Hatching BBS...

[BallAquatics]

For years I have used the instructions and guidelines for hatching brine shrimp cysts outlined on the Brine Shrimp Direct site. (http://www.brineshrimpdirect.com/Hatching-Brine-Shrimp-Cysts-c169.html).  It's a method that has always worked well for me and I didn't have any reason to change.

That said, about a month ago I was perusing through Mike Hellweg's book "Culturing Live Foods: A Step-by-Step Guide for Culturing One's Own Food for the Home Aquarium".  In his directions for hatching BBS, he adds a few drops of bleach to each culture.  Since the other culture methods that I have tried from the book work well, I thought I'd give it a go.  I highly recommend this book to anyone interested in cluturing live food for your fishes.

It seems to have increased my hatch rates slightly and also seems to keep my hatching equipment cleaner and easier to clean up between batches.  Has anyone else tried or heard of using bleach in your BBS cultures?  What have your results been?

   http://www.amazon.com/Culturing-Live-Foods-Step-Step/dp/0793806550

Dennis

[Jdmcfast]

I have recently started doing this also, something I heard from evan. It definitely helps with clean up in between cycles

[Frank The Plumber]

Does the bleach just dissipate over the time to hatch?

[BillT]

It may have some thing to do with decapsulating of cysts. All decapsulation techniques that I am aware of use bleach to remove the shell.

The cysts have a chitin-containing shell. This is a chemical common to almost all inverts with an exoskeleton (crunchy on the outside), like insects, crustaceans, and surprisingly nematodes.
Chitin can be dissolved by bleach. Presumably a weak bleach solution will do some dissolving of the cyst shell, making it easier for the developing nauplii to get out.

The bleach could also kill some of the bacteria adhering to the cysts and generally in the hatching container. A cleaner hatching chamber may be more healthy for the baby BS.

Bacteria on the surfaces of cysts have been shown to occasionally have bacteria on their surface that can cause disease in freshwater fish.

What is his recommended bleach dosage?

[BillT]

Does the bleach just dissipate over the time to hatch?

Bleach is an oxidizer and would presumably react with organics in there and get used up.
This is how it kills bacteria also.

[BallAquatics]

Does the bleach just dissipate over the time to hatch?

That's what I'm assuming.  Remember back in the day before chloramine, the chlorine would out gas from aerated city water within a 24 hour period.... same as hatch time.

Dennis

[BallAquatics]

What is his recommended bleach dosage?

3 or 4 drops per liter of water.  The book also lists the reason you stated... 

1) ...a weak bleach solution will do some dissolving of the cyst shell, making it easier for the developing nauplii to get out.

2)...The bleach could also kill some of the bacteria adhering to the cysts.

You're good Bill!

Dennis

[BillT]

Thanks Dennis.

First heard about bleach dissolving chitiin in a Drosophila (fruit fly) genetics lab where I was injecting DNA in to fly eggs with a microelectrode to make transgenic flies.
The microelectrodes are thin weak tubes of glass with a tip opening of 0.1 to 1 micron (1/1,000 of a mm) filled with DNA juice. The eggs had a chitin shell that had to be dissolved off to get the electrode in.

Same principle.