Science Project using Marine Invertebrates

[deleted-83937]

Hi,

My daughter who is in second grade had been very much interested in Marine invertebrate when she visited the local museum. When it was time for her science project she suggested to see if she can do a project using the marine invertebrate. I checked with the museum and they were generous enough to allow us to do a project. They suggested us that she can do something like testing the behavior of the invertebrates towards light. Whether they will be attracted or not. Even though it sounds simple, it looks like a good project. The other question my daughter had was how some of the animals like sea cucumbers see.

They have sea urchin ( purple and pencil), sea cucumbers, black spring brittle star, branded brittle star, dwarf red hermit crab, mexican turbo snail.

I would like to see if the experts here have any other interesting idea to adapt for the project.

I am wondering what will be the procedure one should adopt to measure the attraction towards light or dark.

Thanks

BumbleBee

[deleted-132180]

Hello there,

This is a really cool project! One idea is to test the idea of phototaxis, the phenomenon where organisms move towards or away from a light stimulus (http://en.wikipedia.org/wiki/Phototaxis). For example, for all the sea creatures you've listed, what if you shined light of different wavelengths at them and record your observations of whether they will move towards a certain wavelength, move away from a certain wavelength, or whether they don't respond to certain wavelengths at all. Many creatures have developed ways to sense and respond to light because it's an essential part of their lifestyle. I did a quick google search and found an experiment protocol on testing algae phototaxis (http://www.udel.edu/MERL/Outreach/Teach ... s%20TE.pdf). Although the sea creatures you mentioned are a lot larger than algae, you can apply a similar idea to this project, and I'm sure that the local museum would love to help you out in planning out the experiments and doing them!

Let us know if you have anymore questions!

Best,
Connie

[deleted-83937]

Thanks Connie, we would like to pursue this idea of phototaxis.

I do have a question of different wavelength of light. Are you suggesting to use different color transparent paper for the different wavelength around the tank?

Regards
BumbleBee

[deleted-132180]

Hello there,

I'm not sure if using different colors of transparent paper would really equal shining lights of different wavelengths at your organisms. What I meant by different wavelengths is that visible light contains six different colors that are represented by lights of different wavelengths. For example:

Violet 380-450 nm
Blue 450-495 nm
Green 495-570 nm
Yellow 570-590 nm
Orange 590-620 nm
Red 620-740 nm

Shining lights of different wavelengths at the organisms just means shining lights of different colors at them. So you would shine a violet light, blue light, green light, yellow light, orange light, and red light and see how the organisms respond to lights of each color (or wavelength), since certain organisms are able to react to certain areas of the visible spectrum only. For example, I once saw this really cool exhibit in a museum where they had a tank of algae and six light bulbs inside the tank, each shining a different color of the visible spectrum, and the algae only aggregated towards the blue and green lights. Does the local museum have lights of different colors that you can borrow to shine on the tanks? Talking to them would be a good idea to see what ideas they can come up with. You can also ask them about the idea of the different colored transparent papers to see if that would work. You can probably also order something like this (http://www.amazon.com/LEDwholesalers-Re ... lights+red) to set up your own light that is able to change into different colors.

Let us know if you have anymore questions!

Best,
Connie

[deleted-83937]

Thanks Connie. My daughter liked this idea. I will check with the museum to see if they will allow us to do this.

Regards
BumbleBee

[deleted-83937]

Hi Connie,

We did our experiment at the museum today. We got our lights which you had recommended. The museum let us use the different colors. We tested them on Brittle Star, Sand Star, Sea Cucumbers

For each color of the wavelength the reaction of the above animals were different. Sometimes they ran away, buried themselves, elongated themselves, moved towards the light.

Do you have any suggestion on how to use the observation in our result. Before we started on our experiment we planned to see if they stayed or ranaway from the light, but did not expect them to show various reactions to different wavelengths.

Thanks
BumbleBee

[deleted-132180]

Hello there,

Wow, your results sound really cool! It must have been really fun for you and your daughter to try these different conditions and see how the different animals reacted to them. How you present your results will really depend on how you want to frame the story of your experiment. To keep things simple, you can go with your previous idea of phototaxis and just state whether the animals moved towards the light, away from the light, or just stayed in the same spot. Then, you can make some conclusions about which wavelengths/colors of light by which these animals are attracted or repelled. However, you can always add in extra information about the other observations you saw--I think the elongation and the burying are very cool discoveries. It's these unexpected results that make doing experiments even more exciting! How exactly are you and your daughter planning to document your experiments? Does she have to write up a lab report for class or something? If you let me know a little more about how she needs to present her observations, we can brainstorm about what would be the best way for her to present her data.

It sounds like your experiment went really well. I'm so glad to hear that!

Let me know if there are anymore questions.

Best,
Connie

[deleted-83937]

Hi Connie,
Thanks for the reply. My daughter need to submit a lab book where she will note her findings, but will use a 3 fold to display t it so the judges can see her project and rank them.

She wanted to use the colors of light as part of her experiment. Once I told what you suggested about modifying she thought it will be fun to use colors. She also told that when reading about the 3 animals she selected, she found most of them do not like light. So I also thought doing the color of lights make more sense since that might be something the animals might not got exposed too.

We looked at
1.https://www.sciencebuddies.org/science- ... html#using for lab note book

2.https://www.sciencebuddies.org/science- ... #checklist and was planning to use this as the guide for our display.

Regards

Bumblebee

[deleted-132180]

Hi Bumblebee,

Sorry for the late reply--I hope it's still in time before your daughter needs to submit her materials! I think you both got some really great results from your experiment, and if you basically follow the instructions in those pages that you showed me, it will be great. I think the most important part is to figure out what the main question your experiment is addressing and the hypothesis that you tested. Since it seems like your daughter is very interested in the different light colors and you both originally decided on the idea of phototaxis, I would probably frame your main question as something along the lines of, "How do different marine invertebrates respond to lights of different lights?" and your hypotheses can vary depending on how you want to frame them. You can, for example, make hypotheses for the individual animals that you tried based on the background research you did. For example, if you found that one of your animals really doesn't like light, then perhaps you can hypothesize that it will swim away from the light when you shine it on them. For your data, you can probably record whether the animals swam towards a specific light color, swam away from a specific light color, or did not respond at all. You can probably have an extra column documenting other behaviors that you have observed. Then, it would make for some very interesting discussion in your conclusions, where you can say that initially, you had expected the animals to either swim towards, swim away, or not respond, but then you see these other interesting behaviors. Other experts, please chime in if you have any other advice.

Let us know if you need anymore help! Good luck with writing up and presenting your results.

Best,
Connie

[deleted-83937]

Thanks Connie

We will plan it as per your advice. We are in good shape as per time and your advice was timely. We had completed the research section prior to our experiment, but could not
find much about the different colors. So we want hypothesis based on the intensity of the different color light. Is that good approach?

For control we monitored the animals in just regular room light and wanted to see if that is OK or is it not required for this experiment?



Regards

Bumblebee

[deleted-132180]

Hi Bumblebee,

It is totally fine that you could not find much about how these organisms respond to different colors (or wavelengths) of visible light--that probably just means that nobody has studied this yet and you and your daughter have discovered something completely new, which is awesome! I do realize though that this makes coming up with a hypothesis in relation to the different colored lights a little difficult though, since your experiment was a bit more exploratory as opposed to hypothesis-driven. However, we still should be able to come up with a hypothesis for this! In regards to your idea, for your experiment, were the different colored lights actually shined at different intensities? If you let me know a little more about your procedures, then I would be able to help you a little more. Why don't you think back to before you and your daughter did the experiment. Your initial question was how do certain marine invertebrates respond to lights of different colors. What did you two expect to happen with the animals based on what you did for your background research? How did you expect them to respond to the different colors? That would be a good basis for a hypothesis. Here are links to Science Buddies pages about generating hypotheses (https://www.sciencebuddies.org/blog/201 ... thesis.php, https://www.sciencebuddies.org/science- ... bles.shtml).

As with the regular room light, if I am understanding you correctly, you are using it as a control to represent something that emits all the wavelengths in the visible spectrum? It is a bit difficult to use that as some sort of control because you do not know what kind of wavelengths the light is actually emitting. What would probably be a better control would just be the dark, without shining any light on. In that case, you would probably expect your animals to not have any response, and you can compare that to conditions where you do have light shining on them.

I hope that was helpful. Let me know if you have any more questions and if you want to brainstorm more about a hypothesis for your experiment.

Best,
Connie

[deleted-83937]

Thanks Connie

We plan to do experiment in dark ( without light) as control and see what happens.

Meanwhile found some info about light wavelength and its effect in water. Maybe we can base the hypothesis on it

http://oceanexplorer.noaa.gov/facts/red-color.html

Regards

BumbleBee

[deleted-132180]

Hi Bumblebee,

That is an awesome find! This reminds me of a display that I had seen in a museum before (I think I had mentioned this) where they have a tank of algae and inside the tank, they shine lights that are of different colors of the visible spectrum, and you can see that the algae only swim towards the blue and green lights. Their reasoning for this phenomenon is that at the depth that these algae live in the actual ocean, only blue and green light are able to penetrate through and so they've only learned to respond to those light colors. I think your idea of basing your hypothesis on depth and how far the light can penetrate is a fantastic one!

Keep us updated on how your experiments are going, and let us know if you need anymore help. Feel free to share ideas about your hypothesis on here if you want to discuss them!

Best,
Connie

[deleted-83937]

Hi Connie,

It was so timely to see your response. Earlier this week my daughter came up with the following hypothesis.

Hypothesis.

Based on my research, my hypothesis is that

1. Sea Star will stay when shining red color light and run away from blue, green and purple

2. Brittle star will runaway from all of them.

3. Sea Cucumbers will stay in red color and will try to runaway when shining blue, green , purple color lights

Regards
Bumblebee

[deleted-132180]

Hi Bumblebee!

Those are great hypotheses! However, I do have one small suggestion. The phenomenon of phototaxis basically says that animals can respond to light by either going away or going towards it, so is there a specific reason why your daughter thinks that they will run away from these different colored lights as opposed to being attracted to them instead? I think your hypotheses are great, but people might wonder what the reasoning behind you thinking they will be repelled by those lights instead of being attracted. If you have some evidence that you found that may suggest that, that is great! Alternatively, you can consider the option of saying that you think they will not respond to red light, let's say, but will have a phototactic response to blue, green, and purple by going away or going towards the light? Just a thought!

Best of luck with your project. It sounds like you and your daughter are doing great experiments and having lots of fun thinking about your results!

Best,
Connie

[deleted-83937]

Hi Connie,

My daughter based her hypothesis based on the fact the most of the animals she was testing was nocturnal and also taking into consideration the intensity of color lights. Even the scientist at the museum told her about red light and blue light.

But she still thinks she can use your suggestion and also recorded her trails.

The one part we both are not sure if this is the correct way is the table where we are recording it

We have table where we have a column for time | No light | Red | Green | and we mark Yes or No

Yes= The animal responded by moving, hiding, burying, stretching etc
No= remained still or did not react at all
She also made observations on how they react and it will be below the table for that trial.

Now my question is to plot a graph, we would use one for each color with yes/no. Some animals reacted very quickly and other took some time. So I would appreciate if you have any suggestion to show the result.

Regards
BumbleBee

[deleted-132180]

Hi Bumblebee,

I think the way you set up the table is great. I don't know necessarily how you can present this data in a graph form because you are only recording yes or no responses, so I think the table you have will be sufficient. Do you have any graphs in mind as to how you would like to present your results? Like you said, I would have columns with No light, red, green, and time(?) and just record Yes and No underneath each of those columns for the animals in question. I do have a question for the "time" though--what do you mean by that? The amount of time the animals were exposed to the light? The amount of time it took for the animals to react? I do suggest to have an additional table after that where you will actually write in more detail what happens to each animal in these situations. So for example, I would have the columns No light, red, and green, and for example, let's say Animal A doesn't respond to "no light" and red light, but responds to green light by swimming towards it. Then, you can record under "no light" and red light, "No reaction", and under the green light, "Swim towards light". It might also be cool if you have some pictures of these animals to show them on your display board or even in your report!

Let me know if you have more questions.

Best,
Connie

[deleted-83937]

Hi Connie,

Thanks for your reply. We recorded the time the animals was exposed to the light and took note of at what time they reacted. Some time they react immediately and other time it took 10 mins. So we thought how many times they reacted with that time and use it in our graph

I do have a lot of pictures.

Regards
BumbleBee

[deleted-132180]

Hi Bumblebee,

Just out of curiosity, did you expose your animals to the light for the same amounts of time? For the animals that took longer to respond, did you try exposing light to them for shorter amounts of time to see how they reacted? Because if it took an animal about 10 minutes to respond to the light, it's hard to say whether their behavior is in response to the light exposure or if they're just deciding to move around in a way that's not dependent on whether the light is there or not. One way to try to get at this is if you expose your animal to a light for 10 minutes, you should also watch their behavior when there is no light for 10 minutes and see if they make similar movements. I don't know much about marine invertebrates and how long it takes for different organisms to respond to light, but 10 minutes seems like an awfully long time. Perhaps they really do have a slow reaction time... or their movements after 10 minutes are not directly related to a response to light at all. You should perhaps talk a bit with the scientist at the museum and see what they think about the animals which took significantly longer to show a response to the light. Also, when you say "sometimes they react immediately and other times it took 10 minutes", are you talking in regards to the same animal? So for example, if you shine red light at Animal A multiple times, sometimes they would react right away and sometimes they take a while. Or are you talking about different animals, such as "I see Animal A reacting quickly, but Animal B takes 10 minutes to react"?

Best,
Connie

[deleted-83937]

Hi Connie,

We exposed the animals to light for the same time on all our trials. I was referring to a sea cucumber that takes a longer time as they do not move fast. So I do not think it is going to be helpful for other animals.

Regards
BumbleBee

[deleted-83937]

Hi Connie,

I just wanted to let you know that the project won first place for the grade. Thanks for all your help.

Regards
BumbleBee

[deleted-132180]

Hi Bumblebee,

That is SO AWESOME! Congratulations! I hope you and your daughter had a great time doing the project and presenting the results--it was a really cool idea to work with marine invertebrates and see how light affects them.

Let me know if you need anything else, and thanks for letting me know.

Best wishes,
Connie