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FAQs on Culturing Food Organisms: Techniques

Like a miniature world... or aquarium (!), cultures must be attended to in terms of populations, species, foods, wastes, dissolved gasses...

Producing 'Pods (Amphipod Propagation) Hello Mr. Fenner, <Actually, Scott F. here this afternoon!> My friend has a Mandarin and we want to build a tank to breed worms and pods for her Mandarin. If we do such a thing, can the worms and pods be transferred from my tank to hers, or will they be too small? <Well, they are not large creatures, but they are captured without too much effort. Regardless of their sizes, they will be beneficial to the fish that she's keeping!> What would be the best way to harvest them for the Mandarin in the other tank? <You might want to use a fine mesh net to do some "sweeping" of the bottom of the propagation tank. Even better still, if you could somehow hook up the prop. tank to the display housing the Mandarin, then the animals may very well be swept into the main tank with little or no intervention required on your part. The concept of a refugium is based upon this very need-having an attached system to help process organics and "feed" the display!> The plan is to use a 38 gallon tank with a bag of live sand and some live rock and Caulerpa (sp?) algae. How important is the live rock to getting this going? <A nice quality live rock will be helpful, but you could certainly get by with some "rubble"- small pieces of rock that will provide a nice place for the 'pods to forage. You may also want to use some Chaetomorpha macroalgae, which has a rather dense composition, and forms a network of hiding/feeding/breeding places for these animals> Does it need to be uncured to make sure there still are worms and pods on it? Would cured rock have any left? <Ideally, you'd want cured rock pieces; You can usually convince the staff at your LFS to sell you some "rubble" from the bottom of one of their live rock holding tanks. That will do the job nicely and inexpensively.> Could we seed the tank with like 15 pods from mail order and would that be enough to get the population going? <Sure. That would be a start. You may also want to see if a fishy friend has some available-perhaps in some filter media or rock pieces...> How long would it take to get enough going to feed the mandarin on a regular basis? <Well, these animals have a fairly rapid reproductive cycle, but you're probably talking a couple of months before you could get a sustainable daily harvest> What else would I need to make the tank an optimal tank for worms and pods for mandarin gobies? <Really, not much else. Just make sure that you don't have any fishes that will out-compete the slower Mandarins in their search for these food items. With a lot of patience and attention to some details concerning the "food production", you should have a very successful setup!> Thank you for your advice. Brendgol Majewski <My pleasure, Brendgol! Good luck in your efforts! Regards, Scott F.> Dosing phyto/zoo plankton, culture Hello all, <Howdy> I looked down the other day and realized how much I'm spending on DTs. Ouch. I dose my 400 gal reef per their recommended schedule. I am using it for my filter feeders - feather dusters, various soft corals. I also target feed the frozen Cyclop-eeze to my LPS weekly. <Sounds good.... with a system this size... oh I see this below> I am once again thinking about culturing my own. I looked at the Aqualine Buschke Plankton Light Reactor and Plankton Reactor system, the DIY culture stations (see http://www.reefkeeping.com/issues/2002-07/ds/ for one description), and came across a Zinn Reactor (http://www.reefonline.com.au/shop/product_info.php?products_id=234). The Zinn Reactor seems like the easiest and most painless of the solutions, but I can't find any real information about it. Do you have any thoughts on the different solutions. Is culturing your own such a pain that buying the DTs seems like a bargain after trying? Other thoughts for me? <Is actually... easily done... and a hoot to boot!> Coral List: Capnella, Cladiella, Pachyclavularia, Sarcophyton, Sarcophyton elegans, Euphyllia paradivisa, Euphyllia paranchora, Caulastrea, Fungia, Polyphyllia, Turbinaria peltata. May add over time - Clavularia, Anthelia, Platygyra, Trachyphyllia geoffroyi. Thanks! Larry <I definitely encourage you to try your hand at culture here... I've done this (and am exceedingly lazy...), can be "cook booked" and if you follow simple procedures (principally to avoid contamination) you'll soon be a plankton culturist! Bob Fenner>

Phytoplankton culture and culture density measurement 7/7/06 Hello, <Hi there> I would like to say thank you in advance for your time. I have a few questions with regards to culturing phytoplankton. The purpose is for a small look at invertebrate larvae nutrition requirements. My primary reference is Dr. Toonen's 1996 "Home Breeder's FAQ for Marine Invertebrates". I am not a "real scientist" I originally only wanted to set up a nano-reef, but I got sidetracked while reading. <Sounds good> In establishing my culture, I'm planning to use local natural seawater (I'm on the coast of NC) that I will pasteurize. I am also planning to use the commercial Micro-Algae Grow formula as my nutrient. The phytoplankton cultured will be fed to invertebrate larvae (species as yet undetermined) that are maturing in aerated flasks (also pasteurized NSW, but no other nutrients added). Larvae growth will be measured by optical microscopy. 1. In order to determine if the larvae are feeding, I need to know the density of algae in culture at different points in time following feeding. I can do this by making cell counts, however: A Sedgewick-Rafter counting cell seems too large (1mL volume) for the densities recommended, even a Palmer counting cell (.1mL volume) seems excessive. There are gridded Sedgewick-Rafter cells available, including one from Aquatic Eco-Systems that is reasonably priced. Can I responsibly use a gridded cell? <Yes, I have used these> Or, because I cannot ensure an even distribution of plankton across the grid is this a bad idea? <Will be able to get enough distribution that by randomly counting a number of cells, you should be able to get good approximations> 2. Even allowing for a gridded cell, a microscopic cell count will take time. I know from your site and others, that it is not possible to get an accurate density measurement solely by eying the coloration of the culture, but I got the impression that this had to do with "eyeballing" the culture. I have the opportunity to pick up a used spectrophotometer cheap... If I measure take the absorption at x nm* for different densities of algae, wouldn't I get a reasonably accurate count of algae density? <Yes... a simpler device, a colorimeter (one set wavelength of light for absorption/transmission) will/would even work here. You can/should develop your own "curve" for density (counted) versus readings with this tool> *-where x would be determined by trial and error 3. This is the worst question I guess, and if you tell me to keep searching I understand: I find it's easy to get life cycle information (when it exists) for a species when you already know it's name, etc. But I have not found a database of larval stage characteristics of ornamental invertebrates. Could you recommend a test subject? Ideally it would be: a. cheap and common, b. externally fertilizing, c. easy to induce gamete release, d. has a planktotrophic larvae phase that lasts less than 2 weeks. <There is much known re "close" invertebrate species, but this takes a bit of familiarity, practice in "searching the literature"... I strongly encourage your visiting a large college library (of a school with a Bio./Zoology dept.), and having a Reference Librarian "show you the ropes"... Computer search bibliographies are very productive here... and a lot of fun... "Time whips by"...> Part d. is the hard one to search for. <Not too difficult as you will find> Again, thank you for your time. Your site is an incredible resource. -Tony <Glad to share. Bob Fenner>

Culturing bacteria as food 5/15/07 Hi Bob! <Peter> I'm an avid troller of WWM, and it has been an endless resource for me! Great job by you and the team helping everyone out! <A pleasure to serve, share> I've been wondering; with the advent of many techniques for culturing phytoplankton and zooplankton for the feeding of our charges, why I haven't read anything regarding the culturing of nanoplankton. <Mmm, at the hobbyist, commercial level... only a matter of time... perhaps now!> Would it not be theoretically possible (I've yet to try this myself) to use solutions containing ammonium bicarbonate, acetic acid, phosphoric acid and simple sugars for the culturing of microfungi and bacteria for the express purpose of sustaining filter feeding cnidarians, ascidians, echinoderms and annelid worms (and any other possible bacteriovores I may have missed)? <Is possible... can be done> Has this, or something similar, already been attempted? <In public aquarium, experimental institution levels, yes> How would one go about priming such a culture and maintaining it? <Could likely start such from a filtered sample of simple seawater... natural or otherwise from an established system. In the presence of extra nutrient, a lack of predators...> Perhaps with a live rock/live sand base? <Yes> How would one determine the correct feeding amounts? <Through experimentation, measuring one of the simpler components likely that a simple test kit can be used for... amending your "mix" of feeder stock to replenish...> Would you dose this into your main viewing tank using a drip method or a peristaltic pump? <Either one, or even regular measuring, and just pouring in an aliquot> Your thoughts would be greatly appreciated. -Peter <Mmm, I do encourage you to read this book by Frank Hoff (here on Amazon): http://www.amazon.com/Plankton-Culture-Manual-Frank-Hoff/dp/0966296001/ref=sr_1_1/103-2945648-4573462?ie=UTF8&s=books&qid=1179246216&sr=1-1 for input re gear, procedures...> P.S. Have your book, and hands down one of the best aquarium reads *ever*. Thanks for the contribution(s)!! <Thank you for your kind, encouraging words... and engaging prospective project! Bob Fenner>

Re: culturing bacteria as food 5/16/07 Hi Bob, <Peter> Thanks for the rapid response. I will definitely look into that reading material... I did find an interesting publication worth reading for those who might wish to attempt something similar as well. http://www.aslo.org/lo/toc/vol_45/issue_4/0789.pdf <Yes> I was actually mulling it over after I sent my last e-mail; I was trying to picture what a semi-self sustaining culture setup might look like. Assuming that the majority of bacteria we could culture fit the 100:8:0.25 CNP ratio, where any present O2 was simply fuel for reactions (as in the acetate ion portion of dissociated acetic acid), and that we can provide that ratio closely using common, affordable chemicals (much as I mentioned), <Can> would we need to provide any additional basic nutrients? <Yes... Bergey's publications is my favorite in-print resource here... but something in the way of a complete "feeder stock" solution will have to be provided> Do you need enzymatic or proteinaceous material to help bacteria replicate or are basic building blocks sufficient in their case... <These can be provided in a few ways, but are a very good idea to add on an ongoing basis, yes> I remember growing prokaryotes in a test tube in school using glucose, acid and protein... the last being the clincher, but then again that was from scratch (creationists *need* to see this happen). <Heeeeeee! Perhaps all, even "evolutionists", would be enlightened...> Would you recycle skimmer output for its organic material for bacteria "food"? <Mmm, no... too much vacillation here in terms of make-up, non-useful materials... Better/best by far to keep your/ones culture material/system axenic: http://en.wikipedia.org/wiki/Axenic> So regardless of the inputs, I imagine that at some point in the cultures life cycle, there would be sufficient new bacteria being "born" to consume all input into the system. <Yes... in a growing, going culture for sure> A 10-gallon tank, a rather large fluidized bed filter as a substrate <Worth trying, but I'd opt for a simpler sponge type... air or fluid-moving pump driven> maybe filtering directly back into the 10-gallon, along with a DSB and live rock was my main construction idea. <Mmm, again, worth trying> If the culture can reach a growth equilibrium with the inputs, than regardless of those inputs' relative toxicity to our standard charges there should be no problem in overflowing this system in the main display/fuge for feeding purposes. (i.e. if there is no longer any detectable level of NH4+ then can one assume that it is all being consumed by ever growing and dying bacteria?) <Should be fine, if not "too much, too soon" material added> Can bacteria be thought of us as being heterotrophic? <Some definitely are... though most folks consider them to be exclusively either chemo- or autotrophs> Is there any benefit to lighting the culture? <Mmm, maybe...> Does dying bacteria count towards the load on a system? <Yes... depending on what one's counting... like BOD, total nutritive value...> If we feed X amount of bacteria laden water into a main system, where only Y is being consumed, is the balance "pollution" ? <Yes, likely so to a degree> What I am hoping to discover is that our standard charges are not only bacteria hungry (ala ascidians), but also not picky eaters insofar as species of bacteria. <Some are known to be more so than others... there are many size/gradients, chemical and physical properties of this biota, as well as differential "palatability"... as you'll soon come to understand> Believe it or not, this all began with an absolute obsession of successfully maintaining Polycarpa aurata... <Ahhh! I do hope to dive with you someday... where this species is common, gorgeous... Am attaching a fave pic here, with Atriolum mixed in> Thanks again, Peter <Cheers, Bob Fenner>

Continuous rotifer drips 5/21/07 I am working on a continuous rotifer drip that recirculates. I have an approximately seven gallon salt bucket at the same height as the reef aquarium, and using an Aqualifter (Tom brand) pump to pump from the reef to the bucket, which overflows about 1/3 of the culture into the reef. I am culturing Nanochloropsis oculata in freshwater using tapwater- it's very easy to do this way for me- and I've learned that using only live algae, and waiting until the culture is completely clear before feeding again, are crucial to maintaining water quality in a continuous culture. <A good note/point> The overflow is 1 inch tubing, and I've passed airline tubing through it and connected this to a rigid tube that goes to the bottom, so the overflow essentially comes from the bottom; the culture is self cleaning. The problem I'm having is getting the rotifers to adapt to pH 8.5 and SG 1.025. <Mmm, won't do so if cultured in FW> I am using Brachionus rotundiformis as I think they will tolerate the higher temps and maybe are more salinity tolerant. <Yes... this one is euryhaline: http://www.lib.noaa.gov/korea/korean_aquaculture/zooplanktonic.htm But should be slowly adapted to culture water conditions before introduction if you expect for it/them to live for any period of time> So far I have not used a UV on the intake, being happy with whatever else grows so far. <Mmmmm> I may be successful just doing what I'm doing- and waiting for the rotifers to adapt. But, do you have any experience with a continuous drip like this, or know of any successful long term rotifer drips? Many thanks Charles Matthews <Well... the Nanochloropsis can be cultured in FW as you state, but I would take care to raise the salt content on the Brachionus... easier to care for the latter in more saline conditions... and to use (I take it for marine aquaculture in turn) as a feed stock as such. I would take more care in keeping the cultures free of other life... Bob Fenner> Re: continuous rotifer drips 5/21/07 Hi Bob <Charles, oh Chip!> An honor to get a reply from you, and thanks. Regarding my post, to clarify, I meant that I was going to culture the algae in freshwater, and use this to feed the rotifers cultured at full strength seawater. Thanks for your thoughts and will keep a watch on needing the UV Chip <Welcome... Again, I would try "mediating" the spg twixt the Nanochloropsis culture media and that of the Brachionus... Bob Fenner>

Copepod Production 5/9/08 Hi, <Hello> I have a 55 gal reef with 75 lbs of live rock that has been set up for nearly 1 yr. At first I started with a primitive filter system (a BioWheel and very cheap skimmer) while it was difficult to keep my nitrates low, I had tons of copepods. I have upgraded to a sump (sorry don't know how many gallons) a refugium (with 3" of miracle mud, live rock rubble, and macro algae) and a better quality protein skimmer. My nitrates have consistently stayed at zero for over 6 months, but I never see any copepods. <Being eaten?> I even try to look past the macro algae in the refugium and I never see anything there either. I've seeded the refugium several times with copepods, but I never see the population increase. What can I do to increase the pod population. I am asking because I want to eventually keep a Mandarin Dragonet, but want to make sure that I can supply his needs by increasing the pod population in my display tank and by culturing them in a stand alone. Many thanks for your assistance. <You're welcome and do read here and related FAQ's/articles below text. http://www.wetwebmedia.com/ca/volume_2/cav2i1/Pods/pods.htm James (Salty Dog)>

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