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GSP Breeding articles please
Posted: Thu Apr 29, 2010 2:27 pm
by purplecandle
Nick, I have read some of the articles and studies you have..but I still have a few q's..
I want to re-read the articles, but now I cannot find them...Could you (or anyone please post the links)---specifically the GSP breeding articles
I know that the sperm is viable in Marine, but for some reason I have a different impression about a few things...
And since my house is full of GSPs..I wanna make sure I get it..
THANKS!!!
Sorry to start a new thread for this..but I was getting confused
Re: GSP Breeding articles please
Posted: Thu Apr 29, 2010 2:51 pm
by Nick
Moved to "breeding"
Re: GSP Breeding articles please
Posted: Thu Apr 29, 2010 2:53 pm
by Nick
This is the Word of Scientist on the thing, it is an email send from Craig Watson to Jase. The reason you don't see the information on the spawning water conditions is because it isn't there, that was inside information the good lab director gave us, or specifically, gave Jase.
We have a paper in review with Marine Genomics outlining reproduction, but here are the highlights:
They are marine spawners (we are using 33ppt). The eggs are 0.5 mm in diameter, pale yellow, and become adhesive within minutes after hitting the water. At 78 degrees F, they hatch in about 72 hours. The fry do not eat for the first three days, and on day 4 start eating rotifers. On day 4 we started feeding artemia. After a few weeks we ween them onto flake food.
They are very fecund, having 20% of their body weight in eggs. A 10 gram female will produce over 7,000 eggs.
The females are fairly obvious when gravid as they are much fatter than the males, but we have gotten sperm out of what we thought were "females" (they were fat males). I recommend taking them off feed for a few days before trying to sex them as food in their bellies can be easily confused with eggs.
We attempted natural spawning for over a year, and then standard induced spawning techniques using injections, all to no avail. We developed a new technique (which we will also be publishing) we are calling "ovarian lavage" whereby we flood the ovaries with HCG, a spawning aid, and the females are ovulating ~36 hours later. We are then expressing the eggs and sperm into a bowl, adding seawater to trigger the sperm, and then broadcasting the eggs into aquaria.
We just spawned several of our first generation fish that were 11 months old.
The methods are not suitable for the average hobbyist, but we are working with several experienced producers here in Florida to have them available in commercial quantities in the near future. If anyone succeeds in a natural spawn, I would be interested in hearing about it. I chased freshwater spawning based on some early posts on your forum and some anecdotal info from Maylaysia, but assure you they are marine spawners, as the sperm is esentially nonmotile in fresh, and very active at 33ppt.
Hope this helps.
Craig Watson, Director
Tropical Aquaculture Laboratory
University of Florida
Re: GSP Breeding articles please
Posted: Thu Apr 29, 2010 3:18 pm
by purplecandle
ok, thanks..
You know this makes perfect sense now..
When you look at the aerial maps of where GSPs come from...there is much more sea than river...and the rivers feed so much from the sea..that most likely there is much more brackish than fresh.
Perhaps going into light brackish and fresh as juvenilles is a defense mechanism for avoiding larger sea predetors..plus I would imagine that a river would offer more places to hide.
If that is the case, perhaps GSPs as juveniles should be in marine, but do the smart thing instead and run to hide..smart little fish

Re: GSP Breeding articles please
Posted: Thu Apr 29, 2010 4:04 pm
by Ajepalmer
purplecandle wrote:ok, thanks..
You know this makes perfect sense now..
When you look at the aerial maps of where GSPs come from...there is much more sea than river...and the rivers feed so much from the sea..that most likely there is much more brackish than fresh.
Perhaps going into light brackish and fresh as juvenilles is a defense mechanism for avoiding larger sea predetors..plus I would imagine that a river would offer more places to hide.
If that is the case, perhaps GSPs as juveniles should be in marine, but do the smart thing instead and run to hide..smart little fish

lol I wonder though if they could adapt to be schooling fish if they were to go into marine. Such as sardines are tiny but together make giant schools. (oh god i hope im right in that sardines are saltwater) 7,000 babies per female would make some impressive schools if there is a mating season of say 5,000+ females having babies.
Re: GSP Breeding articles please
Posted: Thu Apr 29, 2010 4:06 pm
by Nick
Perhaps one reason marine spawning is a good adaption for these guys is how small their fry are. I think there's a lot more microbes they can feed on in those regions, you get plankton. Then they move upriver as soon as they are big enough to eat more substantial food, and are big enough to start looking like meals. I wonder just how much time they spend moving up and down the rivers, if they stake off solid territories to which they return. No way to know what territories look like in the wild, even. They could be circles, ellipses, L's, even long, meandering paths for all we know.
So, who's going to build the GPS for GSP implant so we can track the movements of a wild specimen?
Most likely at the fry stage they just drift with the plankton, not quite schooling but no aggression.