Protozoa farm

[Dembowski]

I’m very interested in protozoa but do not live near a pond. Besides, in the winters of western Pennsylvania, everything is frozen anyway. I’ve tried my hand at small infusions of rotting vegetation, but I’m looking for something a little more “permanent”. Can anybody tell me, or guide me to a place on the Internet that will tell me, how to set up and maintain my own source of protozoa in, say, a 10 gallon aquarium?

I have no problem starting with a protozoa culture as sold by some place like Ward’s … but please keep in mind that I do not live near a pond so that I cannot “start with a bucket of pond water”. Thanks.

[Steve West]

Hi Bill,

I use a 5 gallon aquarium free of fish. I turned off the water circulation so it's standing water. I also have a light on a timer to help encourage algae growth. To "seed" it, I dump all my samples I collect elsewhere into it (gunk and all). The surface has a health crop of duckweek growing. There are lots of snails and freshwater shrimp that have established themselves.

I tend to think that the 5 gal aquarium is too deep as I have to stick my arm into the water to get the eyedropper near the bottom.

Steve

[gpmatthews]

As Steve says, add any samples you may acquire to the aquarium. you can include soil samples, small amounts of vegetation, samples of standing water, such as puddles, or other rainwater you may be able to collect, including anything frozen, scrapings from gutters, drains etc. If you have friends who keep fish, try some samples of water and sediment from their aquarium. Sample sizes need not be buckets full - just a few ml is quite sufficient.

Always keep a few small sample jars in your jacket pocket - then you can take samples whenever you see anything interesting.

If you need to start off using tap water for volume, leave it to stand a week or so before adding samples.

[Ken Ramos]

Some good information here on culturing protists. Steve, how do you maintain an adaquate DO level in the aquarium with out circulation or aireation? Or does the duckweed maintain a satisfactory DO? Inquiring minds want to know. I am going to start one this spring when the creek temps here in the mountains begin to rise and more life forms start to become active in them.

[Steve West]

Ken,

I can't maintain it if I don't know what it is!! What is DO?

[S. Alden]

Ken,

I can't maintain it if I don't know what it is!! What is DO?

I believe Ken is referring to Dissolved Oxygen.

[Dembowski]

Thanks for all of the above. Where is the ideal place to keep the aquarium? Right now I’m thinking about a work table in my home-office that is in front of a north-facing window. That would give me good sunlight, but not direct sunlight, during the day. That sounds good to me on paper, but is that suitable for what we are talking about? Just for the record, I have no problem with growing some algae in the process.

Also, how important is the surface area of the water? Am I better off with a half-full 10-gallon tank to get the surface area or a full 5 gallon tank? It seems that the larger the surface area the greater the rate of evaporation but the better exchange of gases. I would think that a goldfish bowl (small opening compared to volume) would be out of the question but perhaps I'm wrong and it would be better.

[Kenv]

Hi Bill, I think it would be a great idea to start a water tank. If you do be aware that many local authorities add chlorine to domestic water supplies to kill any protozoa and bacteria that may be present. If you go to a shop which supplies aquarium fish you can purchase a small bottle of liquid which neutralizes the cholorine. I think leaving the water for two or three weeks before using it does the same job but I'm not sure.
Kenv

[Dembowski]

I don’t think that my problem will be getting good water to fill the tank. I live in an area where rain and/or snow-melt runs within easy walking distance. It may, in fact, prove to be a minor source of critters in itself. I guess my big question is what to place in the bottom of the tank; sand, dirt, foliage, stones, wood, or nothing. And how about obtaining some water plants from a garden supply or pet supply store? Does that bring the risk of adding some creatures that might decimate the protozoan population? I hate to make a big deal out of this, but if I can draw on your collective experience I might be able to save myself some heartburn.

[lacerta]

Hi Bill, Not much experience here culturing protista, but I do know from my limited laboratory experience as a student that most of these critters are found in places you would least expect. You mentioned aquatic plants. Now, there is a innoculating source for all sorts of protozoa! A few pond plants from a nursury or tropical fish store should provide ameboids, hydra, ciliates that like to attach to plant material such as Vorticella and Stentor. Many forms of nitrogen fixing cyanobacteria live symbiotically with aquatic plants. Especially on the underside of duckweek and other floating types. I would use gravel or river rocks as a substrate. To make it simple, any rooted type plants should be kept in their pots instead of trying to root them in your tank. Just submerge them in their pots and weight down with rock or gravel. Go easy on the duckweed. It can overtake a tank fast and will shade out anything underneath. Remember that plants require light. Indirect lighting should be fine for some species but some like it intense. With no active filtration, go easy on the total bioload to prevent the whole thing from turning septic. Start off slow and allow the nitrogen cycle to establish itself. It won't take long before the tank bottom will develop its own "mulm" of detritus rich with stabilizing anaerobic bacteria (hopefully). After a few weeks the tank should provide a source for all sorts of neat bugs. Not just protozoas but different types of algae, nematode worms, rotifers and other multicellular forms.
I have a paludarium setup that houses poison arrow frogs. It is heavily planted with tropical ferns, bromiliads, and tropical java moss. The water portion of the tank is only about 3 inches deep. It is being recirculated with a small submersible pump that draws the water through a hydroponic clay substrate. The 3 guppies that live in the water have never been fed. Apparently they are subsisting off the algae and small creatures that live in the water. The entire system is lighted with compact flourescent lights on timer. It is a mini-ecosystem. All I do is feed the frogs wingless fruit flies. The frog droppings percolate through the substrate from frequent misting and the plants go wild from the nitrates. What the guppies are subsisting off of I hope to find out when I get my new 'scope. Check out the following website for ideas in setting up a living vivarium or paludarium: www.blackjungle.com
George

[Ken Ramos]

Sorry Steve Sue is right. I am referring to Dissolved Oxygen. I have always noticed that if you happen to have a small bubble in a wet mount, there is always a congregation of protozoa around this bubble. I read somewhere that they are attracted by the oxygen level existing there.

[Steve West]

I don't do anything, but let the water stand. Maybe I should turn the water recirculator back on?

It would be a fun experiment. Set up two identical 5 gal tanks. One with a recirculator, one not. Fill them up with the same water, always dump half of the contents of collections jars into each. Observe which protozoa like each environment.

I notice above that people are worried about maintaining water levels with tap water. I usually take a gallon jub with me and fill it at the collection site. I use this water to top off the tank.

Steve

[Kenv]

You could also get some Oxygen Weed from your local aquarium shop.
Kenv

[Ken Ramos]

Huh! Two excellent ideas. It would be interesting Steve to see which actually does better and what species of organisms develop in an oxygen rich environment and what prefers a stagnant one. I know ameba thrive in warm stagnant waters so be on the look out for BSL2 (Biological Safety Level 2) organisms. Yeah I know, I'm at it again.

[Steve West]

Well, Ken, you know I was taking a lot of amoeba pictures a few weeks ago. They are all over that tank and lots of different kinds. I know you are in to the biological hazard stuff Mr. Professor:)

I like living dangerously, and apparently so does my 5 year old since he's always digging around in that tank and pulling out larger stuff for the old AO 570 stereo stand.

Steve