
Originally Posted by
JoeDigiorgio
Andy raised mandarins on Acartia tonsa 'by accident' but he encouraged me in a brief conversation that parvo was a better choice because of ease of culture over A tonsa.
Doh! I think that is the second time I made that error….

Originally Posted by
JoeDigiorgio
On an only slightly unrelated topic, I still want to attempt to culture A tonsa on ciliates fed pastes to experiment with this theory but I can't find O marina to do it with. I'd like to challenge copepod cultures fed O marina against one another with only the diet of the O marina as the variables.
If I ever see O marina pop up in my cultures, I'll send you some. I used to have it, but stopped trying to culture it when I went back to live phyto. Is O marina considered a ciliate? It's so much smaller, I just assumed it was a different critter.

Originally Posted by
JoeDigiorgio
I didn't intend to use pastes with parvo at all, but instead A panamensis because from my research it is small enough for mandarins to take, but not scooters.
That could really work, but Chad has A. panamensis growing on pastes already. I don't know if he is using O. marina to get there. I think there are some threads about using O. marina to get algae paste nutrition to A. panamensis. Either here or on MOFIB.

Originally Posted by
JoeDigiorgio
I get that they're more than vessels of algae to our larvae but is there any hard research regarding to what extent copepods are actually able to convert fats from one form to another...and then pass them on to their offspring?
None that I know of. I haven't looked. There was a paper about O. marina, though, and its ability to convert fatty acids to something useful. I'll see if I can find it, cause the details are fuzzy in my poor brain.

Originally Posted by
JoeDigiorgio
For example, would n1 parvo naups (never yet actually eaten anything) from a culture fed only Iso have the exact same nutrient profile as naups of the same stage from a culture of adults fed a more balanced set of live algaes? Is that information even available? I don't know.
Neither do I, but it is also important to ask if any difference in copepod nutrient profile would be critical to the larvae, or not. It might be worthwhile to gather information from people who have succeeded compared to those who have failed, in raising something on A. panamensis or P. crassirostris, and what they fed the copepod brood stock. See if there is a corelation of what the adult copepods ate, with success or failure of their nauplii as prey items. Find out if it matters.

Originally Posted by
JoeDigiorgio
All I'm saying is I find it hard to believe that an organism cultured on a single skewed feed such as Iso could present a totally balanced profile for another far more advanced organism, let alone one attempting to undergo dramatic transformation. A diet of only Isochrysis is enough to grow and reproduce for parvocalanus and acartia. Is that food chain sufficient for all larvae? I have to think not. Sorry for the long post, I had an espresso later than I should have

I get what you are saying, and can only offer that P. crassirostris has been tried with other algaes as singe food sources, and it grows better with Isochrysis than the other phytos tested. Chad Clayton once mentioned that cultures grow better with iso AND tetraselmis or chaeto co-fed, but the Iso part seems critical to the success of the critter.
I don't know if adding another phyto to their diet would produce more nutritious nauplii, perhaps it would, but it could just as easily make no difference at all. I could be that the critical nutrient that makes a copepod's nauplii successful prey items for some larvae is already supplied by the Isochrysis diet, and that the enhanced fecundity noticed by adding another phyto. is irrelevant to the larval diet.
That said, I see no harm in feeding a variety of good photos to the copepods. I do it with whatever I have growing, and at every chance I get.
Interesting discussion. thanks.