Phytoplankton - Nutritional Value

[Marauder-m]

I'm looking into Phytoplankton culture and was wondering if there is any particular type of phyto that is best in terms of nutritional value?
Having looked around a bit I have found a source of Nannochloropsis oculata available as a starter culture. Can anyone suggest some pro's and con's?
These may be a silly questions, but I'm relatively new to the marine aquarium hobby and am making a concerted effort to become more informed. Any and all help will be gratefully received.

[gwen_o_lyn]

I think it's a great question! I don't do the phyto thing so I can't answer.

[Rob]

i dont know if i can answer this specifically, but i will ask our resident algae expert from AlgaGen to answer if he can

[AlgaGen]

There are a number of strains commonly used in aquaculture, Nanno is one, so is Isochrysis galbana (T. iso/C. iso), Chaetoceros spp., Monochrysis lutherii (pavlova), Thalassiosira fluvialis (diatom) amongst others. Nanno is common for several reasons 1) it is relatively easy to grow and, 2) it has a lot of a fatty acid called EPA..great stuff plus a number of other pigments and proteins. Nanno is commonly used for rotifer culture and in green water larval production.

T.iso and C. iso have another fatty acid (as well as accessory pigments, carotenoids, etc.) called DHA which is critical for larval development of a number of different species. T. iso is typically used to raise invertebrates such as clams, oysters. Many fish breeders use this algae to feed to rotifers and artemia as an enrichment. Isochrysis is great food for copepods. People raising other inverts use pavlova and T. iso to feed their rotifers and claim they get better egg production. Isochrysis can be a little bit trickier to grow for some people but I think it is worth it in terms of nutritional content. One advantage is that it handles warm temps fairly well. Consider this…the strain was isolated in or near Vanuatu (or so I was told).

If I were to grow one microalgae it would be the T. iso strain. However, both the T.iso and nanno would be a great combination to have because many organisms need both fatty acids DHA and EPA for healthy growth.

Frank Hoff’s book (Plankton Culture Manual) goes into this. CSIRO has a great culture collection. They have many spp available and probably some very knowledgeable people to talk with.

good luck..

[Marauder-m]

Excellent. Got a whole lot more information than I expected, which is certainly a good thing. One other question. Could one culture a combination of strains in the same batch, or would one expect them to compete for nutrients with one causing the other to starve out? Put another way, is it better to culture each strain separately?

[Rob]

great information Erik, thanks

on a side note, do you sell starter cultures for these?

[AlgaGen]

No, no, thank you Rob : )

We have close to 30 commonly used aquaculture strains for sale, including Isochrysis (tahiatian strain) and Nanno oculata. Our strains for the most part were taken from successful aquaculture projects, cleaned up through the use of antibiotics and then selection off of nutrient agar plates. They are clean but I would not say axenic (without bacteria).

Maurauder, one can culture both spp together but you won't get the "performance" of a monocultured effort. I have been around cultures that were a mixture and one spp would overgrow/outcompete the other. In short, one can do it but I do not recommend it.

[Rob]

if you were to o two spp cultures, would you have to separate them like you would rotifers and phyto for cross contamination reasons?

[AlgaGen]

It depends on how robust your culture system is. You are using those 2L jars with tops which are great. The air creates positive pressure in the container and that in theory should keep contam out. Make sure that each system has dedicated parts. For instance, all parts of your system associated with nanno gets used, even after cleaning, with nanno cultures...repeatedly. Make sure that your hands are clean so that nanno cells attached to your hands do not get put into or near the Iso cultures..that kind of thing. Basically really think about what you are doing and where your hands have been. In this case they could sit fairly close to each other.

Many hatcheries have carboys on shelves above each other, each shelve will have different spp on them. They use lids/caps and blow air in which creates positive pressure. There is no dipping into the cultures but pouring out. Hands are cleaned when switching from one spp to another. They rarely get algal cross contamination.

[Reefbaby]

Hmmm...I may have to think about moving my lab bench back home and into my aquarium room....maybe a cell culture hood for culturing my phytoplankton and some rotating incubators as well?! :-)

[Bernie]

so do cultures crash due to the nutrients being used up? or do they generally crash due to outside contamination?

[fat walrus]

both. but contamination is generally the greater concern.

[Bernie]

so cleaning my paws religiously, cleaning all the eqiupment the same way and splitting on time should be enough to get my cultures past the 4th split mark... maybe... unless my chihuahua is tainting them while I'm at work...

[wildeone]

I don't know if I am doing it correctly, but I am now running three 2 qt containers and I fill them 1/2 full. I harvest the jars 2 & 3 and then divide jar 1 into thirds into jars 2 and 3 and then I add with SW and nutrients. I don't clean my jars everytime I split, I just clean them every third or fourth time. I have made about 4 or 5 gallons thus far.

[Rob]

cleaning the containers and tubes every time is important, you can skip every once and a while if you need to, but at least a rinse should be done.
and splitting into thirds, should work, but will likely make the cultures take longer, but shouldn't be a technical problem with it

[veriann]

what a great thread, straight from the horses mouth too which is nice. thanks eric