Pairing Neon gobies--Elacatinus oceans

Someone asked me about pairing neon gobies. He bought 5 and they are shredding each others' fins in a 55 gallon QT tank.
My first thought was that the fish are all males, and he should buy more and try again. Then I read some stuff about pairing them, and it seems that when there are just a few, they try each other out until there is only a pair left.  Indeed recently with my Elacatinus evelynae, they were all so aggressive, I despaired of getting a pair. Once I split them up, however, I found first one pair, and then another.
 
Also, I think in the case of such small fish, a smaller QT might be in order.  Just my opinion.  I currently have about 11 in a 15 gallon tank with 5 clarkii clownfish, and about 60 in another 15 gallon tank, where they grew up from babies.  Anyone want to buy some?  Thus crowded, they all get along well.
 
Here's the hypothesis: with just a few gobies in a large tank, the urge to mate is high, but they have to find, from the remaining fish, a suitable mate.  Fighting is the way to find one, and protect it from the others who also want to mate. They are trying to rid themselves of the competition.
In a smaller tank with lots of gobies, mating is impossible, and growth and survival is the top goal. 
 
I really don't know, but I get the feeling that these fish are not hermaphrodites.  I think they have a sexuality determined at birth.  I can tell males from females only by behavior in relation to their mates.  Before they have a mate, it it impossible.
 
I hope this helps, but I am interested in what the rest of you have to say about this matter.  Please chime in.
 
 

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As a suggestion for pairing them, if you don't have a few 10 gallon tanks, I would suggest you put 2 in a breeder basket, and see if they get along. Actually, I haven't tried this yet, but I really should, if I ever want to sell all the gobies....
 
You can tell if they like one another by whether or not they try to kill one another, but more often than not, they will show their love by forming a T with their bodies and quivering like the clownfish do.  My elacatinus stand parallel, head to tail,  and slap each other in the face with their tails.  It's so cute.
 
Basically, if they hang around together and don't chase and run, you have a pair.

check out Kathy's Clowns, llc website:
http://kathysclowns.com
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(Wholesale to the trade.)

This is interesting. When I was working with these I bought 6 from a diver in the keys and quarantined in a 10gal. One died for no apparent reason. Very little if any fighting but I fed very well in there. Because I couldn't make out pairs at the end of quarantine, I just moved all 5 into a 37 gallon tank.

One immediately jumped after the move. The remaining 4 lived together in that tank for quite some time. A dominant pair emerged and periodically chased the two subordinate fish but no shredded fins or anything ever came of it. The dominant pair would spawn but the other two never paired and seemed to not grow from that point, though they were in good physical condition. The dominant pair nealy doubled in size from the time of purchase to the time they were all sold. They lived together for about a year like that.

I once had a similar experience.  In a gang of 5 in a QT, one pair started spawning.  I removed 2 to another tank, randomly, and the other lone fish to another tank. The 2 subordinate fish were soon in love and spawning.  That was oceanops, and I had a similar luck in pairing the evelynae most recently, although there was more aggression when all 5 were together, and nobody spawned.  Just getting two compatibles together in a tank by themselves seemed to work.

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

I once had a similar experience.  In a gang of 5 in a QT, one pair started spawning.  I removed 2 to another tank, randomly, and the other lone fish to another tank. The 2 subordinate fish were soon in love and spawning.  That was oceanops, and I had a similar luck in pairing the evelynae most recently, although there was more aggression when all 5 were together, and nobody spawned.  Just getting two compatibles together in a tank by themselves seemed to work.

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

Joe, what's your trick for selling gobies? 

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

Hi guys, I was the one with the original question to Kathy about pairing these. (Kathy, thanks for all the info and getting everyone in on the answer!)  So I started with 4 fish in a 55 gallon quarantine tank with lots of 3\4" PVC around the bottom.  This was a disaster as all 4 fish constantly tried to kill one another.  Now I have all 4 separated into fish baskets from Florida Aqua Farms (basically breeder nets) hanging inside the 55 gallon tank.  I have been trying to pair them in these baskets with no luck so far.  I even tried letting two at a time out into the 55 gallon and still all I got was battle.  It is possible that all 4 of these are the same sex.  The largest one has developed a swollen abdomen and looks to be full of eggs.  The other 3 are half "her" size and appear to be very small (juvenile) fish.  Like Kathy said though, it is possible that the sexes are determined at birth (or very early in development) and they are all the same sex... My thinking is I'll keep trying for a week or two and then see if I can buy a few more fish. 

Jeremy, I'll also try to get a pair together from my immense stockpile, and see if I can help you out.

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

Sweet! I would be interested in buying a pair or two from you if you can ship!

That could be it. If the only female is larger than the rest, she is not crazy about those boys, and the boys are all fighting over her.
 
So far my pairing attempts this past weekend are 3 and 3--3 attempts, and 3 apparant pairs. But  I have an extraordinary number of fish to work with.  Email me, Jeremy.

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

You are probably right.  Big momma wants a man fish, not all these little boy fish I keep throwing at her...lol.
I sent you an email about the evelynae gobies.

Spoke too soon.  One pair did not work out.  Smaller one killed by larger one...

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

I bought 3 Oceanops for my first round with these guys. I put them in a 10 gal with a pair of ocellaris. Within 2 days i had a pair and in 3 days the odd one out came up missing. It took them 2 weeks to start spawning. They were a consistent Spawning pair until my female died. So I went down to the LFS and bought another one . It was a little smaller than the male I have. I put them together and they were fine. I never seen any fighting, and 2 weeks later they were Spawning. I am on my 3rd spawn with this pair now. If the sexes are determined at birth I have been very lucky Now if I could just get them past day 7.

I think my perseverance paid off!  After several failed attempts I may have a pair.
 
 

Today this is all that was going on in there (see video).  Could this be spawning behavior so soon? The one in the PVC looks like she is trying to coax the other one in there.  "She" shimmies every time the small one comes near the pipe and only comes out to eat. Until today this fish never went into the PVC.