Backyard Aquaponics
A place to discuss aquaponics

Aeon, i had uploaded a research paper here http://www.backyardaquaponics.com/forum ... &file_id=7
It dealt more specifically with NATURAL queues for breeding, and how to replicate them (hence no hormones)

I'd assume that the hormones are only available under vet prescription

You do know that the egg count from one silver perch female is between 100,000 and 250,000 ?

Grow the excess fry for a week or so then feed back to the fish

Very efficient

i wonder if the'll take their own. I think they are very nice to their own......

Mini fish cakes one thinks.

if you know anyone with barra...they would love babie perch if you have too many

Thanks steve,
I read the paper - its quite interesting really and makes sense that the fish have to belive there is enough water via a flood in the river and at higher temps before its safe enough for more babies to be produced. (i dont know how I'd go simulating a flood from within a 4 foot tank though). Ahh nature, its very complicated stuff.

Re hormones,
I'm not sure vets would stock human growth hormone - I have a feeling it would be supplied from specialist labs but i could be wrong. Reassuring to know some of the fish we buy to eat are injected with human growth hormone extracted from the urine of pregnant women, isnt it?
(Tilapia looking more appealing once again....)
Cheers,
Aeon

Did you know that commercially tilapia girl fish have thier sex reversed with methyl testosterone becasue boy fish grow to twice the size in the same time?

RE: flooding a 4 ft tank.........apparently all you need is to have a rise in water level. so keep it half full before spawing time, then fill it. Many tropical aquarium fish respond to this trick and spawn.

The hard bit is using water that has flowed over dry ground from the summer. Apparently its a compund released by water flowing over the dry earth that is the main trigger. An no, i don't think baking some earth in the oven will do, they have identified the compund (group of aromatics), its the same ones that give the first rains that "the rains are here" smell in autumn. Did lots of googling on it....what was it called......petrichor.....of which a major constituant is Methyl Octyl Ketone , which is also found in the rue plant.

Quite possibly the rantings of a mad man (me), but it took me hours to find all that stuff, so it only seems right that i post it somewhere

Steve

Well please continue ranting as it keeps me very motivated- I love it when I read this kind of reply- I can hear myself going "hooray!" then "bummer!" with every line as my plans are given hope then crushed in a single swoop.
"And I would've got away with it too if it wasnt for those pesky aromatics..."
I'm going to try a guy who was listed in the 2004 NSW aquaculture directory as a native fish breeder in Sydney - lets hope he's still in business.

Don't give it up yet!

One train of thought is that the silica rocks (or any porus rock for that matter) absorbs these volatiles which apparently may be given off by the grasses and vegetation growing and dying over the summer. Then when the rains come (undecided if it is the peak in humidity and the lowering of atmospheric pressure, or the rain itself) the absorbed volatile oils are released and washed down to the water. (much the same waythat activated carbon when fully saturated can under certain conditions release captured impurities).

Now, my logic is thus: seeing as i can remember getting this "summer rain" smell (i think everyone knows it) then it may still be possible to do on a small scale by keeping some hydroton or gravel in a shallow tray in the garden over summer, with the tray connected to the tank in anticipation of the rains. Its probably a lot of stuffing around when you can just shoot them up, but i like trying these things just so i can say "eureka" "can't be done" is the ultimate challenge

Steve

not quite a flood but you could change to trout and have them swimming up against the current, close one eye and lean slightly to the left - tis easier to picture

Steve where is the document to download for the instructions on breeding Jade Perch?

Nothing since 2006, surely there must be something on hobbyists breeding jades by now.

Bump. Any update on this??

Native australian fish cannot be bred in tanks without hormone injection.