Culturing a food chain

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shawngibson
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Culturing a food chain

#1 Post by shawngibson » Thu Oct 22, 2015 12:40 am

Probably one of the strangest questions ever asked.

Is it possible (with a limited individual's budget, no lab, living in a large apartment) to create a basically self-sustaining system, in an aquarium, or several aquariums, where you start with, say, algae or coral and maybe an autotroph of some sort, then move up to a single celled prokaryote, then say a copepod or artemia, then a small (~1") fish?

So in other words, in a basically self-contained system, species 1 feeds off light and minerals, species 2 feeds off species 1, species 3 feeds off species 2, etc. up to the size of a very small chordate.

I'd like to be able to study and photograph all of the variations I can see/find within a very small group of creatures. And by 'self-sustaining' I mean obviously with some human work, i.e. cleaning/maintenance.

Shawn

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Re: Culturing a food chain

#2 Post by charlie g » Thu Oct 22, 2015 2:10 am

Yes, yes...it has been a wonderful activity for centuries! We have the : terrariums, the aquariums, the vivariums since Roman times..probably earlier in China and meso-america.

You need to respect the local you reside in...if you keep your 'world in a bottle' outdoors. If you totally keep your system indoors..it is up to you to set the 'daily cycles/ the seasonal cycles/...and the assemblage of 'autotrophs' and 'heterotrophs' and 'saprotrophs' ( a food chain...nore clearly termed a: food web/ trophic levels sustainable system).


Biosphere II closed down a while back...it is hoped to be a sort of educational park with houseing the last I heard on public radio.

I suggest you take a five (5) gallon cheap fish tank...that is: aquarium tank ( as it holds water if it's used for water...rather than growing crickets or meal worms, etc. .). Start a system...think: primary producers(autotrophs), think location of that tank for natural light cycle, think heterotrophs ( cheap guppy fish to start), think snails and outdoor water collected rock and gravel ( to suppy the saprotrophs). These setups are a joy to visit each day..perhaps to sample for microscopy. all the best, charlie guevara

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Re: Culturing a food chain

#3 Post by gekko » Thu Oct 22, 2015 1:53 pm

I don't know enough to give advice, other that to say that charlie g knows exactly what he is talking about.

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Re: Culturing a food chain

#4 Post by shawngibson » Thu Oct 22, 2015 3:12 pm

Thanks Charlie, lots of useful information there:)

I guess my first stop will be a knowledgeable fish/aquarium store. Fortunately there is one several blocks from my home:)

I suppose starting with Artemia makes sense for me, since I find them fascinating under the microscope (though I can't get them to live longer than 3 days in a small glass container...apparently they need specific conditions to grow to adulthood including proper salinity, light, temperature, aeration and water movement). And they apparently eat cyanobacteria, diatomes and adults seem to be best fed on Dunaliella veridis:

http://learn.genetics.utah.edu/content/ ... ne_shrimp/

So I guess I need to find me some diatomes and Dunaliella veridis and figure out what sustains them, too:)

Starting to feel like a mad scientist...

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Re: Culturing a food chain

#5 Post by shawngibson » Thu Oct 22, 2015 3:39 pm

From the same website:

http://learn.genetics.utah.edu/content/gsl/foodweb/

Interesting. I wonder if I could create a less salty variation of this environment that would allow the top feeder to be something like a small guppy, as Charles suggests. Seems a very salty system...

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Re: Culturing a food chain

#6 Post by DaveH » Thu Oct 22, 2015 7:13 pm

shawngibson wrote:Thanks Charlie, lots of useful information there:)

I guess my first stop will be a knowledgeable fish/aquarium store. Fortunately there is one several blocks from my home:)

I suppose starting with Artemia makes sense for me, since I find them fascinating under the microscope (though I can't get them to live longer than 3 days in a small glass container...apparently they need specific conditions to grow to adulthood including proper salinity, light, temperature, aeration and water movement). And they apparently eat cyanobacteria, diatomes and adults seem to be best fed on Dunaliella veridis:

http://learn.genetics.utah.edu/content/ ... ne_shrimp/

So I guess I need to find me some diatomes and Dunaliella veridis and figure out what sustains them, too:)

Starting to feel like a mad scientist...
Hi I did write a long post but seem to have lost it somewhere in the abiss!
Probably the easiest food for brine shrimp is spirulina you can buy 25g for less then £2.00 and it will last ages, put a very small amount in with the eggs at the start and then don't feed until the third day, brine shrimp don't feed until the 2nd or 3rd day. I have kept a small jar of shrimp going non stop for 4 or 5 years in the past.

If you search diy bio sphere you may find some useful information regarding making a food chain, fresh water will easier than marine.

Dave

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Re: Culturing a food chain

#7 Post by shawngibson » Thu Oct 22, 2015 7:18 pm

Excellent, thanks Dave.

>>fresh water will easier than marine

I find this confusing. I'd much prefer non-marine species (because of the fish, i.e. not crazy expensive or exotic, I just want little guppies or such) but the brine shrimp require a salt water environment. I'm confused...

I'll start Googling DIY biosphere:)

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Re: Culturing a food chain

#8 Post by actinophrys » Thu Oct 22, 2015 7:23 pm

I'd like to offer my thoughts as someone who keeps a freshwater aquarium, which does have fish that eat different things though I do have to add flakes and pellets. I think it should be possible to keep some small fish in a self-contained aquarium if it is large enough and well-lit, but it would be tricky to balance and you should stay ready to intervene.

A first concern, before food even, is that while for instance pulmonate snails can be kept in the same water for months, fish are really sensitive to wastes like nitrate and ammonia. That's why most aquaria need a charcoal filter and regular water changes. But nitrate is converted to ammonia by bacteria that live in gravel or sediment, and that in turn can also taken up by fast-growing plants, which I assume is what you want here so the nitrogen stays in the ecosystem. I don't know if anything is available for marine tanks; I've read seaweeds can be prone to rapidly dying so making things much worse.

For freshwater though I can suggest trying duckweed (Lemna), which is also hardy, isn't destroyed by snails, and provides a refuge for small animals. My 250 L is covered by it and I expect it would easily keep things clean for some small fish. I'm skeptical that a 5 gallon would be enough. In any case, if you experiment please be sure to do regular checks for ammonia, and ready to add a filter if there is impending disaster; here many pet shops will do water tests for free.

That aside, it genuinely isn't common to be able to keep a fish long without feeding it. People sometimes assume you can with algae eaters like plecos, but you really aren't supposed to. I've seen loaches go for months without coming out during feeding, so presumably living mainly off snails, but I imagine they were also scavenging the odd bit of food other fish missed and either way those are why there were snails. In any case, though, nothing of that sort count as the small fish you were asking about.

The problem is that while in nature things like guppies sustain themselves off little arthropods and worms, you can't usually keep them closed together without the population getting destroyed. I am sure that could be circumvented in a large enough tank with lots of refuges for them, but I don't know how big that would have to be. I think it is only sensible to say, though, that you would want to have as many types as possible, since each can exploit different parts of your aquaria, and varied nutrition is a good thing anyway.

For instance Daphnia are a common live food without the special requirements of brine shrimp, but are filter feeders, and normally culturing them in numbers requires water that has become green. Most fish only eat the smallest snails, but that could still help, since they are hardy, breed quickly, and can feed off things like algae films. Floating plants provide habitats for mites and copepods from some source or other, which I know is at least a help to baby fish. Take enough together and you might get a sustainable food supply.

Again, I would want to keep a close watch, and if the fish aren't finding anything have flakes ready. Because the nice thing about this experiment is that if you aren't able to make a closed ecosystem, you can still fail into a normal aquarium. Which in at least my judgment is both nice to have and still a good source of material for the microscope.
Last edited by actinophrys on Thu Oct 22, 2015 7:30 pm, edited 2 times in total.

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Re: Culturing a food chain

#9 Post by DaveH » Thu Oct 22, 2015 7:28 pm

shawngibson wrote:Excellent, thanks Dave.

>>fresh water will easier than marine

I find this confusing. I'd much prefer non-marine species (because of the fish, i.e. not crazy expensive or exotic, I just want little guppies or such) but the brine shrimp require a salt water environment. I'm confused...

I'll start Googling DIY biosphere:)
Not to get confused I thought the brine shrimp and the biosphere were different projects.

Dave

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Re: Culturing a food chain

#10 Post by shawngibson » Thu Oct 22, 2015 7:39 pm

Dave - Ah, that makes sense:)

actinophrys - I am going to read your post thoroughly (a few times probably!) when I get home. But right now I see it's clear I need Daphnia, not Artemia, if there is any chance to have this be self-sustaining. In fact, it might be best to raise them both (Daphnia and Artemia) in separate tanks for use a food to be transferred in manually to feed the fish.

For the fish tank, I plan on buying a 20 gallon aquarium.

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Re: Culturing a food chain

#11 Post by DaveH » Thu Oct 22, 2015 7:47 pm

You can grow brine shrimp to adulthood in as little as 500ml of water it all depends how many you want, just a few to study or a supply to give your fish a treat. I have kept brine shrimp as pets and kept a small culture alive for 4 to 5 years in the past. Using a setup similar to sea monkeys.

Dave

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Re: Culturing a food chain

#12 Post by shawngibson » Thu Oct 22, 2015 7:52 pm

Thanks Dave. Where do you buy spirulina...a fish/pet store? I have lots of 250ml Mason jars that can be used for this purpose.

Obviously, this project is going to take some time and a lot of learning:)

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Re: Culturing a food chain

#13 Post by DaveH » Thu Oct 22, 2015 9:12 pm

You can get 25gms on eBay for £1.79, but you should be able to get it in a good pet shop or a health food shop, is a blue green algae in the form of a green powder. In a 250ml jar only use a very small amount use a cocktail stick like a shovel one only use 3 or 4 mm of the cocktail stick if that makes sense.

Dave

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Re: Culturing a food chain

#14 Post by shawngibson » Thu Oct 22, 2015 10:45 pm

Thanks Dave. Went to the local pet store, and they didn't have spirulina, but they did have an algae product that was spirulina and kelp (and some vitamins and other chemically worded ingredients), so I grabbed that at the salesperson's suggestion. Also bought aquarium salt, but upon getting home I see it says for freshwater fish and it doesn't dissolve. So I put a pinch (1/4 teaspoon approx.) of sea salt in about 200ml of water and boiled it for 3 minutes. Will let that sit 24 hours and put some brine shrimp in tomorrow night. Since they are apparently bottom feeders I suspect it's better to find a light source that shines underneath the Mason jar? I seem to recall reading a top-source leaves them constantly stressing as they struggle to get to and stay at the top?

The person at the store, after I told him what I was hoping to do, said I should start (when I buy an aquarium) by creating an environment with bacteria, and build up from there.

One thing I noticed, in all of the aquariums with many different types of fish, is that I didn't see a single juvenile. Is it not possible to keep juveniles in a closure with adults? I suppose that is a species-specific question... I'm sure a lot of carnivorous species are just as apt to be cannibals as not lol.

This is much more involved than raising cats. Seriously lol.

Shawn

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Re: Culturing a food chain

#15 Post by actinophrys » Fri Oct 23, 2015 3:28 am

Most fish will eat any tiny fry, although there are exceptions like strict herbivores or types that look after their young. What you see in pet stores, though, generally are only juveniles and can be expected to get at least 2-3 times larger.

There are lots of community fish where they do get along with adults. In some more aggressive types little ones can get harassed or worse, but in others they can actually get along even better than adults do with each other, since they aren't in direct competition.

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Re: Culturing a food chain

#16 Post by shawngibson » Fri Oct 23, 2015 3:32 am

Ah, I see. Thanks. Can you recommend a fish that gets no bigger than approx. 1.5" and can hang out with many others of its species?

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Re: Culturing a food chain

#17 Post by actinophrys » Fri Oct 23, 2015 5:02 am

That's a pretty small limit! Guppies for instance are small, friendly, and easy to keep (and breed) though they do prefer some aquarium salt, but even there the females can grow to 2½" long.

A few characins do match your size, including cardinal tetras, neon tetras, and dwarf pencilfish; and among bottom-feeders there are dwarf and pygmy corydoras. All of these are tropical schooling fish, so actually need to be kept in groups. There are also dwarf puffers, which are good with their own species if they have hiding spots and eat shelled animals like snails.

However, I haven't kept any of these particular species and can't say how suitable they would be for a beginning aquarium, let alone your project; some quick searching for instance suggests dwarf puffers need things kept particularly clean. I'm sure you can find a dealer or hobbyist who knows much more than I do.

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Re: Culturing a food chain

#18 Post by DaveH » Fri Oct 23, 2015 10:18 am

Cats take a lot more time and are harder I have 4.

The salt content is important the sg should be 1.018 or very close, but as a thumb rule 25gms per Lr should do if you have some baking soda in the kitchen cupboard then a very small pinch in your jar will be beneficial as a ph buffer. The aquarium salt is fine I have used it dissolve it in hot water. Don't use table salt it won't work, I have also used sea salt from the supermarket. If the food you have is not powder then crush it up fine between two tea spoons, brine shrimp are filter feeders. In 250mm jar you should be able to sustain 3 or 4 adult brine shrimp, just stand the jar somewhere light and warm, the population will settle at a level that suites both the container size and the food supply, to little food and the population will decline a bit and to much food and the population will become extinct!
Just give the water a stir every day or when you think about it and feed them once a week or so.
When the jar settles down and you get algae growing on the sides it will almost look after itself just keep the water topped up and feed with a tiny bit of food from time to time, you should have shrimp in various stages of development.
If this project takes your life over and want to get a hydrometer the look in the home brew shops there a lot cheaper then the pet stores I obtained my one from Wilkinsons.

Dave

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Re: Culturing a food chain

#19 Post by Peter » Fri Oct 23, 2015 6:04 pm

Hi Shaun,
I think you may need to have a good hard look at the basics . In the environment every carnivore needs to have at least 10 times its mass in herbivores to feed on and every herbivore needs to have at least 10 times its mass in vegetation feet on. So if you intend to have say 10 g of carnivore in your aquarium then you will need at least 100 g of herbivore and for them at least 1 kg of vegetation e.g. algae. Even in a 5 gallon aquarium 1 kg of algae, if it's free-floating, will make the water quite murky, and will need a lot of light, and consume a fair amount of dissolved minerals.
Hope this helps.
Peter.

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Re: Culturing a food chain

#20 Post by shawngibson » Sat Oct 24, 2015 2:10 am

Thanks everyone. OK, between complexity and further complexity, I'm going to dumb this down so that I might have some chance at success. I think I need 3 tanks:

1) 5 gallon tank for raising adult Artemia to study, and also prove a food source for (3)
2) Ditto with Daphnia
3) 20 gallon for raising what appear to be great breeders and not very challenging (and small!) fish, i.e. Poecilia wingei:

http://www.petsolutions.com/C/Live-Fres ... -male.aspx

I'll create 3 separate environments conducive to each of the 3 species, i.e. tank conditions, food, etc, up to the Endlers, which will eat mostly brine shrimp and water fleas.

Appropriate microbes for each, settings, temps and other conditions, and for the Endlers, a trap for fry so they don't get eaten...or do, depending on if I want to look at life cycles through my microscope.

Does this make more sense?

Shawn

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Re: Culturing a food chain

#21 Post by DaveH » Wed Oct 28, 2015 8:12 pm

Sounds like it's getting complicated, turning into a major project. Did you keep the shrimp alive in the jar I might start some off next week.

Dave

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Re: Culturing a food chain

#22 Post by shawngibson » Wed Oct 28, 2015 11:12 pm

Artemia are doing great thanks to you. I followed your instructions.

I just took some photos, will post after processing them:)

Shawn

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Re: Culturing a food chain

#23 Post by shawngibson » Thu Oct 29, 2015 12:44 am

Shined a light and caught a few; put them on a slide.

They are very fast. I couldn't photograph them. I added glycerin (a lot of glycerin); then some alcohol, but they were still too fast to photograph.

Then they died I suppose because of the alcohol. I got a few photos, but I was hoping to put them back into the jar...I suppose the only way to capture the anatomy of them is to kill them. Blah.
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Re: Culturing a food chain

#24 Post by charlie g » Thu Oct 29, 2015 4:37 am

Please purchase low cost: 1.5% methylcellulose...it is a viscosity tool to 'slow down' rapid moveing organisms.

It permits image captures of all sorts of rapid moveing organisms. charlie guevara

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Re: Culturing a food chain

#25 Post by shawngibson » Thu Oct 29, 2015 12:54 pm

Thanks Charlie, will do. If I were to, say, use a fine mesh net and rinse them in reserved saltwater after putting them in this, would it be ok to put them back in with the rest?

I don't really like the idea of killing them just to get good photographs. Obviously if I want to permanently mount them, that's different.

I have a slide with an approx. 2mm rubber grommet that I glued to the slide with acrylic (clear gesso actually) so I can get some 'depth' of water and create images of the Artemia in 3 dimensional space.

Shawn

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Re: Culturing a food chain

#26 Post by shawngibson » Thu Oct 29, 2015 12:56 pm

Peter wrote:Hi Shaun,
I think you may need to have a good hard look at the basics . In the environment every carnivore needs to have at least 10 times its mass in herbivores to feed on and every herbivore needs to have at least 10 times its mass in vegetation feet on. So if you intend to have say 10 g of carnivore in your aquarium then you will need at least 100 g of herbivore and for them at least 1 kg of vegetation e.g. algae. Even in a 5 gallon aquarium 1 kg of algae, if it's free-floating, will make the water quite murky, and will need a lot of light, and consume a fair amount of dissolved minerals.
Hope this helps.
Peter.
I keep meaning to reply to this. If the top of the food chain in a 20 gallon aquarium was either Daphnia or Artemia, would this be feasible?

Shawn

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Re: Culturing a food chain

#27 Post by shawngibson » Thu Oct 29, 2015 10:44 pm

I just purchased a small aquarium kit to get started. I am getting (locally) a batch of live zooplankton, and (dead) phytoplankton which will feed both the zooplankton and the Artemia. He is suggesting a salinity of 1.19. That's quite a lot higher than Dave's suggestion.

I also keep reading 1/2 cup aquarium salt per gallon of water?

The measurements on the salt I have (from API) are for freshwater fish.

I bought a hydrometer based on some Googling.

Zooplankton is (32oz):

50% Tisbe copepods
Acartia copepods
Parvocalanus copepods
Pseudodiaptomus coeppods
Tigriopus (Tiger)
Rotifers
Moina Salina
Nannochloropsis Phytoplankton
Tetraselmis Phytoplankton

Rotifers are (16oz): L/S types

Phytoplankton is: nanno sp. and tet sp

Hopefully someone will chime in on this, I'm a bit lost lol.

Shawn

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Re: Culturing a food chain

#28 Post by DaveH » Fri Oct 30, 2015 10:03 am

Hi brine shrimp live in the salt lakes where the sg is constantly changing, the completely dri up at one point in the cycle, so they have to be pretty hardy. As the sg increases the shrimp breed faster as they know there fate. So I would set the sg at a level that suites the other inhabitants and the shrimp will be fine. Don't get confused with the information on the net regarding rearing brine shrimp for fish food, a teaspoon of eggs in a tank with an air supply, keeping the water cloudy with food to grow them on, that level of shrimp will decimate your environment in no time. If you read the Make Magazine project on there biosphere it shows the food chain and the scale of each steep, I think it's the best set of instructions on the net. The half cup of salt per gallon is probably the rate for treating fresh water fish as I think you have aquarium salt. You might like to consider using marine aquarium salt as it contains other additives but the cost starts to increase quite a bit.

Ps brine shrimp will live in water with between 1% and 5% salt.

Dave

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Re: Culturing a food chain

#29 Post by shawngibson » Fri Oct 30, 2015 12:45 pm

The Make Magazine project is fascinating, thanks:) Once it warms up (averaging around 0-10C here in Toronto right now, and I assume that means little in the way of critters) I have a stream right across the street...so come May or so, I'll definitely do this project.

What you mention is exactly the problem I'm having - very little info on the net about breeding brine shrimp, and indeed there are billions of articles on 'breeding' brine shrimp that have absolutely nothing to do with breeding, merely concentrating on growing them quickly for use as a food source.

According to this guy:

http://www.instructables.com/id/How-to-Make-Sea-Salt/

...at least in some areas actual marine water is circa 3.5% sea salt.

According to this site:

http://www.drsfostersmith.com/product/p ... catid=4982

What I have is actually evaporated sea salt, so I should, I would think, be able to start with 3.5% salt, or say 3% just in case, and dial it in from there. I suppose I can boil say 1 liter of water with 1 cup of salt and use that as a concentrate? To measure the salinity, I have this:

https://www.bigalspets.ca/living-sea-hy ... ter-8.html

And I will use distilled water which I can buffer (if that's the right term) with "Prime".

If any of this sounds wrong, please say:)

Shawn

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Re: Culturing a food chain

#30 Post by DaveH » Fri Oct 30, 2015 6:44 pm

Hi Shawn

With regards to the Artemia I think you may be looking at it from the wrong angle, I don't think you are wanting to breed large volumes the shrimp will just naturally breed if conditions are more or less right.
You will see them mating and the first three broods for want of a better word will hatch inside the female and be born live, after that the female will lay persistent eggs that have to be dehydrated once or more in order to hatch this protects the species.

Low salt content will produce shrimp that mature later grow bigger and have longer tails, just think start of the season.

High salt content will produce shrimp that mature quicker are smaller and have shorter tails and will probably only produce persistent eggs, just think end of the season (the end is nigh).

Although there are more than one species of Artemia shrimp that migrated to water with a lower salt content were thought to be a different species, until they were observed migrating back to water with a lower salt content and reverting back to there former format.

There is a train of thought that 3.5% is the best level of salt to keep Artemia as pets, this should provide a continuous culture and shrimp will mature in 18 to 21 days at 20 C

As you can see nothing is set in stone and most parameters are fluid I hope this is of some help.

Dave

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