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Large GSP commercial breeding! Must read!

Posted: Wed Feb 18, 2009 7:11 pm
by define999
UF experts breed puffer fish in captivity; pet trade and genetics research could benefit

GAINESVILLE, Fla. — Spotted green puffer fish seldom reproduce in captivity, but University of Florida experts have created the first commercial breeding method reported in the United States, a move that could benefit the tropical fish industry and genetics researchers.
A UF team investigated the species at the request of producers, who hope to breed some of the estimated quarter million spotted green puffers sold annually to North American hobbyists and researchers, said Craig Watson, director of UF’s Tropical Aquaculture Laboratory in Ruskin, part of the Institute of Food and Agricultural Sciences.
“The supply has been variable and sometimes quite limited because they’re wild-collected, mostly in Thailand,” Watson said. “So this was a good species for us to investigate.”
Watson, who led the research team, will present findings today at a World Aquaculture Society meeting in Seattle.
Native to brackish waters in South and Southeast Asia, the fish grows to about six inches. When frightened, its body rapidly inflates into a spiny ball.
It has the smallest genome of any vertebrate that has been genetically sequenced, about one-tenth the size of the human genome, Watson said. Some genomics researchers use it as a model animal. But because only juveniles and adults have been available, the species had little value in fields such as embryology and genetics.
UF’s method could enable scientists to study the fish from fertilization, he said. It could also let them trace a puffer’s lineage back several generations, to study inherited traits. Other animals are used for genetics research, including the zebrafish, another popular aquarium fish, said Hugues Roest Crollius, a research scientist with the Ecole Normale Supérieure in Paris. So it’s unknown how many scientists will embrace the puffer.
“The people who jump on it will have very specific questions, when genes are expressed and where,” said Roest Crollius, who helped sequence the fish’s genome. “It will be of real interest for people who want to take advantage of the compact genome for techniques based on molecular genetics.”
An important first step, he said, is to show the fish can be used for transgenic experiments. One basic study involves adding a reporter gene — such as the gene that produces green fluorescent protein — to a specific gene sequence in a developing puffer. By observing when and where the green fluorescent protein appears, scientists can learn about the function of the puffer gene sequence they’ve targeted.
Watson hopes to see such studies performed soon. He’s secured U.S. Department of Agriculture funding to test whether the captive breeding method works in goldfish.
The method, known as ovarian lavage, is a twist on an older approach to breeding commercially valuable fish that won’t spawn naturally in captivity, Watson said.
In the standard approach, breeders inject female fish with a chemical that promotes egg development, he said. The eggs are gently removed and fertilized.
Spotted green puffers aren’t suitable for injection because they have little muscle mass and their skin is unusually elastic. So the UF team used a catheter to introduce the chemical directly to the female’s ovaries. After several trials they reached nearly 100 percent success in egg fertilization and hatching, he said.
They’ve demonstrated the method for several Florida producers, including Marty Tanner, owner of Plant City’s Aquatica Tropicals Inc.
Tanner plans to sell spotted green puffers to the pet and research markets.

Re: Large GSP commercial breeding! Must read!

Posted: Wed Feb 18, 2009 8:36 pm
by pinkfloydpuffer
Wow! That's so cool!!!

Re: Large GSP commercial breeding! Must read!

Posted: Wed Feb 18, 2009 9:05 pm
by Myaj
Okay, but here's the real question that you notice they didn't mention...

How are they figuring out which ones are males and which ones are females???

Re: Large GSP commercial breeding! Must read!

Posted: Wed Feb 18, 2009 9:07 pm
by crazedpuffer
Probably doing blood tests, that seems a bit tedious though?
I wonder what sg they have them at.

Re: Large GSP commercial breeding! Must read!

Posted: Wed Feb 18, 2009 9:10 pm
by Myaj
We need a member from the Seattle area to attend the meeting and try to get more info!!! LOL

Re: Large GSP commercial breeding! Must read!

Posted: Thu Feb 19, 2009 1:27 am
by Pufferpunk
So they're using invetro fertilization? Cool!

Re: Large GSP commercial breeding! Must read!

Posted: Thu Feb 19, 2009 2:28 am
by Corvus
That's pretty awesome. I'm sure the method will be published in detail soon in some scientific magazine if it is not already... I'll have a look.

Re: Large GSP commercial breeding! Must read!

Posted: Thu Feb 19, 2009 2:35 am
by Corvus
250,000 are imported each year into the US? I guess most die within the first months.

Re: Large GSP commercial breeding! Must read!

Posted: Thu Feb 19, 2009 3:17 am
by Myaj
Pretty sad huh?

I think that's the reason so many of us have high hopes of breeding them in captivity, so they don't have to be yanked out of their natural habitats. It seems weird that someone finally discovered how to breed and raise GSP fry, but for the purpose of studying DNA sequencing.

I'm really, really curious to learn how they are sexing them though. Not to mention feeding the fry.

Re: Large GSP commercial breeding! Must read!

Posted: Thu Feb 19, 2009 3:33 am
by Corvus
Yes pretty sad.

I think feeding pufferfish fry is not a big deal for such a lab, but I am too very interested in the gender topic. Also if there are males and females at all, if they are simultaneous hermaphrodites or if they are first females then males (or the other way round) and are treated with hormones to get a specific gender... so many possibilities... can't wait for the publication.

Re: Large GSP commercial breeding! Must read!

Posted: Thu Feb 19, 2009 3:45 am
by julianchan
That is awesome.....Brings a tear to my eye. But then again...having a puffer from where I grew up makes me kinda appreciate him more too....(I was born and raised in SE Asia..)

Re: Large GSP commercial breeding! Must read!

Posted: Thu Feb 19, 2009 3:58 am
by recombinantrider
I want to read that article too. I am quite curious what size catheter they have used to deliver the hormone into the uterus though, I mean, seriously, how could that be done when I can't even find the genital orifice of my GSP?

Found one more link with a baby GSP picture:
http://news.ufl.edu/2009/02/17/puffer-fish/

Re: Large GSP commercial breeding! Must read!

Posted: Thu Feb 19, 2009 10:06 am
by marksrush
Fascinating. I'm excited to hear how this all progresses.

Re: Large GSP commercial breeding! Must read!

Posted: Thu Feb 19, 2009 11:01 am
by Agnate
Could they be using a form of ultrasound or something to check? I don't think it'd be very difficult to sedate and then check them when you're set up for it, but it could be expensive, I suppose. It'd be neat if they were actually hermaphrodites, because then it wouldn't matter if we called them he or she; the owner would always be right! ^_^

I'll wait for Corvus' detailed summary, as I can't imagine I'd understand half of what is mentioned in the report.

Re: Large GSP commercial breeding! Must read!

Posted: Thu Feb 19, 2009 11:33 am
by Corvus
Seems their report is not published, yet. Could take a while...

The idea of hermaphrodites came, because males and females of T. nigroviridis apparently cannot be told apart by their DNA (have discussed that in another post). Hermaphrodism would be one explanation for this matter.

I don't think ultrasound would work, I think it's too difficult to tell apart male and female gonads, but I do not know for sure.

What I found from looking for a report is that Japanese call them Midorifugu and that there are even claims (I guess even in the magazine Nature) that many of those sold are bred in artifical ponds in Thailand.

@recombinantrider: There is only one opening, the anus on these fishes, no additional genital orifice.

The presentation was last Tuesday, 2pm .