Back from the brink

[BallAquatics]

Almost lost my daphnia this summer due to the heat.  When everything settled down, I found 4 or 5 young adults in a cory fry tank tucked away on a bottom shelf.

I'm thinking about selling some culture kits on AquaBid so I shot a video of todays collection.  Currently, I've got 4 ten gallon culture tanks running and they each get harvested every 3rd day.  I'm guessing around 25 thousand daphnia harvest daily.

Dennis

[Mugwump]

Looks like pea soup....now that's a bunch ya got there......

[PaulineMi]

That's a lot of daphnia!  What size fish eat them?  They seem kind of big but I couldn't really tell.

[LizStreithorst]

I thought that they looked big, too.  I always thought they were only for fry and very small fish.

[BallAquatics]

What size fish eat them?  They seem kind of big but I couldn't really tell.

You can't really see the medium and small sized ones in the video.  The full grown adults are just slightly less than a quarter of an inch, (0.20 in).  From there they run all the way down to slightly smaller than newly hatched brine shrimp.  Newly-hatched fry of most freshwater fish species can ingest very young daphnia as their initial food.

Even my biggest fish, (6 inches),  go after them with a vengeance.  They are highly nutritious with a protein content of around 50% dry weight and a fat content of 20-27%.

I have replaced hatching BBS with fry tanks containing green water and daphnia.  The fry eat the green water until large enough to take the young daphnia, typically several days before they would be eating BBS.  With each adult daphnia producing around 200 offspring every other day, the fry have a constant source of live food.  As the daphnia filter impurities from the water, they will also clean-up any excess prepared foods offered to the fry and can be target "loaded" with whatever you'd like the fry to be eating.

I've always liked to spawn and raise my fish in a more "natural" way, and I've been very happy with the results that these methods are producing.

Dennis