Yellowheaded Jawfish
- Thread starter d9sccr
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David M
New member
How do you like that Mr Moe ! I just sold a book for you and you haven't even written it yet 
MP- About a year ago Morgman and I bought a total of 13 of them at retail for about $90 ea. Lost every one. Dang that hurt. Recently they have been available at wholesale for $50 ea. I am going to LA July 10 and will be looking for them.
Are the Marine Center fish captive bred????
MP- About a year ago Morgman and I bought a total of 13 of them at retail for about $90 ea. Lost every one. Dang that hurt. Recently they have been available at wholesale for $50 ea. I am going to LA July 10 and will be looking for them.
Are the Marine Center fish captive bred????
mwp
In Memoriam
As far as I know, no - marine center fish are probably WC like every other one I've seen.
Sucks to hear you lost ALL those fish! How'd it happen?
David, do you have the head morphology diagram that clearly shows the dimorphism between male and female jawfish? Shoot me an email and I'll email it back to you!
Matt
Sucks to hear you lost ALL those fish! How'd it happen?
David, do you have the head morphology diagram that clearly shows the dimorphism between male and female jawfish? Shoot me an email and I'll email it back to you!
Matt
Jens Kallmeyer
New member
@ Martin and bandeng
Thanks for the info!
Unfortunately I did not see the eggs this morning
Jens
Thanks for the info!
Unfortunately I did not see the eggs this morning
Jens
MP is correct about the male leaving the eggs in the burrow, either to feed or in response to stress, or both. I did see this before, and the male did reappear with the eggs. However, I don't know how common this is. One would think with a 6 to 9 day incubation time, that the male would need a bite now and then. In fact, this is probably why unexperienced males often lose their eggs. The reproductive drive may not be strong enough yet to overcome the drive for food. Just a guess.
A book on jawfish, hmmmm... that would be a labor of love. It wouldn't be for awhile yet, just getting started. In this day and age it would probalby be better (and less expensive) just to put it on the internet. A book on breeding a specific species of fish is seldom a best seller. Although thanks, David, for your marketing efforts.
In my 6 I can't difinatively see differences in head morphology, they are large enough to show this if it is a real difference, maybe is it just apparent during prespawning and spawning times. Hopefully I'll find out. There are differences in total size, may be developmental rather than sexual, and differences in the "plumposity" of the abdomens, which may have more to do with feeding than gonad development. It may be possible to sex them by looking at the "shadow" of the gonad through the abdomenal wall. We did this with neon gobies, the male had a triangular,white gonad while the female had a larger, rounded, and yellowish gonad. Jaw fish are larger, much, and have a denser abdomenal wall so it may be a stretch. May be possible when reproductively active or near to it.
On feeding the larvae, it's possible to do it with rotifers (enriched) and sparsely fed enriched brine shrimp. I think too much new hatch brine shrimp is not good for any marine larval fish but sometimes that's the best that can be done. I use a finly shaved frozen shrimp as soon as the post larvae can take it, and down here I can use sorted wild plankton, which really works well if you can avoid the predators and competators. I think it's also important to add a substrate of sand and rock to the larval tank as soon as the larvae settle.
I forgot about the breeders regristry. That is a good source of information and the jawfish info is very good.
Martin
A book on jawfish, hmmmm... that would be a labor of love. It wouldn't be for awhile yet, just getting started. In this day and age it would probalby be better (and less expensive) just to put it on the internet. A book on breeding a specific species of fish is seldom a best seller. Although thanks, David, for your marketing efforts.
In my 6 I can't difinatively see differences in head morphology, they are large enough to show this if it is a real difference, maybe is it just apparent during prespawning and spawning times. Hopefully I'll find out. There are differences in total size, may be developmental rather than sexual, and differences in the "plumposity" of the abdomens, which may have more to do with feeding than gonad development. It may be possible to sex them by looking at the "shadow" of the gonad through the abdomenal wall. We did this with neon gobies, the male had a triangular,white gonad while the female had a larger, rounded, and yellowish gonad. Jaw fish are larger, much, and have a denser abdomenal wall so it may be a stretch. May be possible when reproductively active or near to it.
On feeding the larvae, it's possible to do it with rotifers (enriched) and sparsely fed enriched brine shrimp. I think too much new hatch brine shrimp is not good for any marine larval fish but sometimes that's the best that can be done. I use a finly shaved frozen shrimp as soon as the post larvae can take it, and down here I can use sorted wild plankton, which really works well if you can avoid the predators and competators. I think it's also important to add a substrate of sand and rock to the larval tank as soon as the larvae settle.
I forgot about the breeders regristry. That is a good source of information and the jawfish info is very good.
Martin
mwp
In Memoriam
Martin, I'll have to email you the diagram on head morphology in jawfish..I found it as part of a larger PDF on fish reproduction somewhere out there on the internet. It clearly shows a porportional difference in the morphology of the maxilary between the sexes (i.e. porportionally longer in males) as well as the larger head proportional to the rest of the body. I'm sure you've seen the references on Blue Dots indicating a coloration shift in males during the breeding season as well - boy would that make getting pair easy if some collector would make the effort.
Your metion of morphology shifting during prespawn is definitley possible - i.e. in the various cardinalfish sp. I'm working with, the males seem to "enlarge" the buccal cavity by displacing something in their lower jaw prior to spawning...they all swim around looking like they're holding a very "small" brood in there 6-12 hours before spawning actually happens. In my Apogon margaritophorus, the male that doesn't get the spawn simply returns to normal shortly after the ordeal is complete.
That Neon Goby sexing info is priceless..makes my thoughts of trying Neons a bit easier to stomach since I can probably sort through some neons at a LFS and get a male and female!
Matt
Your metion of morphology shifting during prespawn is definitley possible - i.e. in the various cardinalfish sp. I'm working with, the males seem to "enlarge" the buccal cavity by displacing something in their lower jaw prior to spawning...they all swim around looking like they're holding a very "small" brood in there 6-12 hours before spawning actually happens. In my Apogon margaritophorus, the male that doesn't get the spawn simply returns to normal shortly after the ordeal is complete.
That Neon Goby sexing info is priceless..makes my thoughts of trying Neons a bit easier to stomach since I can probably sort through some neons at a LFS and get a male and female!
Matt
mwp
In Memoriam
http://mentor.lscf.ucsb.edu/course/fall/eemb106/L10L11L12reproduction05print.pdf - that's the PDF that has a the diagram of male and female jawfish dimorphism.
MP
MP
I know you all can get there, but here is a color version of that
http://mentor.lscf.ucsb.edu/course/fall/eemb106/L10L11L12reproduction05.pdf
The whole site is great ! Take a walk as it´s shareware http://mentor.lscf.ucsb.edu/course/fall/eemb106/
Anderson.
http://mentor.lscf.ucsb.edu/course/fall/eemb106/L10L11L12reproduction05.pdf
The whole site is great ! Take a walk as it´s shareware http://mentor.lscf.ucsb.edu/course/fall/eemb106/
Anderson.
mwp
In Memoriam
<a href=showthread.php?s=&postid=7633879#post7633879 target=_blank>Originally posted</a> by bandeng
OK, in looking at Bandeng's photograph, it's blurry but once I looked at the diagram again I noticed a striking detail...basically the upper maxilary on the male in the diagram reaches all the way back to the first ray of the dorsal fin...in the female there is a BIG gap. Looking at Bandeng's photo, it's kinda blurred but in his suspected male it look as though the maxiliary again reaches much further back towards the dorsal fin than it does on the female. Perhaps that's the characteristic to look for? I'm curious, Martin, if you apply that "formula" how do your 6 jawfish stack up?
Matt
Morgman
New member
Martin,
How is your new book going? If I remember correctly you were working on a new book. Also, weren't you working on system that replicated tidal flows or something to that nature?? How is that going??
A jawfish question-
Do you think jaws need a mix of fine particle sand with a larger gravel? I am sure you have seen them diving in the Keys. I would guess, by looking to their environment, they need a fine sand with a mix of substrate. Just curious, how your jaws are adapting to your tank's substrate.
thanks,
Morgan
How is your new book going? If I remember correctly you were working on a new book. Also, weren't you working on system that replicated tidal flows or something to that nature?? How is that going??
A jawfish question-
Do you think jaws need a mix of fine particle sand with a larger gravel? I am sure you have seen them diving in the Keys. I would guess, by looking to their environment, they need a fine sand with a mix of substrate. Just curious, how your jaws are adapting to your tank's substrate.
thanks,
Morgan
That's a very good program on fish reproduction. Covers all the basics. I've been looking at the jaws on my jawfish. It's very hard to see the extent and structure of the maxilary because of the relative smoothness of the jaw fit and the uniform coloration in this area. I think I can detect a difference in the length of the upper maxilary, but I'm not sure. It does seem like there is some territorial agression in what seems to be the females, and that makes some sense since the females would compete for a limited resource, the males. Once a male is with eggs, he is unavailable for some time, I wonder how frequently the male holds eggs, even if he does drop the eggs in a burrow to feed, it seems like he would still be limited in his ability to feed while holding eggs. I'll try to get a better look today, maybe if I clean the algae off the glass......
I made up the substrate of a mix of fine sand, coarse sand, and numerous burried and surface rocks. And added some short tubes of 3/4 inch pvc pipe, the pipe gives them a head start on the burrows. This seems to work well.
I really put a lot of effort into the rewrite of the Reference book over the last few years. I now have about 1000 pages written on it. There is a large section on the "marine multi environment tank" as well. But I don't know though, if I'll finish it. The new book by Delbeek and Sprung has covered a lot of the ground that I have included, and in these days of the internet, much of this (and a lot more) is available at the touch of key stoke, and I don't know that I now want to get more heavily into the investment of publishing, storing, selling and shipping another book. That's a big committment of time and money, and I'm now working very hard on the culture lab and the Diadema culture project as well. So the book is now churning in the dilemma zone. Maybe I'll figure out a way to just put it on the internet, we'll see....
Now I have to go change out the water pump on the outboard motor.
Martin
I made up the substrate of a mix of fine sand, coarse sand, and numerous burried and surface rocks. And added some short tubes of 3/4 inch pvc pipe, the pipe gives them a head start on the burrows. This seems to work well.
I really put a lot of effort into the rewrite of the Reference book over the last few years. I now have about 1000 pages written on it. There is a large section on the "marine multi environment tank" as well. But I don't know though, if I'll finish it. The new book by Delbeek and Sprung has covered a lot of the ground that I have included, and in these days of the internet, much of this (and a lot more) is available at the touch of key stoke, and I don't know that I now want to get more heavily into the investment of publishing, storing, selling and shipping another book. That's a big committment of time and money, and I'm now working very hard on the culture lab and the Diadema culture project as well. So the book is now churning in the dilemma zone. Maybe I'll figure out a way to just put it on the internet, we'll see....
Now I have to go change out the water pump on the outboard motor.
Martin
NicoleC
New member
Martin, you may want to consider on-demand printing since the book is already pretty much written. No storage and handling for you, you can still sell online at places like Amazon.com, and there's very little up front cost. Of course, each copy will cost more, but you'll have a contract specifying what those costs are and for how long.
mwp
In Memoriam
I haven't been able to convince Renee that we should get these, so I figured I might as well post 'em up here - 1 Mated Pair Yellowhead (pearly) Jawfish, on eBay, about 1 day left on the auction, currently at $40+25 shipping.
http://cgi.ebay.com/Yellowhead-Jawf...7QQihZ006QQcategoryZ66795QQrdZ1QQcmdZViewItem
(I think I have enough larvae to deal with anyways...will wait to find that pair of Blue Dots!)
MP
http://cgi.ebay.com/Yellowhead-Jawf...7QQihZ006QQcategoryZ66795QQrdZ1QQcmdZViewItem
(I think I have enough larvae to deal with anyways...will wait to find that pair of Blue Dots!)
MP
FishGuttz
New member
Matt,
collecting breeding pairs seems easy until there are none available, go for it! You don't have to raise the fry until you are ready, it might take a year or months for them to settle down and breed anyway, right?
My LFS has blue dot gobies for sale. Do you think they are easier to breed?
collecting breeding pairs seems easy until there are none available, go for it! You don't have to raise the fry until you are ready, it might take a year or months for them to settle down and breed anyway, right?
My LFS has blue dot gobies for sale. Do you think they are easier to breed?
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