AARRGGHH! brineshrimp won't hatch!

[auntiejude]

I started out with a bottle of 'artemia revolution' decapsulated brinesherimp eggs - brilliant stuff, hatching in 24-36 hours and plenty of them. But I ran out, and it's expensive stuff.

So I have some dry capsulated eggs, I hatched them before but they take longer - more like 48 hours+. I set up 2 batches, as described in every tutorial here and on youtube, and yesterday I had some live BBS, but still loads of unhatched eggs. I decided to leave them another day as I had the last of the decapsulated BBS hatched and ready to go.

BUT today when I went to harvest the BBS from the dry eggs I had about 50/50 unhatched eggs and dead BBS - just brown/grey gritty eggs and orange mush - not a wriggly little thing in sight

What did I do wrong? I used 1tbsp of salt per L as usual, kept them at 24C as usual, kept them in the bubbling hatchery as usual - all exactly the same as always.
Or could it be that the eggs are no good? I thought they were supposed to survive for years as they come from salt lakes that can remain dry for a long time.

Any insight would be useful.

 

[xxianxx]

Sounds like you got a **** batch of eggs. What was the supposed hatching rate on them ? You can feed bbs on actvated yeast, a single drop for a liter is about right, I have had the odd batch where they hatched at diffferent times, just feed them till they all hatch. Just remember that they are most nutricious straight after they hatch and before they consume their yolk sack. If you speak to some fish breeders they dont feed bbs over six hours after hatching for this reason.

 

[Jennewt]

Even the dry capsulated eggs do deteriorate over time. Hatch rate goes down gradually over time. That wouldn't explain why the hatched ones died so quickly though.

 

[willowcat]

Up until two days ago I have been putting in these small amounts of salt. I contacted my person that I buy my decap from. This is what he told me. I tried it his way and what a difference!!!!! I will cut and paste.


------HIM-----
You mix half a cup of seasalt per gallon of water. You can put up to a
cap full of eggs per hatch in a two liter container. 24 hours is enough
if you have a light source on it the entire time your incubating. Light
makes a difference in the hatch out times. If when you get a meter you
can decrease your hatch out times by lowering/finetunning your salinity.

---------ME-------
I got to thinking. I prepare a salt bath for my amphibians. I mimic the University of Kentucky. I contacted them eairler this week, since I don't have a salilnity meter, yet. They sent me the info--4ppt or 1.004 sg. 1 cup of salt and 1 cup of baking soda in a 45 gallon barrel of water. Not to question your knowing what you are talking about. You are the farmer. (saltwater farmer- at that). So how come a half a cup of salt per gallon of water, and your parameters on the instruction guideline is between 1.017-1.025? How many ppt is that?
Again, I am just learning the world of salt.
Thank you,
Trace


------HIM------



Just two different forms of measurement. Like inches and centimeters. Full sea strength salinity would be around 35ppt. The mix that I suggested to you (1/2 cup per gallon) is 25- 30 ppt.
-------------Me---to you------
His web site is www.aquaculturenurseryfarms.com Tell him I sent you. He is very helpful. Oh....I have had a can of caps in my fridge (for back up), for about 7-8 years. It still produces. I haven't use the higher amount of salts though. Should get a better yield. Also---I have read when using capped bbs if the salt is not high enough then they have trouble getting out of the shell. Here is another place to look for good info.----real good read----http://www.brineshrimpdirect.com/res-hatching-c169.html
Trace:frog:

 

[auntiejude]

The batch of eggs I had claimed a 95% hatch rate - but I wouldn't always believe those claims...

OK, converting that to measurements I can use, salt is half a cup =120g in a gallon=4.5L, so for 1.5L it's about 40g - twice the amount I have been using.

I'm guessing that would account for the dead brineshrimp and lack of hatching?

I will have another go tonight with the extra salt. Failing that I'll have to get a fresh bacth of eggs - although the ones I have I bought 6 months ago.

Thanks for your input.