of intestinal blockage, there may be nothing that you can do, unfortunately. I suppose the best thing that you can do at this point is to watch the fish carefully, and see if he takes on food. It may simply be that he ate a lot of food or ingested other matter
that lead to his swollen appearance. Hopefully, this will have just been the result of a "binge", and he'll pull through fine. Keep your fingers crossed. Regards, Scott F.>

Blue cheeked goby needs bulking up
Dear Bob,
<Michael>
I have written you before, and thanks for the response. I have a new question. I was at a pet store looking at a blue cheeked goby, aka yellow headed sleeper goby. When the clerk found out that I had interest in the fish, she pleaded with me to take it, she even gave it to me for free.
<!>
Apparently they had requested a different fish, but were given this one as a replacement, and they were not prepared to keep this fish.  Since it was such a fussy eater and they did not have the proper system, and a tank for itself, they couldn't feed it properly, and it was slowly starving. I took it and promised I would try my best to recuperate this poor fish. I have live sand which it is sifting, and I read a suggestion of mixing food (Mysis, brine, or chopped shrimps) into the sand, which I have been trying. I am also, as soon as time or whether permits (at the moment I am in the middle of the nor'easter in the northeast US, going to get live rock for my tank.
<Good>
Do you have any other suggestions, tips, and/or tricks I can use to get this fish healthy again?
Thanks, Mike
<Do soak whatever small, meaty foods (whole or chopped) in Selcon or such for a good ten, fifteen minutes and when you have time, use a plastic "turkey baster" to carefully squirt some of this (mixed in water) toward the area where this fish is sifting. Bob Fenner>

Foods for gobies
I have a LOT of live rock in the tank; probably 35 - 40% of the tank volume. However, the tank is only about three months old, so there are a
fair amount of copepods, but not a lot of other misc. life in the sand.
Unfortunately, I do not have a tank that could provide better substrate as I have recently overhauled all of my other aquariums. Am I just out of luck?
>>
Hmmm, maybe not. How about good relations with a livestock fish store? One that cures their own live rock. Make a deal with them to collect the "muck" etc. on the bottom of their sumps... and chop up those bristle worms et al. and see if your gobies will accept this material.... freshly prepared. You can store unused matter in the frig. till it's needed.
Bob Fenner

Feeding my Goby
Dear Bob,
Thanks for the quick answer regarding stocking. The Hawaiian Yellow Tang will be next.
<Ah, a good choice>
Following your writings regarding Valenciennes puellaris, I am concerned that my beautiful 4 inch Goby may not be getting enough to eat. No visual problem, he seems fat and happy, digging through the substrate several time a day and occasionally laboriously paddling to the top of the wall and diving back down. He has tunnels under the rock work to hide/sleep in.
<Sounds good... it he getting thin?>
1/4 of the substrate is 2 inches of aragonite gravel and 3/4 is undulating average 3 inches deep fine aragonite (1/2 put in "live") tank is 7 months of age. While he has been going through the sand a lot I worry 'cause I don't see how he gets any nourishment from it. I tried dropping in finely chopped raw shrimp and also dry shrimp pellets but the crabs, shrimp, and other fishes grab them.
<Yes... perhaps some other food source would provide more continuous supply... my fave choice would be/is a refugium type sump... with live sand, rock, Caulerpa... and continuous or alternating light/dark (with your main system)... >
Now each week after cleaning the glass I am using long forceps to bury dry shrimp dry krill pellets about 1/2" under the sand. Will this be enough "fauna" to sustain him. Your advice, as always, would be appreciated. 
Howard
<The only "answer" is to observe your livestock... if this Goby is getting thin, you will definitely be able to see it. Bob Fenner>

Re: Feeding my Goby
Dear Bob,
I don't understand how the refugium will provide food for the Gobioid but I already have on under construction.
<It will be a "breeding/production ground" for all sorts of crustaceans, worms and other creatures that will make their way (through the overflow) to the main system, and provide important molecules that will improve "water quality"... all in all benefiting your Goby>
I will be using a 3 gallon plexi box located above the sump with a 100 gph line tapped off the filter circuit and an overflow back into the sump. It replaces the blue ball box that I used before adding live rock and getting everything in balance (shut it down after reading some advice to others on wetweb.. 
<Ah, so gratifying to read>
I will plant it with Caulerpa attached to live rock junks (I'm cultivating some in a spare tank, both grape and blade). I will light it 24 hours a day with a spare 20 watt aquarium fixture left over from fresh water days.
<Very good...>
Any suggestions would be appreciated. Is this enough light for a 10 inch deep refugium? What "color" light tube should I use? Many colors are
available for this All Glass fixture.
<Yes, enough light, circulation... a good plan overall... look for a full spectrum (5K temp. or higher) lamp... a Vita-lite would be ideal. Bob Fenner>

Citron Clown Goby ?
Hi Bob, would greatly appreciate some advice on a Citron Clown Goby I purchased from FFE two weeks ago. He doesn't eat much and seems pretty thin to me. All the pics I've seem of these guys show they are more plump than my little guy. He swims out and grabs a couple of pieces of whatever I'm feeding, brine shrimp, other chopped up stuff (soaked in Zoe and Zoecon) and that's it. He seems alert and perches on the corals (just softies). His tankmates are two false Percs, a yellow tail and humbug damsel, two cleaner shrimps, and a sally lightfoot. But no one bothers the little guy. I read in your facts that sometimes you won't see them eat, they eat plankton from the substrate at night. Will his appetite pick up as time goes on? Did I just get an anorexic fish?
<Hopefully will improve in "plumpness"... as other behavior sounds good. I'd keep trying different small, meaty foods (do you culture anything like in a refugium?) and not worry.>
Thanks so much for helping me, and your contribution to the hobby.
<You are welcome my friend. Bob Fenner>
Phyllis
SC

Citron Gobies et al.
Good morning, Dr. Fenner,
Long time since the last time we chatted, uh? I hope all is well.
I decided to drop this quick in view of late opinions I have heard about Citron Gobies (Gobiodon citrinus) and their kin (Gobiodon histrio and others) regarding their food choices. Some aquarists are reporting that their little guys are eating SPS polyps and I was under the impression (perhaps mistaken) that they would only do this at times of mating.
Could you provide more info on these guys eating habits and preferred choices? The tank I am planning does include these little guys as well as an emphasis on SPS corals.
<The genus Gobio does live in very close association (the only place I've ever seen them in the wild) with Acropora species (ones that look like "table tops"... I wouldn't be too surprised to find that they might nip, eat them, other SPS polyps... Ones in captivity I've seen eat most all small meaty foods, live and trained to take dead. Just must be small in size (to accommodate tiny mouths) and moving. Please read here: http://www.wetwebmedia.com/gobies.htm
Bob Fenner>
Thank you and have a great day!
Mary.

Eel Goby Not Eating <Actually family Bythitidae, Order Ophidiiformes... What's in a (common) name? RMF>
Any ideas on how to get my yellow eel goby (Brotulina fusca) to eat. Tried brine, flake, etc. and nothing seems to interest this fish?????? 
< Anthony Calfo and Steven Pro in for Bob: a moderately hardy fish... try frozen mysids, Pacifica plankton for starters. Collect copious amounts of natural plankton (amphipods) fro a filter pad on a system with live rock like a reef (LFS, Friend, society member). Last resort... Selcon soaked live brine shrimp. Best of luck to you.>

Rainford Gobies
hello
I'm Huig from Belgium. 
<Cheers my friend from far away! Anthony Calfo in your service>
you'll probably get a lot of emails and I hope you will find the time to read and
answer mine. I'm very interested in biotope aquarium, but it's hard to find information on this. I'd like to combine species from the same geographical region which require the same care. if possible species that live next to each other and do not occupy the same niche. and if possible species that have a chance of being reproduced. some info found is contradictory. one of my favorite species is Amblygobius rainfordi. 
<yes... a very beautiful fish!>
almost everywhere I read it lives on sandy and muddy substrate but in Korallenriff aquarium from Svein Fossa it is told that they occur over stony substrates and pick on algae and crustaceans. as I have a 350 l aquarium decorated with live rock and live sand. I previously stayed away from them but with this new (maybe false) info I'd like to add them to my tank. as I read in one of your articles you observed them in the wild. I hope you can tell me about their preferred
zones in nature. thanks
<Rainford's goby is notorious for being very difficult to keep for long in captivity and this is largely because of its seemingly strict dietary requirements. The nature of its substrate is truly secondary to this dietary need as they have been observed on both hard and soft substrates as you have noted. For many years the common denominator to their success in captivity has been a constant supply of hair algae (Derbesia or like species have been "employed" perhaps inferior to turf algae) Since such algae is generally considered to be unsightly and a nuisance... many Rainford gobies are not kept healthy for very long. Turf algae species are really perhaps more appropriate and their recent popularity in algal scrubbers and subsequent methods for cultivating a continuous supply may help keep species such as the Rainford goby. Ironically, it may not be the algae at all that they need to feed upon but rather the zooplankton attracted to the dense mats of algae. Regardless... are you really prepared to turn your 350l display into a field of algae for this fish? Most people would not be willing, but you have said that you are interested in a biotope display. If so, I hope I have reassured you that you need not worry so much about the nature of the substrate and rather to focus on cultivating turf algae and incidentals within it for keeping the magnificent Rainford goby. Best regards, Anthony>