Biology Experiment Questions
Francisca Noggles
Hello all!
I'm currently in a biology class and have the opportunity to conduct an independent research project or experiment for an assignment, it does NOT have to be complicated or extremely in depth.
Examples: What is the best form of ammonia/waste to use to cycle an aquarium? Does the temperature of the water affect the basking frequency of aquatic turtles? How does gravel depth affect the growth of [some plant]?
Basically, a question where I can isolate a variable and gauge the animal's/plant's response to changes in that variable. And also preferably something that won't take more than a month or two to gather data.
My favorite biology project ever was testing to see where on drinking fountains had the most bacteria and what cleaners worked best (result--the buttons are BY FAR the dirtiest and don't drink out of the drinking fountains near the cafeteria!). If I wanted to aquarium-ize that experiment, I'd think about maybe swabbing and figuring out where most bacteria grow in a tank--are all surfaces colonized evenly? Do plants affect it? Substrate type? Filter? Lights?
I'd set up identical 5 or 10-gallon tanks (or plastic tote bins), then get some inexpensive plants that are easy to compare (maybe windlov ferns or java moss that can be weighed out?). Some get x amount of living plant material, some get 2x, some get 4x, and one gets none as a control. Pour in the same amount of (dechlorinated) water and add a (small, measured) amount of ammonia. Get out a test kit and see how long it takes each tank to process. Repeat regularly to see how they progress over time.
An easy one but also one I have wondered about, ammonia clearance rates. You can use small aquariums and reuse them, plus this should only take a day or two. What clears ammonia quickest? Plants only, cycled sponge filter, air stone, activated carbon filter? Take a pre measured amount of ammonia dump it into the control aquarium and measure the ppm. Then in the test aquariums dump same amount and measure ppm every hour or so until it is gone. You can then keep using the same tanks and see if a sponge filter and plants work better than activated carbon filter with an air stone and so on.
Heck yes to fun and simple!! Maybe I could do something similar with my turtle... although he can be a little dumb...so my hypothesis will be an easy one to make ? but the results would be interesting all the same! Plus I could probably make a video out of it...hmmmm
But I actually do like this one and would be curious to see the effects. The shorter photoperiod might affect the fish too... (although if it were an experiment we probably wouldn't have fish to avoid that variable affecting growth. haha!)
You could try an experiment on methods of cycling a tank: fishless using ammonia (one with and one without plants) versus a light fish load (with and without plants). In lieu of plants (or to change/add variables), you could include tanks with different pH, hardness, temperature, daily light, etc. Whatever you do, I hope you'll share the results here!
To keep it simple but interesting maybe see if you can get a fast growing plant that is grown out of water and work out the conditions they more quickly convert to aquatic form. Like maybe a sword plant for example. Could simply use any Glass vessel. Same room (for temperature concistency) buy 3 of them do one in artificial light one in natural light and one with no light. (No light would be control) (repeating it with 3 times for each would be a reliable experiment but if not the end of the world if it's not as imperative)
IMO an experiment with a snail colony would be a good for a month or two experiment. Isolate a variable like food, substrate, or water additives ect. Then you can measure their shells before and after for growth rates and number of snails and eggs for reproduction rates. If you have or can get a bunch of "pest" snails you'll have plenty of data points to worth with for charts ect and snails grow and breed fast enough for it to be measurable in one or two months.
I would agree with @TheDuke about the plant issues that it can be difficult if you only use a single plant per tank. but I will say with experience animals can be incredibly difficult if they run into any issues also. It's part of the problem with any experiment!
Let's say you natural light one died? You can write multiple reasons and do a tonne of research! Was it a natural variable? Genetic? Did algae out compete? Did it grow more roots rather then leaves? Even though it's less growth is it "healthier?"
Not to mention this is why you repeat an experiment 3 times or more times to give you an "Average" (mean) of a population sample (obviously more is better but 3 is more than sufficient for what you need) so if one test they die but the other 2 times it works its okay! You still have an average and you get to try to explain why it happened you don't have to have the right answer just show you understand there is reasons it did happen!
The old circus/TV adage of "don't work with children OR animals" is very true it can be even more complicated to get results on animals as their is a lot of little variables and sometimes animals will do much the opposite you intend. Or possess another variable you can't control.
Just when you write up about it definantly make sure to address any of the issues you face (flora or fauna) and possible reasons why. Presenting plausible and realistic reasons as to why something didn't go as intended is exactly what science is built on!
Don't forget though (it may or may not matter) but it's not just good to have a few samples per "experiment" but also to repeat that whole experiment 3 times. This helps mitigate the "control error" of an experiment.
For example if you have snails in 3 seperate tanks and you finish up with one tank doing well for population and another 2 did bad. How can you clearly say it wasn't something in the fish tank silicone of those 2 tanks that's caused the problem or a spray that fell in, or that you didn't clean it properly before use etc etc? (You can't!) Therefore if you randomise the tanks another 2 times and the same happens each time you can say with certainty the tank had no effect and it was the treatment!
It would come down to what variable you wanted to test. Temperature? Salinity? What about light? (One in 24 hour light, one in 12 he and one in no light then repeated 3 times) then what "measure" would you use. Maybe it would be amount of hatched eggs in dry weight? Skim them off the surface and dry them through a sieve and you could see a relationship with the largest volume of hatched eggs being the "best" hatch rate.
So after weighing my options, I've decided to go with this! I'll probably start a topic in photos/journals to further explore this specific question, and outline and document the process. I think the first decision is to decide what plants and the amount of ammonia dosage. @KoolFish97 I'd love your help if you'd want to be involved!
For ammonia dosage I would highly suggest seeing if you can find another experiment similar that has doses that they use. Or another way might be to find what the "standard" ammonia concentration are for a brand/s that they recommend for cycling an aquarium. Though not a super awesome way about it, it will be based of a industry standard!
My advice with plants would be see what is the most cost effective for you where your local too then we could easily chose from that list viable plant decisions. (For example maybe not java as it's a relative slow grower when compared to many other choices, not saying a bad choice just might be viable to chose a cost effective fast growing species).
You could even slightly adjust the experiment and do the same amount of plants (by mass or individual plants) but do different species to see which is the most "effective" out of what you test. (Maybe even do similar growth styles but different choices like stem plants against eachother etc etc. Or even floating plants against one another)
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