Blue Spot Jawfish - 3rd time the charm?

So far I have not observed a single burrow swap with these two, also no real aggression aside from a warning if one comes too close to the others burrow during feeding.

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They also got well through the recent heat wave thanks to an improvised fan chiller. Despite the garage hitting smoldering 34°C their tank stayed at 25°C.
I have way too many tanks to get each of them a recirculation chiller and based on my experience this past week I'm gonna equip all my tanks with forced air evaporation chillers. Given that evaporating 1 gal. of water extracts around 8,000 BTU, this can actually be quite effective.
 
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I'm happy to see that you have your BSJ tank up again. Love the vids! They have so much personality. It's amazing to me, as I watch them dart out and feed, how they can go in full speed reverse back into their hole, in strong current, and nearly every time, make the entry back in perfectly. Once in a while, if they get too far away, they miss, but not that often!
 
I'm happy to see that you have your BSJ tank up again. Love the vids! They have so much personality. It's amazing to me, as I watch them dart out and feed, how they can go in full speed reverse back into their hole, in strong current, and nearly every time, make the entry back in perfectly. Once in a while, if they get too far away, they miss, but not that often!

I have these two with much higher flow than the previous pair. I don't know if that is the reason or if these two are calmer in general, but so far they haven't swapped burrows once.
 
Well, it seems they just needed some time to settle in before starting their silly games: when I came home this evening they had swapped burrows.
I definitely need to find a different pump for them. The current powerhead is way too strong.
 
I think both are females. So I got the last one AC who I suspect to be a male. He is a bit smaller than my two suspected females but behaved like a male and right away kicked one of the females out of her burrow. Unfortunately, the second female wasn't giving up her burrow easily and he got a good beating from her.
 
I never had any female fight with a male, typically the female started a burrow and the male would improve on it. KP Aquatic told me juveniles are normally not sexed so in time one will become a male. I wonder if one of your females has not started into a male change, and does not like your new male?
 
I never had any female fight with a male, typically the female started a burrow and the male would improve on it. KP Aquatic told me juveniles are normally not sexed so in time one will become a male. I wonder if one of your females has not started into a male change, and does not like your new male?

This "female" is a good deal larger than the "male", so I don't see a contradiction in it fighting back.

Does KP Aquatics has any evidence or research papers to support that claim?
I somewhat doubt that they can change sex in the matter of gobies, hawkfish, and dottybacks (bidirectional at any point in their life) or like anthias, damsels & anemonefish (one way only). If there is the potential for change it may be very early in their development, but I think they are more like cardinals or blennies. I'm at this point even doubtful if marine bettas can change sex. Of the two female pairs I have for almost 4 years neither had the larger (dominant) female turn into a male.

I have 2 large female O. randalli (tiger jawfish) for almost 2 years and none of them changed sex. Right now I have a smaller male in QT I plan on putting with them when they move to their new tank. Let's see how that works out.

The BSJ will also get a new, larger tank so that they can spread out more.
 
When KP started selling juveniles I asked what was the benefit and they told me that since they where not developed they still could change sexes. I watched a video once of someone that had hatched and then was able to raise them to maturity. Each one had their burrow about 6" from the other. It was neat to watch a bunch of them in a tank together. The big difference between yellow heads and BSJF is a friend had three pairs of YH in a 200 that coexisted. I had a 300DD with two females and a male and adding a second male seemed like the thing to do but it did not end so well for the second male. I ended up picking up the second male by my hand since he was near death and gave him to my nephew where he recovered. Sooner or later your male will flash which is awesome to watch.
 
When KP started selling juveniles I asked what was the benefit and they told me that since they where not developed they still could change sexes. I watched a video once of someone that had hatched and then was able to raise them to maturity. Each one had their burrow about 6" from the other. It was neat to watch a bunch of them in a tank together. ...

Juvenile BSJ or Yellow Heads?
 
KP only sells what they collect most of the time which is yellow heads. They are better looking than their Pearly cousins from the Caribbean Islands. It would be very nice if someone could start raising BSJF babies, many have tried hopefully someone figures it out
 
KP only sells what they collect most of the time which is yellow heads. They are better looking than their Pearly cousins from the Caribbean Islands. It would be very nice if someone could start raising BSJF babies, many have tried hopefully someone figures it out

Yellow Head Jawfish (O. aurifons) forming pairs that share a burrow is actually atypical for jawfish. All other jawfish I know of live alone in their own burrows with often significant distance between males and females. So I would be hesitant to transfer sex change observations on Yellow Heads straight to other jawfish.

As for breeding BSJ - I don't think their larva are any harder to raise than those of other jawfish. I definitely plan on trying. I got O. randalli to 2 weeks, close to settling down and only failed because I ran out of pods and had to use brine shrimp (which ultimately killed them).
 
All 3 are still alive and get kind of along. The last one has been banned to a corner near the one of the larger he was fighting with and it seems that they found an agreement. Before they were fighting a little, but aside from a bloody lip on the bigger one no permanent damage was done.
Now it's basically down to the larger one threatening the newcomer. During those displays of superiority the larger one sometimes displays a color scheme close to that of flashing males. So I may very well have two males now.
The brighter colored one of the first larger two is definitely a female and she keeps her distance from the two "males".

I hope I will be done soon with "remodeling" the fish-room so that I can give them a larger tank.

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Judging by their behavior I'm now fairly certain that I have two females (the two larger ones) and one male (the smaller one I added later). At this point the small one is certainly the dominant one.
 
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