yellow prawn puberty      5/28/13
Hey everyone!
Once again thanks for all the great info and dedication!  You guys and gals are a true aquatic blessing!:)
So I've been searching all over and can't seem to find an answer to my question, hopefully you guys can offer some input. I recently purchased 2 yellow watchmen (prawn) gobies! one is significantly smaller than the other and of course the larger one is bullying the smaller one, but my hope was that one day they would pair up, the smaller one is probably a little over and inch, while the larger is about an inch an a half, the larger is a little more yellow so its probably a male( i know its not an absolute but I'm going with the odds) since I've heard the males are more likely to stay yellow. The smaller one is a little darker so presumably a female, they are currently in a 29 gallon biocube, my question is at what age/length i guess do they reach sexual maturity.
<Mmm, only a guess, but I'd say at three inches to 3.5" overall length>
 I ask because maybe if I'm right and they are the opposite sex, maybe the male hasn't accepted the female because she isn't sexually mature. (Or they will never get along and ill get rid of one).
<They will likely pair... if both persist... a 29 cube is not much space>
Also there is a tiger pistol shrimp in the tank for obvious reasons and they haven't found him when his burrow is literally right next to one of the gobies burrows…any idea how to expedite the process?
<Insert a piece of 3/4" ID PVC pipe with the tip out of the sand... nearby with part stuck under the rock>
Nothing is going right haha! Thanks in advance for your quick reply!
Regards,
Eli Ramos
<Cheers, Bob Fenner>
Re: yellow prawn puberty      5/28/13
Thanks for the quick reply as always! I will definitely try the PVC pipe, and as far as the bullying goes they don't really seek each other out so it is peaceful most of the time, aggression seems to only happen when they cross paths. But of course if I see any damage, one of them will be out!
Thanks again for your help! If I'm lucky ill get a mated pair with the pistol! Fingers crossed!
Regards,
Eli Ramos
<Do keep us informed please. BobF>

Yellow Watchman Pairing   9/23/10
I have had a Yellow Watchman Goby (YWG) for some time now. It lives with a pistol shrimp inside a PVC system. Since my YWG has begun to reach a larger size and is exhibiting some darker colors (mostly bands) I figured that I had a female. I really wanted to have a pair of YWGs but research has
yielded little results. I ended up purchasing a small (much smaller than mine) bright YWG in the hopes that they would pair off. As it so happens my new YWG has selected a hiding spot no more than 4" away (75 gallon aquarium) from my old YWG/pistol shrimp burrow. The larger YWG has shown a little aggression towards the new smaller one but nothing to harm it. I have even seen the little YWG pull up the courage to submissively approach the larger one, she will then chase him back to his rock. One thing to note is that
they are always in view of each other. I'm wondering if anyone you know has ever successfully paired YWGs together and how. Am I on the right track? Will the larger YWG ever let off the smaller one share its burrow
<Mmm, possibly. There are a few accounts of this fish, Cryptocentrus cinctus spawning/breeding and being reared... by hobbyists and commercial concerns. One of the better:
http://reefkeeping.com/issues/2005-12/ft/index.php
You'd do well to get/read Frank Hoff's (RIP) culture work/s... for food production if you intend to raise young. Please do write back if you have specific questions. Bob Fenner>

How to sex a Yellow Watchman Goby   12/22/09 Hey guys, <All right> I have been doing some research and would like to ask a question. About 3 months ago at the LFS I work we got in a what was supposed to be a blue spotted watchman goby, but what we got is a yellow watchman, Cryptocentrus cinctus. <... is the same species... Can/do change colour at times> I have been reading WWM and the web, especially an article by Amy Drehmel, http://reefkeeping.com/issues/2005-12/ft/index.php, and I am wondering if what I have is a female yellow watchman. I have included a few pictures. The first two were taken the day she was added to my tank, the last couple this week. I wish the recent pictures were better, but Ernie (along with Bert the shrimp) are shy. I have seen Bert, but this is the first I have seen Ernie in 10 weeks. I did not have time to grab a macro lens. So, my question is, do you think that Ernie is a female, and if so, what do you think the chances are that if I add a male they will pair up? And how do I make sure it is a male? Would this be a good idea? <Mmm... let's see... Don't know re the sex of this specimen. Females are said to generally be "more gray" than males, but I've seen all ranges from mostly yellow to dark gray for both apparent sexes (mating pairs). Not hard to pair this species if you have plenty of space, time for trials of mixing individuals... A good idea? An interesting one if nothing else.> For background, the tank is a 90 gallon tank, with 50 pounds live rock, a bunch of sea grass, one Firefish (Nemateleotris magnifica), one lawnmower blenny (Salarias fasciatus), one scissor tail Dartfish (Ptereleotris evides), a tiger pistol shrimp (Alpheus bellulus), and two cleaner shrimp(Lysmata amboinensis). <The Microdesmids are social animals... the first most often occurring in twos, the evides in small numbered groups> Thanks Dean <Welcome. Bob Fenner>

Re: How to sex a Yellow Watchman Goby   12/22/09 Thanks Bob, <Dean> I must confess that I had more Microdesmids; these are the two that survived QT. <Mmm, by and large I don't encourage quarantining dart gobies... actually most all Gobioids for that matter. Too much stress, likely loss vs. the small likelihood of disease transmission> I work part time at an LFS and we lost practically the whole shipment, including tank raised fish, over the course of about two weeks. I suspect something happened during shipping. <Mmm, yes> I have a 30 I was setting up to breed in. <The fish I take it> Maybe I will just establish a pair at work and bring them home. I am perfectly happy with my brown watchman - I think he is a beauty the way he is. Dean <Does look like a very nice specimen to me. BobF>

Watchman Goby Babies??-- 12/04/09 Dear Crew, <Justin> Last night as I was staring at my 29g tank in the dark with a flashlight when I came across a most interesting situation. Underneath one of my chunks of live rock, dug in a deep burrow was a large egg mass being guarded by one of the watchman gobies I have. <Neat!> What is strange to me though is the fact that one of the gobies was a Yellow Watchman, and another was labeled as a Diamond Blue Dot Watchman Goby (I have included a picture for reference). <Oh! These are likely the same species... See here: http://wetwebmedia.com/GobioidPIX/ShrimpGobiesPIX/AsterropteryxCryptocentrusCtenogobiops.htm Cryptocentrus cinctus "come" in blue and yellow varieties> After introducing the two in to the same aquarium (originally a 125g) they immediately took to one another. It was quite funny to see them, one watching out one way the other the opposite. Things started to change in the Diamond after awhile and I started to notice his/her color changing. Long story short, The diamond now looks like the Yellow Watchman, but still with his/her original markings, but I am wondering if maybe I have the possibility of some captive bred gobies on my hands. <Appears so> I wanted so bad to send a picture of the eggs (me being an avid fisherman I know what egg sacks look like..but it's always nice to throw in a reference photo to be sure), <Ah yes> but where the eggs are it's impossible to take a picture. One, there is a rather large Elegance coral in the way, and two, it's at such a sharp angle from the glass and so far back in the little cave, the camera just can't focus. I didn't want to disturb them until/unless I have to.. that and I get attacked when my hand is near =). Is there any possibility of these being fertile and me possibly getting to be a goby grandpa? <Mmm, in a manner of speaking, yes> If so, what are my best chances of getting them to survive without anything else in the tank eating them? <Actually... this batch will not likely "make it"... as you need to have on hand sufficient foodstuffs... Purchased from afar, and/or cultured in advance. ... Uhh... learn to use the search tool/indices on WWM: http://wetwebmedia.com/shrpgobrepro.htm> Or should I leave them and lets nature take its course? <Up to you... but the young will very likely not survive in the present circumstances. IF you're interested in being an earnest aquaculturist, you'll need to move the broodstock and study, develop a culture "plant" for live foods, organisms to rear them> Part of me is optimistic hoping that somehow they would be fertile and survive. The other part of me is pretty doubtful, knowing that it could just be a fluke, or perhaps the goby laid them in the chance that a passing by male would fertilize the cluster. <Mmm, good chance they are fertile... will hatch... the pair will continue to spawn> I just don't know enough about the species to know their breeding habits and behavior, if this could just be the way they breed and these will be always be just eggs, or if it's because the one of the gobies is a male, and I might have a breeding pair. I have been searching the net, but not a lot of help there. From what I can tell, a lot of people are pretty tight lipped about captive breeding their critters. <Mmmm... see the sites: MOFIB and Breeders Registry (.coms)... and the in-print works available... Much help is available that is perhaps just not easily indexed> Thanks Crew, I really appreciate it!! Sincerely, Justin Baysinger p.s. If they are fertile, and I can somehow get them to survive..anyone want a hybrid Yellow/Diamond Captive Bred Watchman Goby? Hehe <You'll see... Bob Fenner> Goby eggs Dear Crew, Sorry for the plethora of emails. I happened to notice that the burrow went all the way down to the glass bottom, and I was able to capture the eggs. I have included it here. Justin Baysinger <This be them. BobF> Forgot the picture in my previous email Sorry Crew, here is the picture. Justin <This be C. cinctus. BobF>

Watchman goby breeding. Hello, I was wondering a couple of things about Watchman Gobies (Yellow in particular and others) that I did not see in the related webpage: 1. How long do they live?<I know people who have kept these fish for about 2-3 years. I am not quite sure on how long they can live, but I know they can live at least 2-3.> I know the Neon Gobies make it a year or 2, but I think these live longer .. true?<I believe so> 2. Are Watchman Gobies successfully bred in captivity? <yes, they have been bred in captivity and are sold as captive bred fish.>Is the process the same as it is for the Neon Gobies? <Have found a couple links that should help you- http://www.advancedaquarist.com/issues/jan2003/breeder2.htm  http://gobiidae.com/ > 3. Is the sugar sized 0.2 -1.2 mm  Aragamax acceptable for them or do they have difficulty with it? This stuff packs pretty tight, doesn't it?? <Normally people keep these fish in reefs with DSB (and have sugar fine sand). I would say you should be OK> Thanks!<your welcome, IanB> Rich

Re: Watchman Gobies Ian B,   Thanks for the info. I appreciate it. I'll check out those links tonight. Rich <glad to help, IanB>

Blue-spotted Yellow Watchman Goby sexing- Cryptocentrus cinctus 5/5/03 Hello there <howdy> Thanks Anthony for the advice about the Anchor coral, I dipped it with Tech d and even though it lost a little tissue it is recovering fine <great to hear!> Local shop are going to hold my clowns until a anemone becomes available (great guys) <agreed... kudos to them :) > Now to my question how do you work out the sex of Cryptocentrus cinctus no one seems to know <not that difficult... males really do tend to me more colorful (sharper yellow and more blue spots) but more importantly... they have thicker lips (fighting/digging), a larger buccal cavity (chin pouch) and the first hard rays of the first dorsal fin are somewhat exaggerated (taller/spikier)> also what is the best sand bed depth I'm going to add one in the sump main tank is 90 gall sump holds 20 galls I thought of using 1 inch of sugar sand and about 2-3inch of  a courser marine sand on top what do you think? <never mix grain sizes under any circumstance (little benefit and will stratify without screening). You will also need 3" of sugar fine sand minimum to get good denitrification. I'd recommend 4-6" minimum for a proper DSB> the sump will also be used for fragging and growing Caulerpa and will be lit on a reverse with the main tank Thanks Tim <please read through our archives and beyond about the dangers and limitations of Caulerpa... as well as the (greater IMO) benefits of other algae like Chaetomorpha and Gracilaria for refugiums. Use the google search tool from the home page at wetwebmedia.com. Best regards, Anthony> Sexing of Cryptocentrus aurora 7/22/05 Hi, <Hello> Let me start off by saying that my wife and I currently raise Cryptocentrus cinctus (as well as several varieties of clownfish). <Neat>   We want to start raising the pink-bar goby Cryptocentrus aurora. <A beauty... know that the genus is now Amblyeleotris: http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=12694&genusname=Amblyeleotris&speciesname=aurora> We bought 4 from an online retailer with the hopes of getting at least one that looks a little different from the others as we already know that the Cryptocentrus cinctus is sexually dimorphic, <And dichromic> so we figured the Cryptocentrus aurora may be as well.  Well I can't see any obvious differences in the fish.  I'm rolling the dice and pairing them up.  We may have to see based on aggression.  Just want to know if anyone knows if there is a visual difference between the male an female of this fish? <Not as far as I know... I'd look through the few links via "Google Images" (also through fishbase.org) for others input here. Bob Fenner> Thanks,
Alan