Setting Up for the Official Start!

Time to officially start the experiment. During this meeting, the trial box was more dry so I was able to complete my set up for the trial run. I placed one male and female inside the box. They are the grown up type (and possibly not virgins anymore). I used filter paper to serve as their food area and the poked holes on the box lid will provide them with enough air. After setting up my trial experiment, I moved onto setting up boxes for the actual experiment. For those boxes, the set up has to be the same so that the environment will act as a control instead of variable. I put in about 382.3g of dirt in every box, with each box weighing approximately 67g (without lid) and 95g (with lid) and poured in 200mL of distilled water. I also prepared labels and data tables for each of these boxes to keep track. If all goes well (especially the trial box), I will just have to put in the different experimental groups of pill bugs in the boxes and then the experiment will begin!

The trial box looks like:

The pill bug (male) on the filter paper is trying to get food!

Pre-experimental Trial!

After planning the experiment, I prepared a trial set up to test if my setting would work for the actual experiment. I used a small food container half filled with dirt, along with a pair of egg container for a shadowed area. In order for the dirt to be moist, I poured 300mL of water but after a while, the egg container softens and is soaked with water. Too wet, opps! For next week, Mr. Calos will bring in more of the same materials so I can set up for my real experiment. Meanwhile, I have to wait until the test box dries so I can put in two bugs from the colony tank. Also, my meeting time changed to Thursday due to a different spring semester schedule. I will work independently on the experiment every Tuesday.

Planning the Mating Experiment!

To test the male-effect on pill bugs, the experimental setup requires different sexes of pill bugs to be separated into different groups. During the month of February to March, it is the time of the year that female pill bugs are predicted to be very probably entering the pre-parturial intermoult (179). The experimental design will involve the following groups of pill bugs:

                  1) Negative control group = female + female
                  2) Positive control group = male + female*
                  3) Treatment group 1 = female + female, each will be further mated once
                  4) Treatment group 2 = female + female, each will be further mated twice
*The purpose of positive control group is to be compared with the other three groups.

 All of these groups of pill bugs should be placed into identical tanks/boxes, filled with moistened dirt and enough food for several months and maintained in the same conditions. After two or three weeks, females from the treatment groups should be placed into petri dishes to individually confront a male for a limited amount of time (e.g. one hour). Encounters should be repeated on a regular basis until “a male initiated a mating sequence (typically consisiting of mounting attempts and two successive mating postures to inseminate the right and left female genital ducts)” (179). Towards the end of the experiment, females in the negative control group would have to be dissected to verify their virginity as well as to confirm the presence of sperm in the genital ducts of all other females in the positive control and the two other treatment groups.


For the full text of the published research article, please visit:
http://www.tandfonline.com/doi/abs/10.1080/07924259.2010.9652331

FRANÇOIS LEFEBVRE & YVES CAUBET (2010): Female-extended control over their reproductive investment: the role of early mating interactions on oocyte maturation in the terrestrial crustacean Armadillidium vulgare (Latreille, 1804), Invertebrate Reproduction & Development, 54:4, 177-186.

Slight Break for Service Day!

In honor of Dr. Martin Luther King Jr., today is community service day for all Emma students. My service was the Boys & Girls Club of Troy Canvas Painting Project, held on campus. I have to miss my internship today but I still regularly took care of the pill bugs that I sorted out last week. Every couple of days, I will have to water the dirt, so that the environment get moisty. I feed the pill bugs with fish food as well. Ready to start the experiment soon!

Sorting Bugs Out!

Mr. Calos orderd pill bugs during the meeting on Wednesday. They came in today so I have to sort them out, or else they would die in their white foam container.

These are the procedures that I performed when sorting the bugs by gender:
#1 Transfer all bugs into a large plastic transparent container
#2 Gently use paint brush to remove the bugs one by one onto petri dish
#3 Flip the bug upside down on petri dish
#4 Place petri dish under microscope
#5 Observe carefully under bright light
#6 Wait until bug is still on the dish
#7 Focus on the hing legs part of the bug
#8 Place the bug into the tank (either male or female) that I have prepared earlier
#9 Mark down number of bug(s) in each tank
#10 Repeat procedure 1-10 until all bugs are sorted

The process took more than two hours but it was rewarding. In the end, I sorted 11 males and 34 females. It is definitely a great start to the project!

This is the setup...notice the bug in the petri dish!

Research and Finish Setup!

From last week’s assignment to look for a reliable published reading, I came across pill bug's “male effect”. The “male-effect” is characterized by a significant shortening period of the pre-parturial intermoult (PPI) during which oocyte maturation spontaneously takes place. The prolonged presence of male along with females is known to boost female reproductive physiology. From the paper, the study resulted in the ideas that the “continuous presence of a male can speed up vitellogenesis and the moulting cycle, so to reduce female PPI by 15-20 day” (177). Results also indicate that the earlier and longer the copulations, the stronger the “male effect” can be. From the published data, a conclusion of “females are adjusting their reproductive physiology according to the presence/absence and the intensity of male mating stimuli” (177) was proven. During this meeting, Mr. Calos ordered pill bugs. I also prepared two tanks (for the convenience after sorting out males and females) in preparation for the bugs to arrive on Friday.


For the full text of the published research article, please visit:

http://www.tandfonline.com/doi/abs/10.1080/07924259.2010.9652331

FRANÇOIS LEFEBVRE & YVES CAUBET (2010): Female-extended control over their reproductive investment: the role of early mating interactions on oocyte maturation in the terrestrial crustacean Armadillidium vulgare (Latreille, 1804), Invertebrate Reproduction & Development, 54:4, 177-186.

Project Begins!

This week, I am actually starting the project - Mr. Calos and I set up my experiment station downstairs of Weaver. I then started researching about the determination of gender for pill bugs. I interestingly found out that male pill bug has a pair of long blade-like appendages near its hind legs while female does not. The way to know that is to hold the bug gently and turn it upside down to check. Here is the link as to where I got the information: http://snailstales.blogspot.com/2008/02/is-it-boy-or-girl.html. I then moved on to observe some of the pill bugs; I was not able to get one by just using my hands, so I will have to use some forceps to help me. Before my next meeting, I will have to look for some published books that discuss about pill bug’s sexual behaviors, and learn more.

Here is a picture of what a male pill bug will look like: