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FAQs on Dartfish Reproduction

Related Articles: Dartfishes, CA: Family Microdesmidae, the Worm- and Dartfishes by Robert Fenner and Anthony Calfo Gobies

Related FAQs:  Dartfish 1, Dartfish 2, Dartfish Identification, Dartfish Behavior, Dartfish Compatibility, Dartfish Selection, Dartfish Systems, Dartfish Feeding, Dartfish Disease,

May not do so in the presence of others... Gymnomuraena zebra, the aptly named Zebra Moray

Pteleotris Zebra eggs JUST hatched. Help!!
Hi I've just discovered that my zebra gobies have mated and the eggs hatched tonight. They have been a mated pair for approximately 4 years. I found them by chance and I'm going crazy trying to research what to do with them! I can't find anything online and I've searched your site but I'm finding I'm a little overwhelmed with trying to find any information. I've managed to collect about 50 in a bucket with tank water and a small air pump w/air stone for circulation. Display is a RedSea Max 650, so approx 200 gallons, with 30 gallon sump, inhabitants: the zebra mated pair, clownfish mated pair, foxface, yellow watchman goby, blue tang, yellow tang, blue eyed Cardinal, female mandarin goby, Royal gramma, 3 juvenile ignitus Anthias, and 3 fire shrimp (not sure why all of that matters at the moment
but wanted to share just in case)....I know most of the hatchlings left in the display will be eaten by morning but I was hoping to get any information possible to save the others until I can make it to my LFS tomorrow morning. Photo attached. They are approx 4mm long, very long and skinny and have a very small red line behind their eyes. (Impossible to see in the photo, I know) Since the only other pair is the clownfish, I'm pretty sure these are the gobies and not the clownfish. Thank you!!
<Rearing hatchling Ptereleotris has not yet been achieved by home hobbyists, though spawning, though rare, has been reported several times. Your main problem is that the fry are very small, and although they might not actually start feeding for a day or two after hatching, they will still only be big enough to take very small live foods -- probably unicellular plankton, rotifers and so on. Certainly smaller foods than baby brine shrimp or copepods. That's typical of gobies, unfortunately. Most produce extremely small fry. I'd suggest you pop over to the Marine Breeder Forum, here:
Once there search for the Ptereleotris zebra threads, as well as the general goby threads. I'd also have you read Todd Gardner's piece over at Gobiidae.com about breeding another marine goby species, Coryphopterus personatus:
Some useful pointers there. BobF may have more to say, but I hope this gets you started! Good luck and well done, Neale.>
Re: Pteleotris Zebra eggs JUST hatched. Help!!

Yes thank you. I have already been speaking with someone over at marine breeding. I realize it will be difficult if not nearly impossible to raise them (especially not this batch since I was not prepared) but it would be fun to try. I have a lot of quarantine tanks and equipment already and am able to make my own saltwater at home so I have that in my favor. At a minimum it makes me very happy that they are happy enough in the tank to breed. Thank you for your responses!
<I concur w/ all Neale has stated; you need to quickly secure useful foods (live cultures). Likely too late for this breeding cycle, but possibly for next... Bob Fenner>

Mmm. A bit large... Clowns?

Re: Pteleotris Zebra eggs JUST hatched. Help!!      8/31/16
Yes thank you. I have already been speaking with someone over at marine breeding. I realize it will be difficult if not nearly impossible to raise them (especially not this batch since I was not prepared) but it would be fun to try. I have a lot of quarantine tanks and equipment already and am able to make my own saltwater at home so I have that in my favor. At a minimum it makes me very happy that they are happy enough in the tank to breed. Thank you for your responses!
<Welcome and good luck. Neale.>

Firefish: pairing off process from within a group? – 09/10/13
Hello Folks at WWM. I would like to have information on the process by which Firefish (nemotoloris magnifica) develop pairs from within a larger group, in which there are no previously existing pairs. I presently have in my 75 gallon reef tank, a group of 6 of them, which I have had for about 4 months. (Please know that I didn't just jump into getting them without knowing anything. I've had saltwater tanks for about 15 years. I had done research, had kept pairs at various times, and for a year or two had both a pair of orange Firefish AND a pair of purple Firefish all living under the same rock together).
<Have seen this in the wild; twice... rare>
 I like to believe that 1. leaving a nippy chasing Chromis in the tank that I really don't like, has helped to maintain cohesion in the group of Firefish;
<Likely so>
 and 2. changing from once-a-day feeding to feeding smaller amounts  a few times a day, deposited broadly in the tank, has helped to prevent territoriality or competition for resources.
<And this>
 Getting more to the point of the e-mail: Up until tonight, I have seen no aggression between the Firefish. These Firefish are almost always all 6 out in open water everywhere in the tank, and they are not at all shy (I'm guessing they might be if single rather than in a group).
<I think so too>
I have been sitting here watching the fish for about an hour, and my observation makes me want to believe it's more than simply the typical Firefish aggression that causes six to become one. This aggression is strictly between 2 of the fish. They take turns chasing and nipping each other, but in between these turns, they hoover together like buddies. They hoover together with about an inch of space between them,  not nearly touching as I have observed from past bonded pairs I've had, but nevertheless, the two of them together away from the other fish, never interacting with the other four Firefish in the tank. What should I believe about the implications of this social behavior?
<Mmm, something going on, but I don't know enough re Microdesmids, this species, to speculate...>
 Is this the way
Firefish develop into a pair from amongst a larger group, or just some interesting aggressive behavior pattern?
<Could be two males "jousting"; might well be pair-bonding twixt a pair. In the wild, adults are almost invariable found as pairs>
Thank you in advance for any information, feedback, and. or suggestions you can give to me.
<I'd keep looking about (see WWM re scientific literature searches); and asking on the various specialized petfish and scuba bb's... Thank you for sharing; and please do continue to report your observations and co-guesses.
Bob Fenner>

Sexing of Nemateleotris magnifica  12/31/12
I have been searching for a way to sex Firefish with no luck.
<Mmm, have observed Microdesmids in the wild, captivity... no distinctive sexual dimorph- or dichromat-ism>
 I found one reference that says females may be more slender.  I have had three in qt since mid November, and am hoping for a pair in my 29 gallon reef.  They are eating Spectrum pellets greedily, but the three hang out together and I have seen no evidence of one being left out of the loop.
<Ah good>
 I am hesitant to add all 3 because of how difficult one would be to remove, which is the only reason they are still in qt.  I have space in a 65 for the odd man (or girl) out.  If there is no good way to tell, how long will they take to sort this out themselves?
<Already would have>
  I would really like to get my qt ready for other additions :)  If you would like to see a picture there is one on my blog over in the Wet Web Media forums. 
Thank you!
Matt Bowers (muttley000)
<Thank you for sharing. Bob Fenner>

zebra Dartfish spawn -- 09/19/09
Hey guys! I couldn't find on your website this information- probably my searching handicap...anyway, I have three adult zebra Dartfish in my 29 gallon,
<Need more room than this>
with 15 gallon (non gravity-fed) refugium. Other inhabitants are a small shrimp goby, Fireshrimp, Japanese pistol shrimp (I think--), a small Rainford goby, a saddleback clown/green bubble anemone,
<The Anemone will ultimately eat the other fishes, likely the shrimp...>
and the typical cleanup crew. I have about 30 pounds of LR, several of which have red leafy kelp. Also, I have some good size sea shells on the tank bed to elevate/stabilize the rock.
SO!!!!!! I knew the two of the zebras had paired up awhile back, and tonight while feeding-----there's a ball of eggs on the underside of one of the shells that have been calling home!!! We're pregnant! OMG!
So- what do I do now? Move the unhatched eggs in the shell if possible to the refuge?
<Mmm... no... the parents/wormfishes are brood protectors... but you've got to have been culturing food for the young in advance...>
Once they hatch in the main tank, they might find hiding places in the kelp somewhat- but likely fish food for the voracious clown and the zebras. The tank is about 9 months old, and I feed with DT's green liquid.
The refuge is a 3 compartment tiered tank, with a sump back to the main.
:( I read about the suppliers for fry food- how long before they are likely to hatch? It would be really great to raise these babies back into the supply chain. I am about an hour south of Tropicorium- I think they breed, but have only been there one time.
<A trip to a large college library, maybe the Net/Amazon or other... for works by Frank Hoff, Matt Wittenrich... Culture gear, DIY or Aquatic Ecosystems or such... for next batches. Bob Fenner>

Helfrich's Firefish Mating -- 07/01/07 Yes I have been enjoying the hobby of keeping saltwater fish for a while now. A while back I purchased a pair of Helfrichi Firefish (Nemateleotris Helfrichi) and introduced them into a peaceful tank. I have a saddleback clown, maroon white stripe clown (both clowns share a bubble tip anemone), black ray shrimp goby and shrimp, with a Potter's Angelfish and Bartlett's Anthias. They get along great. I noticed my Helfrich's Firefish taking up residence in a cave in one of my live rocks and have become very aggressive to any fish that comes around it. They have pushed every thing away from there little corner. This is a brand new development in the past week or two. I used a light to shine in the hole it looks as if there is a batch of eggs towards the back of the whole in which one of the fish is constantly standing guard over. I know nothing of raising eggs and small fish, but would love to make a try at saving some of these beautiful fish and raising some. I would appreciate and all help you could give me. Like I said I know nothing and found it almost impossible to find anything on Firefish breeding, mating, and raising. HELP!!!!! <Congrats... is possible to raise/rear the young... the biggest challenge will be to provide adequate foodstuff/s... Please start reading here: http://www.wetwebmedia.com/drtfshreprofaqs.htm and then onto the sections below here: http://www.wetwebmedia.com/marine/maintenance/index.htm on foods, production... Bob Fenner>

How do Firefish breed ?   5/14/07 Hello guys, i have recently been given an assignment at college to explain   the life cycle of Firefish in particular Nemateleotris magnifica.  However this information seems impossible to obtain . Any help would be much  appreciated . P.S i think you guys are great especially bob  ! <Ummm, use your search tool with the term: Microdesmid reproduction BobF>

Firefish fry help  7/19/06 Hi, I hope you can help me. Today I noticed that my pair of Firefish had babies. <! Neat> They are about 1/4 of an inch and hanging out in a space between a barnacle and a rock. I have searched for information on how to rear the fry, but I have not been able to find any thing. Should I leave the fry in the main tank or remove them? <I'd remove them likely...> I also have no clue what to feed them. <They must be getting "something" from your system... you might try contacting Inland Aquatics, IPSF re their cultures for larval fishes about this size> I currently have a pair of clown fish spawning weekly in the same tank, will the Firefish continue to breed like the clowns or is this a one time thing? <Don't know... am unaware of other accounts of Microdesmid spawning in captivity. Off-hand I would have guessed these fry were actually clownfish...> Any advice you could offer would be greatly appreciated. I would love to successfully raise some Firefish!   Thank you, Sara <Time to make it on over to a library for a search: http://www.wetwebmedia.com/litsrchart.htm Try the family name, Microdesmidae, Reproduction, Larval Feeding... Bob Fenner>

Playing With Fire! (Firefishes) I have been reading up on your Firefish FAQ's. I have one Firefish who is doing well.  I couldn't find another Firefish in the whole city....  Next time I see one I plan to acquire it.  The questions... 1.  So now knowing that they should be paired... is it a "good idea" to run the risk of buying another that will not pair up?  If they don't pair up they will fight, won't they?? <Usually, one will dominate, and possibly kill the other one. This is not always the case, but it happens often enough to advise against adding another one unless the circumstances are right> Is there a way to differentiate male /females? <External sex differences are not really known, as far as I'm aware> 2.I have a 90 gallon that is 4ft long and about 2 ft deep...  is that enough surface area???  2 ft per fish right? <Yes- on paper, this should be enough room. It depends, really, on how accepting your current resident Firefish is!> 3.I have about 2" (some parts more some parts less) of live sand in the bottom with lots of hiding spots in my 90lbs of live rock.  Is this sufficient? <Sufficient to maintain these fishes-yes. But from a biological maintenance standpoint, 2 inches is sort of a "no-man's land"; too shallow for complete denitrification processes to occur, but too deep for long-term maintenance in many tanks. We always say "1/2 inch or less, or 3 inches or more", in regard to sand beds...> They do burrow in the sand don't they or will they just hide in the nooks and crevices? <In my experience, they tend to retreat to rock work as opposed to digging in sand (not that they can't, but I personally have never observed this behavior with these guys). Best to have a lot of rockwork for the fishes to establish their own territories and retreat to when they feel threatened. 4. Any problems with Firefish and coral banded shrimp, pistol shrimp, or emerald crab? <Not in my experience> My two Percula Clowns were bullying my Firefish upon introduction but have figured out that he is not food.  One tried to sample him, but my feisty Firefish bit him back... since then they have left each other alone. <Sounds quite normal, actually! Just keep an eye on everyone, and intervene if necessary should the aggression happen again> So what do I do?  Stay with the one? or get another Firefish?  Anything in particular to look for IF I am to acquire another one? Dave <Well, Dave- it's really your call here! The tank is certainly large enough to support two, the layout seems okay, but it all boils down to the fishes themselves. You do run a risk of problems if you add another one; on the other hand, lots of hobbyists have done this with a great deal of success...If you do add another one, I'd try to get one that's slightly larger than the one you have, to give him/her a little "edge" upon introduction...Once again- it all boils down to the fishes and their individual personalities...Good luck with your tank! Regards, Scott F>
Playing With Fire! (Firefishes)
Scott, Just wanted to let ya know that I did purchase 2 Firefish from the LFS. And boy, are they awesome! <They really are beautiful fishes, I agree!> They immediately started checking out their new digs, ate really well and snuggled down for the night on top of one another in a little cave in my 20gal. One is a little larger than the other and it is very obvious that he is very protective of the smaller one.  So much so as to stake out their claim in the tank and when they ventured out, the bigger one would show the little one around.  You don't see one without the other. Looks like I found quite a pair at the store. <There is certainly a possibility that it is a pair! Perhaps the size disparity will help ensure the peace in your tank. As I have mentioned a number of times here, every fish is an individual, and the fact that these two guys are getting along is really encouraging. Usually with Firefishes, the aggression starts almost immediately, so the good behavior of these two bodes well for a happy future!> I will keep an eye out if their behavior changes. What a cool hobby this is.  Also, thanks for the info on the nitrates. Maureen <Wow, Maureen- you've got me all stoked now! This sure is an awesome hobby! Good luck with these fishes- do keep me posted on their progress! Regards, Scott F>

Firefish expecting? and calcium confusion Greetings Crew!   If you could give me any information on the mating behaviors of Firefish gobies I would really appreciate it. I have had a pair I bought about 4 months ago that are always by each others side except for the past 2 days. The larger of the two has been spending most of its time in their bolt hole occasionally coming out for feeding or to swim with the smaller one in front of their favorite powerhead. It looks as healthy as ever, and I haven't noticed any aggression towards it by any other tank mates. Using my poor internet searching skills I have found some references to gobies staying in their hideaways after copulation. Wondering if this could be a signal of poor health or something to look forward to. <This lifted from fishbase.org for the family Microdesmidae: "Eggs are deposited in the burrows and presumably guarded by the parents; larvae are pelagic."> I started this tank about 7 months ago as a FOWLR (my first salt tank after a couple years in the fresh hobby) with the idea of having everything covered in coralline by now. After adding some new LR a couple of months ago I was surprised to find mushrooms and button polyps galore. Since then I have been trying to raise my calc to at least 400 with no luck. I suspect I am being overly cautious with my Kalk dosing but wanted to get an expert opinion before I start going crazy with it. I'm currently hovering in the 300-350 range. Current regimen: soon as the lights go off I add a slurry of 1/8 tsp in a cup of RO, and in the morning I do my top off using a saturated solution of 2 tsp in 1g of RO. Ph is 8.3 when the lights turn off and 8.1-8.2 in the morning when I add top off so I suspect I can double my slurry amount?? Or do I need to test ph soon after adding slurry? <Umm, I would not do either w/o measuring your alkalinity first... do you add other "supplements"? Please read here: http://www.wetwebmedia.com/calcalkmar.htm and the linked files (in blue, at top)> My coralline appears to be doing fine, but not growing past where it was when I got the rock and the slimy brown lumps that turned out to be buttons and mushrooms are bright green and appearing to be doing well but alas no new growth. Lemme know if I'm leaving out something important. <Alkalinity. See WWM re coralline algae> Specs: 55g tank, 2x 65w 8800K pc's and 2x 65w Actinism (planning on swapping the actinics with daylight bulbs.. probably 10,000K when their 8 months is up), Emperor 400(until I stop buying car parts and build a sump/fuge), Red Sea Berlin HOT w/ Rio 2500 (also will be upgraded to a Remora Pro once I get tired of cleaning and tuning it), and about 600gph of powerheads. Livestock: 1 flame angel, 1 royal Gramma, 2 Firefish gobies, 1 peppermint shrimp, 1 scarlet skunk cleaner shrimp, 8? Astrea snails, 10? blue and red hermits, 1 blue tux urchin, 1 Echinaster sp, and more Mysis and copepods than you can shake a stick at. 75 lbs of LR and a 3.5" DSB using sugar sized aragonite (will increase to 5" when everything is moved to the 75g in waiting) Parameters: sg 1.023, ph 8.3-8.1, temp 80-81, ammonia/nitrites/nitrates 0, dKH 11, <Oh, this should be fine> phosphates are less than .025, cant speak for silicates as I don't have a test but the LFS I get my water from has changed the filters in their RO unit in the past 2 months....like that means jack :) Included are a couple pics of some Cyano? that I'm hoping is part of the "new tank" thing. I feed only enough to be consumed in 1 minute (Thera A+A or Spirulina flake one day and frozen enriched Mysis or blood worms the next) daily in amounts that doesn't leave stuff to rot. <Maybe> notice the happy yellow sponges that have doubled in number since I got the rock.. Cyano pic is below I have been vacuuming this stuff out, and although it comes back weaker every week it still comes back. Thanks again, y'all rock! Now go out and have fun, its Friday! Emerson <Do take a read through the Cyanobacteria control articles, FAQs posted on WWM as well. Bob Fenner>

Honeymooners? Nemateleotris Magnifica acting strangely 07/19/03 Hello there crew ! <Hi Luis, PF here today> Great work you're developing here...! We have this FOWLR 65 Gal. display tank and the actual population comprehends 1 Zebrasoma flavescens, 1 Percula, 1 Yellow tale blue damsel, 2 Nemateleotris Magnifica. A week or so ago we began to realize only 1 at the time of the Magnifica went outside their usual cave to eat and take a look around like they both used to. Could this mean they've spawned. Is it possible they're setting up "guard" to the "nest" one at the time? If so, can we do anything to help preserve the future bunch to survive? Thank you. Luis Santos (Portugal) <It sounds like a spawning even to me. Very cool! Unfortunately, I checked Google and the breeders registry (http://www.breeders-registry.gen.ca.us) and I couldn't find any information on breeding Nemateleotris Magnifica. My best advice would be to get your hands on Martin Moe's Breeding the Orchid Dottyback, lots and lots of good advice on breeding fish in there. I think though, the odds are that your hatchlings are destined to become part of your tank's planktonic mass. Mr. Moe's book includes advice on removing the larvae, feeding, etc and I really think it's your best bet. Good luck and keep us informed, PF>

From the Frying Pan and.. Firefish Fry.. >Hey there howdy, Hey there yourself. >I picked up a pair of Firefish recently (Nemateleotris magnifica), they're spawning right now,, I'd really like to have a crack at raising the fry. >>Alright.   >I've raised Gold-Stripe Maroon clowns successfully twice (times unsuccessful, don't ask) so I have a blacked-out tank etc. ready to go.  I can't find anything useful in the breeders' registry and am wondering about the incubation period and feeding of the fry.  Maybe you can point me in the right direction of someone who has done this successfully?  As always, great job. Best, Justin >>Hhmm.. well, assuming you've already Googled, I'd try hitting up some of the reefing boards and forums.  I'd also try contacting the folks who are providing animals like captive bred Dottybacks and gobies as well (OSI is a big one, if I recollect).  I would expect you'd need something akin to a proper fish room, but if these fish are already breeding, I'm fairly certain they'll do it again.  Marina

Mated Pairs Howdy, <Hi there> Do any of you know any on-line retailers who sale mated pairs of vert.s and inverts? Thanks, Steven <Most all of them do... principally clownfish species, some shrimps... If it's something "important" you can even put in requests... that reach all the way back to collectors, breeders.  Which part of the world are you in? For ease of matching close-by suppliers. And what sorts of organisms are you looking for? Bob Fenner>
Re: Mated Pairs
wow, thanks for the fast reply Bob. I am located in the southeast, US. I was kind of interested in a mated pair of Coral Banded Shrimp (Stenopus Hispidus) and a mated pair of Fire Fish (Nemateleotris Magnifica). I would actually like more of the latter, say around 4 or 5 but it may not be a good idea. I would think a truly mated pair would be allot safer. I have a 100g by the way. Again, thanks for the quick reply. Steven <Don't know about the Dartfishes (the way they're collected I don't think the pairs are kept separate), but the CBS are do-able. Have your supplier/LFS contact Quality Marine or Sea Dwelling Creatures in Los Angeles. Bob Fenner>

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