How long before jawfish builds burrow?

[2poor2reef]

I changed over a tank to a jawfish species tank and added one Bluespotted Jawfish (o.rosenblatti) about a week ago. The jawfish has done some sand movement but hasn't really begin to dig its burrow yet. For those of you with experience in this area, How long did it take before your jawfish dug its burrow?

I have six inches of oolitic aragonite as a base with two inches of 1 - 4 mm sand on top with small shells mixed though the top two inches and some coral rubble and snail shells on top. Total sand bed depth is about 8 inches. Any info you could provide would be much apreciated.

 

[Anonymous]

This is odd. There is a good chance he has built a burrow out of you eyesite.

Where does he hang out? I have had two Pearly Jawfish and both built a burrow the first night in the tank. They don't always build there burrows were you would like them to. I was fortunate that both my jawfish relocated their burrows to the front of the tank within the first month!

I have never had a bluespotted jawfish. They are a little pricey. Do you know if they are hardier than the pearly jawfish?

 

[2poor2reef]

Thanks Louey. This is my first jawfish so I don't know their relative hardiness. It's eating well and acclimated fine.

I have this particular tank set up as a sand flat. It is totally sand with only one small flat rock in the center. I can see 100% of the surface so I know it hasn't built its burrow yet. It just scooped out two large depressions in the two front corners of the tank and spends all its time in that general area.

Either it's very slow to get down to business or my habitat is not right. I imagine that most folks add them to communal tanks with lots of reef rock but my research indicated that they were normally found in open sand flats. Since it's a species tank I set it up that way. Perhaps that was a mistake.

The Bluespot is a pacific fish and I believe most other species common in the trade are atlantic. With the relative lack of info on them I might be reading general info that does not apply to this species. Someone posted a link to an excellent article in one of the online mags and that's what I modeled my substrate on.

I guess it's possible that it does not feel the need to build a true burrow. It spent all of its time at the front of the tank even when initially introduced and actually moves towards me when I enter the room. There are no other tank inhbitants so it may feel unusually secure but I would still think that it would burrow.

 

[Lynn]

I got a yellow headed jawfish the other day. I first put him in my QT with a yellow watchman goby. He was terrified of the goby and I didn't think I had enough sand in the tank for him to burro. I then did the "no no" and put him in my main tank (I just felt too sorry for him) He seemed pretty scared in the big tank at first and kinda stayed in one corner. I then put in a piece of pvc 3/4 " pipe about 4" long in the front corner of my tank. He took to it the first hour!! He comes out a lot but anytime he is frightened he dives into it. Take a look at the pic of him.

 

[jwtrojan44]

I have a mated pair of yellow heads. They actually excavated three separate dens before settling in one. I had a lone yellow in another tank who had an established den for several monthsd, and then moved out and did what yours is doing. He just dug a crater in a corner of the tank. This lasted only a couple days before he moved again. mY pair have been in the same burrow for over a year. I'm thinking you might want to add some more rock to your tank to give them a couple options. They will normally only excavate where they feel comfortable, so yours may not be too settled yet. I like your idea, and hope to do the same at some point with mine. Fascinating fish.

 

[Lynn]

Can you tell me the difference between the males and females? I would be interested in another if I could pair them up?
thanks

 

[jwtrojan44]

I got lucky with mine. The male is noticeably larger than the female. They each have their own entrance to the burrow and they keep each other away from their entrances. Mine have spawned three times. The male carries the eggs in his mouth. I've never had fry, and likely they are eaten by either the parents or other tank inhabitants, thus my desire to set up a tank devoted solely to these fish.

 

[2poor2reef]

For benefit of those who may search on this species in the future I thought I would record what happened in my case:

I converted a 12g CPR MRT into a dedicated jawfish tank. This tank has a built-in skimmer compartment, a rio 90 for circulation, 36w powercompact lighting, and is fairly tall. I used 6 inches of oolitic aragonite plus 2" of 1-4 mm sand on top, added rubble, snail shells, and broke up a stylophora skeleton to provide debris for a single blue-spotted jawfish. I was trying to replicate a sand flat biotope so there was essentially no rockwork.

The jawfish acclimated well but did not excavate a burrow for about four weeks after intoduction. Instead, it would dig a shallow depression which it would defend (against clean up crew) and in which it would sleep. This depresssion was usually in one of the tank corners but would sometimes be along a side wall. The depression was always scooped against one or more panes of glass, usually in one of the two front corners. The jawfish never cowered when I approached the glass and almost always stayed in full view.

After four weeks it began to excavate a much narrower tunnel in the back right corner opposite of the unobstructed rio 90, in fairly high direct current. It used large pieces of coral skeleton fragment to buttress the top of the tunnel. Two sides of the borrow were exposed by the glass corner of the tank so I used masking tape on the outside glass to provide better privacy, after which the jawfish completed its burrow. It used fragments as large as 2 inches by 1/2 inch in its construction.

I had reasoned that my 12g would be suitable for a lone jawfish specimen since it would not have to share territory with any other vertibrates. But from this experience and in this sand-flat design without use of live rock I suspect that there was not sufficient surface area for the jawfish to feel comfortable initially. I assume this because the jawfish never attempted a single excavation anywhere except against an extreme edge of the sand bed. If I had it to do over again I would use a larger tank.