will copepods eat frozen phytoplankton?

[paparoof]

I've successfully raised Apocylops pods on Nannochloropsis phyto that I've cultured (from Mercer of Montana). So I know that works.

Question here is - if I freeze the fresh phyto into cubes to preserve it longer, will they still eat it (after thawing) and thrive on it?

 

[ichthyogeek]

I believe that it depends on the temperature that you freeze the phyto at, as well as what the phyto is in. You can freeze somce commercial thpes of phyto because they’re in a certain type of solution (I believe glycerol) that makes it harder for the cells to lyse upon freezing. But with homemade batches in a typical home freezer, it may/may not work. You could certainly try freezing a batch, but it would be useful to have a microscope on hand to see if the cells have burst upon freezing and rethawing or not.

 

[paparoof]

Thanks for the reply. I had not considered "what the phyto is in". I'm culturing it in the same water I make up for my tank ([email protected]) so all that salt is going to lower the freezing point isn't it? It'll be interesting to see if it freezes at all in my fridge freezer. Hmm.

I do have a microscope on hand...

 

[amps]

The answer is yes but I'm sure there are some caveats. If you have the ability to concentrate the phyto first, it might help reduce damage from freezing.

I have cultured pods and rotifers entirely off frozen phyto I got from Reed Mariculture. I receive it in large bags and then transfer it into ice cube tray to be frozen, weighed and vacuum packed for later use. The particular product I used was Rotigrow Plus.