Brine Shrimp Failure

[cat]

I have had problems with latest batch of brine shrimp. These the same eggs I have always used.

Do the eggs have a use by date? These are not old and have been kept in the fridge until use.

Am getting very poor hatching rates after always have excellent results.

[Caryl]

Do you mean it is the same container or a different container of the same brand? Brine shrimp eggs do have a use-by date but I understand they keep for years under good conditions.

[cat]

Same eggs from same container. They have been stored in the fridge for approx 8 months. Was working fine until this few batchs of angels born and now getting shocking results. Have had to revert to feeding fry microworms. Am using same sea salt as always. No changes that I can think of.

[graeme]

Here's a bit of info i have been given from a source, and ive followed by it myself and every time i get between a 85%-95% hatchrate. :lol:

Ideal Cyst Hatching Conditions

Water Salinity: 25ppt

Water Temperature: 28 deg C

Water pH: 8.2--8.6

Light Level: >2000 lux at surface,from either flourescent or

incandescent lamp.

Oxygen Level: air bubbled at 200ml to 600ml / minute / L

hatching vessel water,may need to be adjusted

depending on hatching vessel configuration.

Hatching Vessel: Irmhoff cone or similar shaped vessel (inverted

ice cream cone.)

Cyst Density: <2g dry cysts / L of hatching vessel water.

Cysts may need periodic washing back into hatching vessel water with a wash bottle depending on the volume of air bubbling and hatching vessel configuration.

Independent hatching experiments performed provide the following results.

Hatching efficiency ( number of nauplii per gram of cysts )

For standard cysts: >280,000

For 175 cysts: >340,000

Hatching % (% of nauplii that hatch from cysts)

For standard cysts >85%

For 175 cysts >93%

Hatching synchrony (time between 10% and 90% hatching )

For standard cysts <8 hrs

For 175 cysts <6hrs

if anyone is interest in bryneshrimp egg's, email me and ill get back to you.

[ajbroome]

Cat said...

> I have had problems with latest batch of brine shrimp.

If you want to get some eggs off me, to try, then let me know.

This will at least tell you if there's something wrong with your eggs.

Andrew.

[Pegasus]

Hi Cat,

This is the method that I use for small batches.

1/ Fill a two litre container with tank water (warm) and suspend in the tank. (76 to 80deg works best... cooler will take longer to hatch.

2/ Add three tablespoons of sea salt.

3/ Add 1/2 teaspoon of baking soda.

4/ Aerate well for a few minutes to mix contents.

5/ Add 1/2 level spoonful of cysts.

6/ Aerate well for 12 to 18hrs and shrimp will hatch.

In my tests light seems to make no difference whatsoever, but this is just my opinion, but I have never had a bad hatch, even from old eggs.