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  • Live food or fry, pics

    Hello,
    I'm attaching some pics of different acuatic organism I have been culturing and/or harvesting from a big pond to feed the fry during almost their first month of live. Didn't manage to get decent pictures of rotifers and ciliates, which were the first live food for the fry.
    Interestingly, there are several species of water fleas belonging to different genus like Daphnia and Moina, and some of these species are very different in size as you can see in one picture. Moina is smaller and seem to be one of the best options for small fry.
    I'm not sure whether the smaller water flea species in the picture is Moina or not.
    On the other hand Hydra is a natural predator of water fleas. Although it has been cited as predator of Koi fry, I believe this is not the case due to differences in size.
    Diego
    Attached Files
    Diego Jordano
    Cordoba, Spain
    A.E.K. web site http://www.elkoi.com
    pers. web site http://es.geocities.com/estanqueskois/
  • #2

    Great pictures Diego.


    In the first pictures, it's stacked full of them. Is this just a droplet of water, which is naturally full of them?
    Regards, Bob
    ><{{{{º> ><{{{{º> ><{{{{º>
    <º}}}}>< <º}}}}><

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    • #3

      Diego,

      This year, I have gone with a completely artifical fry diet. Green water with rotifers is best.

      First food is hard boiled egg yoke, some bacteria, and citrus juice mixed with water. Then I move into a larval diet of high protein - 100 micron and then a 200 micron. Then about 24-30 days from hatch, start them on a high protein fish meal powder. Around day 50, micro pellets. Small pellet koi food by day 60, and the fry are then around 1 inch up to 3 inches.

      I move them to a grow out pond/ tank between day 50 and 60.

      They seem to be growing very well this year. I will post pics as soon as I can.

      I have some that I hatched in late Feburary that are now pushing 4 inches!

      Jeff

      Comment

      • #4

        Originally posted by Bob Hart
        Great pictures Diego.


        In the first pictures, it's stacked full of them. Is this just a droplet of water, which is naturally full of them?
        Hello Bob,
        it is a picture of Artemia nauplii, just hatched from cyst incubated in a 8 liters culture jar. What you see in the picture is what can be seen in a drop of a high density Artemia culture. Today I have been decapsulating Artemia cysts for the first time. Just curious, I weighted a random sample of 0.001 g of cysts and counted them: 236. That means that on average there must be around 200000 cysts per gram. In my Artemia cultures I've been incubating at least 5 g of cyst in a 8 liters jar.

        Diego
        Diego Jordano
        Cordoba, Spain
        A.E.K. web site http://www.elkoi.com
        pers. web site http://es.geocities.com/estanqueskois/

        Comment

        • #5

          If you can get your hands on it - try cyclops-ezzz. It is a frozen cyclops paste with added vitamins and color ehancers- really awesome stuff- I highly recommend it! JR

          Comment

          • #6

            What about brine shrimp? These were said to me to be easy to cultivate and the eggs can be easily bought.

            I've put some in saline water, aerated it and applied light above the bowl. 36 hours later the eggs still 'look' the same. Is it me, or have the 'hatched' but they still just dont look any different????

            Fry are a week old now.
            Regards, Bob
            ><{{{{º> ><{{{{º> ><{{{{º>
            <º}}}}>< <º}}}}><

            Comment

            • #7

              I have been using the frozen cyclopeze for about a year. A bit pricy, but good stuff. Koi and goldfish do not go for it as much as marine species, but it still works. I recently bought the cyclopeze freeze dried flake because the shipping cost is much less and it is easier to handle. Guess what, the fish hate it. I don't understand why, but cyprinids won't touch it, live bearers pick at it reluctantly and the clowns are not too crazy about it either.

              -steve hopkins

              Comment

              • #8

                How are you all 'cultivating' the live food for your fry?

                I'm just using brine shrimp, but I am not noticing any great growth, so am also interested in how you 'cultivate'?

                Green water must be full or 'things' for Koi to feed upon, is it as simple as just letting some water have heavy sun and going green? Perhaps aerate it, but not filtered? Remove some 'green' to feed the Koi, top-up the container and let them multiply?

                Any thoughts appreciated - thanks
                Regards, Bob
                ><{{{{º> ><{{{{º> ><{{{{º>
                <º}}}}>< <º}}}}><

                Comment

                • #9

                  Bob,

                  The way you approach live feed cultivation sort of depends on the resources at your disposal.

                  The easiest thing is to develop the green water with its associated zooplankton and stock the fry right into the green water. The touble is that the fry density has to be very low to keep them from grazing all the zooplankton so that the zooplankton can no longer reproduce fast enough to keep up. The stocking density would need to be in the order of 50 to 100 fry per cubic meter. This is basically how fry are reared in mud ponds.

                  If space constraints demand that the fish be stocked at much higher densities, then the zooplankton needs to be cultivated in separate containers (tanks or ponds or whatever). A second container with at least twice the volume as the fry container can be allowed to develop a phytoplankton bloom (green water). Zooplankton such as rotifers daphnia and copepods will find their way there and begin to multiply. If left unchecked, the zooplankton will eat all the phytoplankton and then their population will crash. The crash can be postponed by removing the zooplankton at frequent intervals using a 50 micron screen on plankton net. Of course, the larger the plankton culture the more zooplankton you can harvest and the less you will have to rely on off-the-shelf feeds. The trick is to remove enough zooplankton to prevent them from depleting the phytoplankton, but not remove so many zooplankton that the rate of reproduction (repopulation) declines.

                  A third approach would be to use three containers (tanks or ponds or whatever) of about equal size. The first container houses the fry. The second container houses a zooplankton culture. The third container houses a phytoplankton culture. At frequent intervals (about daily) 25 to 50% of the zooplankton container is drained through a 50 micron seive or net and the bugs are fed to the fry. The zooplankton container is then refilled with green water from the phytoplankton container. The phytoplankton container is refilled with new water and is fertilized.

                  I find that this third approach works very well with Moina, a smallish type of daphnia. It also works with rotifers, but the rotifers are a little too small for koi fry after the first few days. Sometimes it works with copepods but they are finicky. The percentage of the zooplankton tank harvested each day (25-50%) depends on the doubling (reproduction) rate of the zooplankton which, in turn, depends on the zooplankton species, temperature, and quality of the green water. All green water is not created equal and the algae species composition determines how well it will nourish zooplankton.

                  Using this third approach, the phytoplankton container will crash if becomes comtaminated with zooplankton (they eat everything all at once). Therefore, a hardy species of fish are placed in the phytoplankton container to eat any zooplankton that develop there. In my hands, tilapia work best and guppies are a close second. In a cooler climate, you may want to use a more temperate species - anything that eats zooplankton and can tolerate the fertilizer additions. You may be able to use a few koi fry to keep the phytoplankton culture free of zooplankton, but I have never tried it.

                  Check these out:
                  http://govdocs.aquake.org/cgi/repri...604/6040230.pdf
                  http://govdocs.aquake.org/cgi/repri...614/6140140.pdf
                  http://govdocs.aquake.org/cgi/repri...614/6140150.pdf
                  http://govdocs.aquake.org/cgi/repri...725/7250110.pdf

                  You might also want to check the threads:
                  "Koi-Food" especially the later parts from back in February 2005;
                  "Comments on reaing koi fry in green water" from about September 2004;
                  and others I cannot remember.

                  Comment

                  • #10

                    Steve,

                    Thanks for the very detailed answer. I can see it's not quite as simple as I thought, just for the few thousand fry I have.

                    Really got me thinking now though and thanks again for the links.
                    Regards, Bob
                    ><{{{{º> ><{{{{º> ><{{{{º>
                    <º}}}}>< <º}}}}><

                    Comment

                    • #11

                      Daphnia culture

                      Hi Bob,
                      sorry for this delayed reply.
                      You can find very good information on Daphnia culture in
                      http://www.starnet2.neostrada.pl/tarkus/txt/dafnia.txt

                      and on Moina culture in
                      http://edis.ifas.ufl.edu/pdffiles/FA/FA02400.pdf

                      Good luck
                      Diego Jordano
                      Cordoba, Spain
                      A.E.K. web site http://www.elkoi.com
                      pers. web site http://es.geocities.com/estanqueskois/

                      Comment

                      • #12

                        Thanks Diego, loads of great information.

                        Do you breed Daphnia for your fry?
                        Regards, Bob
                        ><{{{{º> ><{{{{º> ><{{{{º>
                        <º}}}}>< <º}}}}><

                        Comment

                        • #13

                          Great photos. I used a toothpick to separate brine shrimp in order to get a picture of just one.

                          I started feeding brine shrimp as soon as the koi fry got 5 days old. I fed this until the fry hit 15 days old. Then started feeding powered flakes with the brine shrimp (not sure if they ate this or not). At day 25 switched exclusively to mini pellets. 4 tablespoons of pellets every 12 hours. As I no longer see pellets in the water, I increase the amount.

                          After 2 days of pellets the water went green pretty quick. About 10,000 fry in a 3,000 gallon pond. Fry are 3/4" long now.

                          Comment

                          • #14

                            Originally posted by Bob Hart
                            Thanks Diego, loads of great information.

                            Do you breed Daphnia for your fry?
                            Yes, I have been culturing Daphnia and other organisms as live food for the fry.

                            I started culturing just protozoa and rotifers. This is the first source of living prey for the fry. I managed to get nice huge cultures right on the rearing tanks before the eggs hatched. There are also good sources of information on the web showing how to start and maintain such cultures.

                            It is important to start Moina and Daphnia cultures before the fry need them as live food.
                            I collected water samples from several natural sources and scooped Daphnia individuals to start new cultures. Gradually I modified the original cultures to get Daphnia cultures. Eventually some copepods were also thriving on the culturing tanks. However, these 4 tanks quickly proved to be insufficient to support the increasingly higher harvesting rate. Then I started harvesting zooplancton in a big pond, it was dominated by copepods and there were at least two different species of water fleas. Most important, I could harvest the pond whithout catching potential predators for the fry.
                            Besides, i have been culturing Artemia from dry cysts, but this year it has been rather late (fry already rather big) and much less frequent than in the past year. One day I tried the decapsulation method and it works very well, however more time is needed to complete the decapsulation procedure. It has the big advantage that the hard egg shells are completely eliminated, hence the small fry can't eat them and die.
                            Cultures of Moina are very interesting. Moina are smaller than Daphnia (better pray for small fry), and it is possible to maintain high density cultures.
                            I'm not using live food because the fry are too large, but my exhausted cultures of Daphnia and Copepods are flourishing again.
                            Diego
                            Diego Jordano
                            Cordoba, Spain
                            A.E.K. web site http://www.elkoi.com
                            pers. web site http://es.geocities.com/estanqueskois/

                            Comment

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