Jawfish behavior.

ARCkeeper

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I have had a Caribbean mustache jawfish (O. lonchurus) in my 125 gal. tank since October. It has settled in nicely, has a bold personality and is a good eater. With no warning or indication that anything was wrong, it suddenly disappeared. I saw no sign that the burrow was occupied, but there was no ammonia spike to indicate it had died in the burrow. As time went on I began to suspect that it had found some opening to jump out of the tank and the cats had gotten it. After a week, I began to see it lurking just inside the mouth of the burrow but it wouldn't come out to eat.

My working theory is that it is a female and this is part of the breeding cycle. The average temp in the tank went up about half a degree recently with the onset of warmer weather, and 2 days before it went missing I changed the photoperiod in the tank so the lights would be on before I left for work. I had a bluespotted jawfish that would sometimes disappear for a couple of weeks at a time and I later confirmed it was a female.

My suspicions seem to have been confirmed when it finally came out to eat yesterday. The abdomen is extremely distended but it was actively eating for the first time in over two weeks. Other than the huge belly it seems fine. In fact, its colors were much brighter than normal.

My concerns are than the fish may not be gravid and there is something wrong. If it is gravid, will it eventually expel or reabsorb the eggs? How likely is it the fish will become egg-bound?

Has anyone else had a similar experience?
 
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In way of an update, the jawfish came out of its burrow this morning and was eating ravenously. The abdominal distention was much reduced but still noticeable. Its vent was slightly distended and looked a little red. Mild prolapse? I had to go to work, so I couldn't watch it for as long as I would have liked.

When I got home, the fish was back to lurking just inside the burrow. It came out to feed as soon as the mysis hit the water, but was a bit more timid than normal. Its abdomen was almost back to normal size although the vent is still slightly distended and a little pink.

So far everything I have observed is consistent with my theory that this is part of the breeding cycle. She went off feed and disappeared into her burrow to develop eggs. Under normal circumstances she would have paired up and laid her eggs which the male would pick up in his mouth and return to his burrow to incubate. Without an available mate, she held onto the eggs as long as possible before expelling them.

I am encouraged that its (her?) appearance and behavior seems to be returning to normal.
 
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As I write this, my jawfish is pretty much back to normal, and is even getting her girlish figure back. I grew up in a very ethnic Polish neighborhood in southwest Detroit and she reminds me of the old babcias (grandmothers) hanging out on the porch all day gathering gossip and judging everyone.

All in all she was holed up in her burrow for just over three weeks. My LFS is trying to find me another mustache jawfish, and with a little luck I'll get a male. I don't plan to try to raise the fry, but I think it will be healthier for her to lay her eggs normally.
 

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I have one as well. I had a few days a few months ago where mine stopped eating for a few days. Also was very worried, as I waited a long time to get one. After a few days just started eating again. Did not notice any abdomen swelling, but as mentioned for those couple of days it stayed lower in its burrow. Here’s a pic of mine from a few months ago.
 

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I have one as well. I had a few days a few months ago where mine stopped eating for a few days. Also was very worried, as I waited a long time to get one. After a few days just started eating again. Did not notice any abdomen swelling, but as mentioned for those couple of days it stayed lower in its burrow. Here’s a pic of mine from a few months ago.
They're a really fun fish! I just wish they were easier to come by.
 

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Really cool. I’m on a waiting list for one of these as well. Gonna set up a tank to showcase Jaws and their behavior. It’s not gonna look like the typical reef tank because that’s not where they live in the wild. Not knocking folks keeping them in regular setups just think it’ll be amazing to see them in all their glory with deep sand and no towering rocks around them. Never seen anybody do it. Maybe somebody here has?
 
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Really cool. I’m on a waiting list for one of these as well. Gonna set up a tank to showcase Jaws and their behavior. It’s not gonna look like the typical reef tank because that’s not where they live in the wild. Not knocking folks keeping them in regular setups just think it’ll be amazing to see them in all their glory with deep sand and no towering rocks around them. Never seen anybody do it. Maybe somebody here has?
Mine actually chose to build her burrow in a crevice between two of the tallest rocks in the tank. I'll try to get some pics to post soon. I've been in contact with KP Aquatics who said they do collect them but had to make a special trip to the deeper water to find them. My LFS is watching for them to come up on Dynasty Marine's availability list. My first came from Diver's Den.
 

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