Culturing D. pulex and moina outside?

[Molch]

I ordered a D. pulex and a moina colony in addition to the D. magna I already have. Couple of questions:

- could moina and pulex be cultured together in the same tub? Or would one outcompete the other?

- can these be cultured outside on my porch? My magna are inside, but I have no more room there for another daphnia tub. Temps in our Alaskan summer can range from mid-70ies (what we call a "heat wave") to near freezing, with 24 hrs of daylight until August. Temps in their tub could possibly fluctuate between maybe 40 and 70 F over several days' periods. Can the lil' things tolerate that kind of abuse?

 

[caleb]

My presumed D. pulex (collected locally) do well outside here in NE England- daytime temperatures are about 17C at the moment, night about 10C. They started reproducing when daytime temperatures were about 10C, and survived our unusually hard winter (their container froze from all sides, and from the bottom up).

 

[Jennewt]

A big tub of water heats and cools slowly, so it will tend to have a temperature that is roughly the average of the day/night temps. It will fluctuate, but not as much as the air temp does. I think D. pulex and moina will tolerate this just fine, but the average may be too cool for magna.

My daphnia cultures are mixed-species, containing D. pulex, D. magna, ostracods, and possibly other species. This was not intentional, it's just what I've ended up with over the years, and it seems to work. The species vary with the seasons, with the smaller daphnia dominating in the winter and the D. magna dominating in the summer. The magna completely disappear in winter, but magically re-appear when things warm up.