Over the whole year from the beginning to now, I have
started from deciding my own topic to conducting and rounding up my own
research on the sexual behaviors of pill bugs. Although the key factor in this
experiment is time, I am glad that I was able to finish the four cycles and
theoretically prove my hypothesis that the “male effect” does exists. In fact,
the statement is already proven by purely observing the stages of growth the
baby pill bugs are in right now. Currently, the biggest challenge is counting
the pill bugs, for the purpose of statistical prove and analysis. My mentor,
Mr. Calos, wish for me to publish a paper or report next year, so the
statistical data is very important and will accurately support my hypothesis with
real proof. When completing my poster, my report has been laid out with a
format of a formal lab report, so the information that I have written will be
useful for that. To reflect on my internship for this past year, I would like
to present some of the challenges I have come across. First, it was gender determination. To determine the gender
of pill bugs under the microscope can be tricky, and I have to be extra careful
to not make a mistake, hence I have to observe each bug for at least 30 seconds
with more than just a few looks at the hind legs to confirm its gender and
minimize errors. I have improved in doing this in a less timely manner, which
is satisfying. Second, it was managing the living environment for pill bugs.
Pill bugs entertain moist areas; therefore the spraying of the tank has to be
maintained on a regular basis, while balancing the risk of growing molds or
fungi in the tanks. Even now, the growing of fungi occurs but the most helpful
thing to do is to just remove them and re-feed the bugs. Third, it is
challenging to run two separate trials at the same time, because the difference
between the two outcomes makes it tough to determine whether the hypothesis is
defeated or supported based on just the different outcomes. While the most
recent challenge is to count bugs quickly and using bare eyes to spot them
takes a very long time, I am enjoying the process of seeing little pill bugs
climb up and out of the soil. Some successes I have experienced are the regular
schedule that the cycles lie on, easily allowing the time control to be more
accurate and fair to the other sets of pill bugs. Another is gaining the skills
of sexing bugs as I become more effective. Time-management planning also plays
a vital role in this experiment. I was able to keep the two interactions with
males in the same timeframe. Although the four cycles of the experiment ended,
I am still working in my final stage of counting the bugs, but an early thanks
to Mr. Calos for his guidance and help all along.
EWS Science Internship
Friday, May 18, 2012
Thursday, May 3, 2012
Cycle 4!
Exciting news, it worked! New babies are born in Box #8, my
second experiment trial (using Boxes #5-8) is actually closer to my predicted
results than my first trial. The babies found in box #8 are newborn, they are
so tiny compare to the ones in box #6, and they are still white, not
transparent (as they develop transparent layers and a dark line in the middle
of their body when they get older). The comparison mainly lies between box #7
to box #8, with box #8 having an additional encounter with a male for two more
hours than the ones in box #7. The first
trial is also going well, with babies appearing in box #4, but interestingly
enough, box #3 has no babies. This is the end of the experimental period, even
though my results in my first trial and my second trail vary a little bit
between each other, I have proven two things: prolonged presence does have an
influence on the pregnancy period of the female, secondly, that female pill
bugs can still reproduce with no male presence.
Here’s a picture of a baby in box #6 with the parent,
compare the size:
The size of one baby is tiny compare to a grown pill bug.
Thursday, April 26, 2012
Cycle 3!
Cycle 3 is the week when baby pill bugs are being born in
large numbers. Box #6 shows the most positive results in terms of closeness
towards the predicted outcome. What this means is that Box #6 is the box with
the longest presence of male (because it has a male all along), and its babies
are born the earliest since when I discover babies in Box #6, there aren’t
babies in Boxes #5, 7 or 8 yet (they are in one set of experimental trial),
which supports the “male effect” exists. All throughout this week, I am observing the
babies growing and I found an interesting factor that even in Box #1 and Box #5
(where it contains female x female, supposedly my negative control group) have
babies. So I left it the way it is but still found out that the babies born in
Box #6 grew faster and are in bigger size than the new born ones in other
boxes, proving that prolonged male existence does have an impact. Next week,
cycle 4, I am going to continue observing the appearance of babies and look for
babies that will be hatched in Boxes #3, 4, 7 and 8. One more week till
experiment is complete!
Thursday, April 19, 2012
Cycle 2!
Start of cycle 2 on April 12th and 17th for #1,5 and #2-4,6-8 respectively. Following the plan of the experiment, this is also a week without any interferece on anything. As usual, continual spraying of 10-15 sprays per time to keep the area moist. One interesting thing is because of the moist, the left-over food has been covered with fungi, most likely molds. In #8, I found a mushroom on Tuesday; I was unable to take a picture of it but it looks a flower. It won't stay but I had to remove all the filter papers for the food area as well as under the "hosue" made by egg containers. Some of the containers actually have mold on them too so they were replaced. It is mostly maintence work this week and the interference of male presence will occur next week. Meanwhile, I had to control the amount of food fed to them so to prevent mold growing on the soil and I cannot spray on the food but the soil.
Here's a picture of that fungi mushroom that grew in #8:
Here's a picture of that fungi mushroom that grew in #8:
I just learned about fungi in my AP Biology class so it was very cool to see one;
I brought it to class and we were all fascinated!
Thursday, April 12, 2012
Cycle 1!
This week is the first week of cycle 1, which is planned for everything to settle and stay in the initial setting, with no inferference except continual spraying for a moist environment and feeding. To continue on my last blog record, I sex-ed bugs to complete my set up to have 14 females and 2 males in #1-8. All of the bugs in #2-4 and #6-8 are placed in on April 10, 2012, which means cycle 2 starts on April 17th for them. With #1 and #5, they are kept the same since the start of the experiment, so despite the fact that their cycles started on April 5th, it is all right for them to stay for the four cycles. As for all other bugs, I placed the other sex-ed males in a colony tank and some of the ones are left unsex-ed in another colony because they hid under soil. However, I found some babies in that tank, they are tiny in size compare to grown pill bugs, about 2mm long and 1mm wide. Their bodies are transparent but their structures are already developed.
Here's a picture of the baby pill bug that I isolated and placed into a petri dish:
Here's a picture of the baby pill bug that I isolated and placed into a petri dish:
I have seen a couple more babies in the un-sexed colony tank, exciting!
Thursday, April 5, 2012
Official Start of Cycles!
The bugs came in on yesterday, I placed them all in a "colony tank" and sorted them out today. Unlike last time, there are a lot more males than females, which is a big CHALLENGE because I need more females than males. I ended up only being able to start #1 and #5 with four females. For all #1-8, I sprayed 30 times because they seem to be drying out faster than I expected. Throughout this and the coming week, I will be sexing more and continue taking care of the rest of the sex-ed bugs.
Here's me looking into the microscope and waiting for them to expose their hind legs:
Here's me looking into the microscope and waiting for them to expose their hind legs:
Fun observation: pill bugs get "impatient" under the light as they struggle to escape from it.
Sexing them takes less time now, even though it still requires about 1-2 minutes per bug.
Thursday, March 29, 2012
Final Preparation!
After confirming that the experimental trial worked, it is time to start. I plan to start off with two experimental sets, hence I will need 8 boxes, 4 boxes for each set. Each box is set up like the pre-experimental trial box, with approximately 280g of soil, 200ml soaked water, a little shelter made by the egg container and a food area shaped by a piece of filter paper (that way, there won't be any molds). I came in late this week to spray 15 times in #1-8 to moist the area in preparation when pill bugs come in next week. I will briefly explain again how #1-8 is used. In #1 and #5, there is the negative control group, female + female. In #2 and #6, there is the positive control group, male + female, which we can expect a second generation. Then #3 and #7 are the treatment 1 group, female + female with periodic interaction with males for once. Last but not least, #4 and #8 are the treatment 2 group, female + female with periodic interaction with males for twice. Once they all come in next week, I will sex them and then the cycle starts!
This is how my experimental set-up is...(cleaner than it usually is)
This is how my experimental set-up is...(cleaner than it usually is)
See the one experimental set on the left - the four piled up boxes.
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