Brine hatch numbers

Discussion in 'Freshwater Health, Disease and Nutrition' started by tjudy, Aug 5, 2011.

  1. tjudy

    tjudy Executive Board Staff Member

    The topic of brine hatch rates and cost effectiveness keeps coming up in conversation, and I answered a post on the MAS forum with this:

    Randy described the process to decapsulate eggs, which renders 100% of the eggs edible for the fish. Hatch rates will improve slightly as well. The big advantage to live decap is they do not require the separation of inedible (shell and unhatched cyst) from the edible. There is the added cost of the chemicals needed to decap and store the eggs. Let's call that number a round $3 per pound (probably high if you do this a lot and buy the chems in large quantities). The result would change the chart to this:

    90% 10 grams/hatch $49/can 45 hatches $1.09/hatch
    80% 10 grams/hatch $38/can 45 hatches $.84/hatch (based upon my price... which is BSD's case lot price)
    75% 10 grams/hatch $35/can 45 hatches $.78/hatch
    65% 10 grams/hatch $29/can 45 hatches $.64/hatch

    I find it enlightening that the best savings for making decap is only $.06/hatch using the lowest grade cyst. The difference is too minimal (in my opinion) to bother decapsulating anything higher than the 65% cyst.
  2. Marine590622

    Marine590622 Advisory Board Staff Member

    Nicely summerized Ted.

    But what about cysts that have been sitting around open in the fish room for years. My initial tests with this process are because I really struggle with hatching brine shrimp. Using non-decapsulated cysts, they end product is just too messy in my hands. The can I used was a can of cysts you gave me years ago as you were unhappy with the hatch rate, I tried these cysts between 6 and 10 time before I set the can on a shelf and forgot about them.

    Before I tried the decapsulation process, I tried them one more time and I would bet the process yielded less then 5%.

    After the decapsulation process, I would say these former cysts are yeilding near 35 to 40% (my old eyes you know), but the advantage here is even in the hatch fails the decpsulated cyst is a valuable food source.

    Now admittedly with my first run I took a pound - say 12 teaspoons and ended up with maybe 10% of the cysts because of the loss in straining. I would not argue that the process is going to be economically better then working with regular cysts, but it does leave you with a product where you can hatch it out and rinse and feed. No worries about unhatch cysts getting into the tank and bloating or binding up one of your fry. No mess from shells.

    I also suspect that overfeeding with this is less likely to cause a hydra outbreak, but that is just supposition on my part.
  3. Marine590622

    Marine590622 Advisory Board Staff Member

    BTW if you have an old stale can of cysts laying around that you are not happy with the hatch rate. Give them to me instead of throwing them out, I will decapsulate them and split the end product with you.
  4. tjudy

    tjudy Executive Board Staff Member

    my quote...

    I was making the point that if I were decapsulating I would not bother buying expensive cysts... there is no advantage monetarily, even if you can get 100% hatch from decapsulating them. Old eggs would fall into the under 65%...
  5. fishlady

    fishlady Executive Board

    Ok I have read a couple of post on here about hatching brine shrimp eggs and I still have some questions.
    If I am working with 4 cups of water how much salt would I need?
    Is it better to use hard or soft water?
    What temp should the water be or does it matter?
    1 teaspoon of eggs = how much brine shrimp?

    What exactly is decapsulating, and what are the benefits?
  6. Narwhal72

    Narwhal72 Well-Known Member

    1. I would use 2 Tbsp of salt per 4 cups of water but the mix doesn't have to be exact.
    2. Doesn't matter once you put the salt in it's hard anyways. Tap water works fine.
    3. The warmer the better. Brine shrimp hatch quicker when the water is in the 80's but low to mid 70's is acceptable.
    4. 1 tsp of eggs = approximately 140,000 brine shrimp nauplii.

    Decapsulation is the dissolving of the protective cyst around the nauplii with bleach. This makes the hatching process easier for the nauplii and improves hatch rate. It also allows you to feed the unhatched cysts to fish directly.

  7. fishlady

    fishlady Executive Board

    Thanks that helps.
  8. fishlady

    fishlady Executive Board

    I'm going to try decapsulating and see how it goes. I think that will be a good project for tomorrow. Any tips I should know about?

    Going to try this process unless someone knows of a better one.
    Last edited: Feb 2, 2016
  9. Narwhal72

    Narwhal72 Well-Known Member

    Keep in mind that you don't have to do the vinegar step if you are intending to hatch them right away. If you are going to decapsulate a bunch and then store the cysts in the fridge until hatching then you need to do the vinegar step.

    I don't store mine. Soak, bleach, rinse, hatch.
  10. fishlady

    fishlady Executive Board

    good to know. I didn't do this the other day like I had planned because I didn't have the vinegar. The part about storing them in all that salt puzzles me a bit as well.
  11. Narwhal72

    Narwhal72 Well-Known Member

    The vinegar neutralizes any remaining bleach. The salt keeps the eggs from hatching while you store them.
  12. Narwhal72

    Narwhal72 Well-Known Member

    I did some more research on the vinegar and it looks like it neutralizes the bleach by turning it into hypochlorous acid. Which in turn breaks down into chlorine gas.

    While this is probably harmless in very small quantities like a dish full of brine shrimp nauplii, under no circumstances should you do this in a larger quantity like a bucket of floor cleaner or a washing machine!

    Your much better off using a little sodium thiosulfate (any aquarium dechlorinator) than vinegar.
    Dave and Eric N like this.
  13. fishlady

    fishlady Executive Board

    Can I just soak, bleach, rinse, feed?

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