|
|
|
|
#27
06/28/2006, 01:08 PM
|
|||
|
|||
|
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
__________________
MMoe |
|
#28
06/28/2006, 01:53 PM
|
|||
|
|||
|
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 |
|
#29
06/28/2006, 09:10 PM
|
|||
|
|||
|
http://mentor.lscf.ucsb.edu/course/f...ion05print.pdf - that's the PDF that has a the diagram of male and female jawfish dimorphism.
MP |
|
#31
06/28/2006, 11:04 PM
|
|||
|
|||
|
I know you all can get there, but here is a color version of that
http://mentor.lscf.ucsb.edu/course/f...oduction05.pdf The whole site is great ! Take a walk as it´s shareware http://mentor.lscf.ucsb.edu/course/fall/eemb106/ Anderson.
__________________
"Posso não saber de nada mas suspeito de muita coisa..." |
|
#33
06/28/2006, 11:15 PM
|
|||
|
|||
|
Quote:
Matt |
|
#35
06/29/2006, 05:19 PM
|
|||
|
|||
|
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 |
|
#36
06/30/2006, 08:40 AM
|
|||
|
|||
|
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
__________________
MMoe |
|
#37
06/30/2006, 10:13 PM
|
|||
|
|||
|
I hope the book will be available somehow, maybe on springerlink.com like the Sadovy article Matt keeps referencing. I think its 30 bucks. I don't know the specifics of licensing on this site. It's an option. I 'd love to see all 1000 pages myself!!
-Doug |
|
#38
06/30/2006, 10:44 PM
|
|||
|
|||
|
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.
__________________
Don't count your gobies before they've metamorphasized. |
|
#39
07/07/2006, 01:25 PM
|
|||
|
|||
|
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-Jawfi...QQcmdZViewItem (I think I have enough larvae to deal with anyways...will wait to find that pair of Blue Dots!) MP |
|
#40
07/08/2006, 09:47 AM
|
|||
|
|||
|
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? |
|
#42
07/10/2006, 09:05 AM
|
|||
|
|||
|
A quick note on my yellowheads, all 6 are doing fine, there is a lot of interaction, "musical burrows" going on. The plumposity index on the known females in increasing. The largest female had a few hydrated eggs extrude from her vent yesterday. I would expected spawing (full moon) but that did not happen. It may be that the three largest are females and that an active male is not present. Don't know. I may have to go back to the reef and make a greater effort to collect a few males. It's possible that the females are more susceptable to the collecting techniques and so we selectively collect females. Have to work on that.
Martin
__________________
MMoe |
|
#45
08/05/2006, 03:05 PM
|
|||
|
|||
|
Well, things are still cooking. It's been a very busy time with the Diadema projects, dove for 7 hours yesterday collecting juveniles for transfer to deeper reefs, and collected some large brood stock urchins. The jawfish are doing fine, getting fat and playing musical burrows. The big female has produced eggs twice, and each time the male has eaten them.
The first time I didn't know what happened, my supposition of who was a female and who was a male was placed in doubt because the male? became fat, and the female? thined out. Then a couple of weeks later the female! got fat again and the male! stayed thin. I had the good fortune to observe the fat female enter the male's burrow with the male, then 15 minutes later the female, now thin, left the burrow. Hot dog, I though, we got eggs! Later the male peeked out and I looked for eggs in his mouth. Couldn't see any. Maybe they were not hydrated yet, this didn't seem right, however. Then he left the burrow and wow, did he have a fat tummy.... Now I knew that he ate the eggs. Bummer, and he was large enough to have had experience with this. So I changed out the burrows. I had set up pvc pipe tubes, one 1" tube and a few 3/4th " tubes. I got to thinking, may be they can't "do their thing" in such a tight space, so I changed out the tube burrows for four cavern type burrows, and once they settled down from the storm and found the new burrows, they really seem to like them. Interesting, though, right after I changed out the burrows, they would go back to the site of the old burrows and try to enter the now nonexistant burrows tail first, without success, of course. It took a half day for them to figure it all out and claim a burrow, the little guy got the short end of the stick (as usual) and had to make a burrow of his own in a less desirable neighborhood, he now sports a Diadema spine burried in his side. Doesn't seem to affect him, though, still feed and fights as usual. So now I'm waiting for the next spawn and hopefully their new digs (and that's what they are....) will be more condusive to successful spawning and oral incubation. We'll see.... Martin
__________________
MMoe |
|
#47
08/06/2006, 12:32 PM
|
|||
|
|||
|
Ah, the Diadema project. In a nutshell, 98% of the long spined reef sea urchins, Diadema antillarum, died in 13 months in 1983. The plague covered the huge area of the tropical western Atlantic from the entire Caribbean, the Gulf of Mexico, the Bahamas, the Florida Keys and on up to Bermuda. This reef urchin was the keystone herbivoir for the coral reefs of this region. For eons, these coral reefs evolved with corals creating the physical structure of the reefs and Diadema (and other herbviors) controling alge growth and creating a working balance between the two photosynthetic elements of the reef, the coral and the algae. Coral growth is slow and stable and algae growth is fast and loose. Once the Diadema were gone, algae could, and did, overgrow and out grow the corals and the reefs become dominated by algae rather than coral.
In some areas of the Caribbean, where Diadema are coming back in small patches, where they are abundant, coral growth is retuning and the reefs are changing dominance once again from algae to coral. So the Diadema project here in the Keys, where Diadema are not returning naturally (for many reasons) we are trying to: 1. save those Diadema that settle on the shallow rubble zones of the reefs by moving and concentrating them on deeper reef areas, and 2. to develop the hatchery techniques that will allow us to create "Diadema reefs", a sort of living coral reef laboratories all along the Keys. (This is the main thrust of my culture lab, but I am also playing with yellowhead jawfish and blackcap basslets.) We will establish these reefs with an initial population of Diadema at levels of 1 to 3 urchins per square meter, and then maintain these levels with the addition of juveniles to make up for a lack of natural recquitment. Then as the Diadema spawn naturally and the larval load in the water increases, natural settlement hopefully will be able to maintain these pioneer populations and create new populations on favorable reef areas. Can we do it? Don't know, but it you don't try, then you certainly can't do it, and the value of the Keys coral reefs to Florida and the nation certainly requires that we try. To get more info on the situation you can visit: http://www.marineland.com/seascope/ss2003_issue4.pdf where there is an older article I wrote for SeaScope that will fill in most of thedetails. Martin
__________________
MMoe |
|
#49
08/07/2006, 09:40 AM
|
|||
|
|||
|
Martin,
Glad to see you posting here. Your book on clownfish was the very first book I bought in this hobby  Due to time contraints I haven't tried clownfish yet, but I have started collecting breeding invertebrates Fabulous project you are attempting on the Diadema antillarum. Good luck and if you setup a website to track progress of the project, please let us know, I for one would be very interested in following it. Any plans on periodic updates any other way? Brian
__________________
Currently redesigning my 90 gallon tank system to support coral and invertebrate breeding. Click on my red house to see the thread with the progress. |
|
#50
08/07/2006, 11:44 AM
|
|||
|
|||
|
Quote:
 don´t tell me I missed that Martin´s book!
__________________
Luis A M |
|
|
Anyone ?
Linear Mode
