There must be some aquatic insects that would work as well.Update 9/17/00: I have 4 new bottles going, capped on 8/28/00. I read that brine shrimp reproduction is very dependant on the salinity of the water... so my 4 new biospheres have salinities of 1X, 1.5X, 2.5X, amd 4X normal ocean salinity. Check the Homemade Biosphere link below for more information
An ecosphere, or biosphere, is a completely enclosed airtight container that has living things inside. Since the container is enclosed, the living things will only stay living if they are in a sustainable state.
It is easy to do this with water and algae, but algae isn't all that
exciting to watch. If some kind of animal is included, it adds a great deal
of visual interest. Brine shrimp are typical. Snails are another possibility.
There must be some aquatic insects that would work as well.
So, I gathered some brine shrimp eggs, algae, fresh water, dehydrated sea water (I purchased some Instant Ocean at a pet store), and a Sea Monkey kit, and started playing. I used 2-liter Pepsi bottles and 40-oz Miller Beer bottles (I had to drink the beer... uh... for scientific reasons) - with caps - to hold my purported biospheres. One of the problems with trying to create a biosphere is a lack of feedback - when a biosphere dies, I'm often not sure why. Also, one of Murphy's Laws is always in play: Under the most carefully controlled conditions of light, heat, humidity, food supply, and environment, the organism will do as it damn well pleases.
My first several biospheres were failures, and I'm pretty sure it was because of a lack of oxygen. But now, I'm producing ones that can last for at least a few weeks. My current longest-lived one was made on 10/27/98, and shows no signs of dying any time soon.
Here's what works for me:
* 2-liter soda bottles work very well
* Make a liter of salt water at 1/2 - 2/3 strength. Add a scoop or two of the algae that comes with the Sea Monkey kit (the scoop also comes with the kit). Let this sit in a light place for a couple of weeks - even occasional direct sunlight is OK. You should see an algae sediment forming at the bottom of the bottle. On one of my test bottles (my best one), I got a good green layer of algae on the bottom. Once you get this, you're in bidness, you can "clone" as much as you need.However, I don't think it is necessary to get the deep-green algae. My current longest-living bottle (alive since 10/27/98. OK, not all that long... but it's the best data I have) has a very pale algae in it, with little trace of the deep green - although lately (12/23/98) a dark greenish patch has been growing in there as well. Giving the algae a good start is the key to a successful biosphere - having patience during this step is crucial.
* After you have some good algae, in a separate bottle, start some brine shrimp eggs + more 2/3 strength salt water. Give them 1 scoop of Sea Monkey food (or a ration of algae) every week to 10 days. Aerate the bottle every few days (blow thru a straw, pour it back-and-forth into another container, etc) to keep the oxygen supply up.
* After 3 weeks, you hopefully have some brine shrimp that are approaching 1/4" in size, and some algae sediment. Add the shrimp to the algae bottle (5-7 shrimp are ideal, but it can be hard to control the number while pouring) and screw the cap on tight. The bottle should sit in a light place, but not in direct sunlight.
* It's good to make 2 identical bottles at the same time: One to leave covered at all times, and one that is opened occasionally for subsequent cloning if the biosphere is sucessful.
* If you get a sucessful bottle, you can try "cloning" it:
Pour some of it into a 1/2 - 2/3 strength salt-water solution, and replace
the lost volume with plain salt-water. Cloning resets the "born-on"
dating, but doesn't seem to have any real effect.
* If you get a good-looking algae culture going, you can try making a biosphere like this: Put a liter of algae-salt-water in a new, clean container. Add about 10 brine shrimp eggs. Close - it should turn into a sucessful biosphere in a couple of weeks. The difficulty here is in adding only 10 eggs, they are *tiny*, and it is easy to add several hundred. I estimate that the $3 vial of eggs I got from the aquarium shop has close to 100,000 eggs in it.
Here's pics of my best 2 bottles (the one on the right was capped on 10/27/98, the one on the left was capped on 11/27/98, and opened on 12/8 for cloning), and a lame close-up of a shrimp taken with a digital camera - lower right of picture. Above is a picture of a shrimp that I took with my scanner - I put the shrimp right on the glass (with a few drops of water), blotted the excess water away, and then scanned it at 600 ppi while shining a flashlight on it.Backlighting it with a flashlight turned out to be crucial in getting some detail in the body.
That's it!
For visual interest, you can add some colored aquarium rocks on the bottom, a couple of shells, and a floating salt-water plant. It is possible that I'll eventually need to add a snail or some kind of scavenger to clean up the shrimp poop - so far, I haven't worried about that, we'll see if it becomes a problem.
If you make your own sucessful biosphere, send me email and tell me about it!
I have found that a 1-page form is handy for recording results. Here is an HTML example, and here is one in Microsoft Word format. I recommend you copy one of these documents for your own use - and again, I'd be interested to see your results.