Daphnia and brine shrimp questions.

[Joseph S]

That is a pretty good match.

In any case...they've been the only cladocerans I've had any big success with. I could get 100's out of a 5 gallon bucket. They were easy to harvest since they would just hang on the sides so you could take a few nets of them, then pour out some excess water and add new water.

They grew larvae(I've also had moina and I think those are better for larval rearing)...but even the adults were eagerly taken when everyone hit the 4 legged stage.

[AJ]

Ok, I have two 16 gallon rubber maids that I will fill 1/2 to 3/4 full. I will have a airline going into each one. I will feed the daphnia a mixture of 2 parts soy flour and one part yeast. The daphnia magna should be in the mail tomarrow. I also bought some daphnia pluplex eggs as well. I will start up the eggs if both d. magna cultures crash. What other set-ups can be used to hatch brine shrimp besides the two liter bottle?

[pesco]

Daphnia cultures are virtually indestructible. Even if it crushes, drain the water, dry detritus from the bottom of a tank, leave it dry for few weeks and then pour some water in. The best if the water was soft and a bit alkaline. Within few days you'll see some young Daphnia swimming around.
The reason is, when conditions worsens Daphnia produce surviving eggs called ephippia, these eggs are "designed" to survive drought and frost and will hatch as soon as condition get better.

[Heather at HMSG]

Have I missed mention of bloodworm in this thread? Maybe the title is the clue...oops! However, I am about to order some as well as extra supply of live daphnia, for 3 week old axi-poles - do they need chopping? My youngsters are growing VERY fast, & I am about to lose sleep.........AND I only have nine!

Heather

[AJ]

I got my daphnia in the mail today. There was about 50 mixed aged daphnia in each container. I bought two containers. I also bought some eggs. The eggs are in a small bag of what looks like dry dirt. I used a mixture of 2 parts soy flour and one part yeast to feed them. Is it normal for the daphnia to hang out towards the bottom of the cage?

[Cameron Cheri]

Originally Posted by caudatadude28

Is it normal for the daphnia to hang out towards the bottom of the cage?

Yes. My daphnia tend to spend most of their time swimming around the bottom of their tub and occassionly coming up toward the surface of the water.

[AJ]

Oh, good. The soy flour didnt dissolve very well.

[AJ]

So is just yeast a good diet?

[Johnny O. Farnen]

More about the amazing powers of Daphnia...

I know of a spot in the vicinity of Death Valley, actually a trench in an abandoned mine workshop foundation, that has a sustained population of "annual" Daphnia. It only has water in this 6 foot long, one foot deep, one foot wide spot for about three weeks a year, and is in direct sunlight!

DEATH VALLEY!

Now that is some hardy eppiphia!


I use the "crash" culture method quite often to store mine long term often. I find letting the tank/bucket/tub dry out in direct sunlight after all visible movement in the tank has ceased works best. I have also found that glass containers (I use five and ten gallon fish tanks) are best. I suspect that even FDA approved plastics can leach out some Daphnia harmful chemicals over time.


And yes, I have had great luck with plain old live baker's yeast.. I mix up a few tablespoons worth with some water direct from the daphnia culture until it makes a runny suspension that looks kind of like skim milk. Then about once a day, I shake the mixture up really well and I feed about 20mL per gallon by squirting it directly into the tank in such a way as to get good dispersion. Its actually pretty neat to see those little buggers filter the water out clear in a matter of hours! You will know if you are adding too much yeast solution if you get a white goo on the bottom of the tank.

Advantages: Cheap
Easy, year round availability
excellent "bang for your buck"
a little bit of yeast goes a long way
Crashed cultures restart easily after a few weeks drying period.

Disadvantages: Yeast solution must be kept refrigerated
Yeast solution stinks like...well...yeast
Takes a bit of trial and error to get it right (in other words, always have more than one culture going at any one time, staggered out a few weeks apart in rotation)
Its easy to overfeed and WILL crash your culture after a few weeks.
Once you use a container for yeast fed daphnia, I do not recommend using it for anything but that.

Also, I am not sure of your budget or set up, but those HUGE 1 gallon pickle jars make great daphnia culture units and you can often get them for FREE if you ask around at a few mom N pop restaurants. (Unless you can eat a gallon worth of giant dill pickles in a hurry...)

Also, neat trick for harvesting Daphnia: Place a bright light over the culture for about 10 minutes, the daphnia will swim to the light just like brineshrimp, and can be scooped out with a wet brine shrimp net, or some old pantyhose streched over a bit of coat hanger...