Eddy EganSeptember 18, 2008Mrs. Contreras AP Biology – Pd. ¾ odd

Date of Experiment: September 16, 2008Time of Experiment: Approximately 9:20 A.M.

Kinesis, Taxis, and all around Behavior of Armadillidium Valgare (Pill bugs, Sow bugs,

Roly Polyies) in response to wet and dry environments

The experiment that has taken place is based on the behavior patterns of the

creature known as Armadillidium Valgare, otherwise known as pill bugs, sow bugs, or

roly polyies. These small creatures are classified in the phylum arthropoda, the

subphylum crustacea, and the class malacostraca as terrestrial Isopods meaning “any of

various small terrestrial or aquatic crustaceans with seven pairs of legs adapted for

crawling.” (AudioEnglish) The word crustacean brings to mind lobsters, crab, and

shrimp, all of which breathe through gills just like these pill bugs. (Wright) That means

that if pill bugs have the ability to respire through gills like a water creature and lack a

waxy cuticle layer, then they should favor water over dry land in order to breathe and

avoid drying out. As seen previously these bugs are in the family Armadillidium, which

can clearly be seen since they look like tiny armadillos.

In order to fully understand the behavior of these small creatures one must know

what kinds of behaviors animals have. The study of these animal behaviors is called

Ethology. Merriam-Webster defines behavior as “anything that an organism does

involving action and response to stimulation,” but sublevels of behavior can be obtained.

These sublevels include learned and instinctive behaviors. (University of Vermont)

Learning is the modification of a behavioral tendency by experience (as exposure to

conditioning) (Merriam-Webster Online Dictionary). Learned behaviors come in many

forms as well, such as Associative learning in which an animal learns to associate one

stimulus with another. (University of Vermont) Observation learning, where an animal

watches what to do, then can do it repeatedly. And finally, Insight learning, or basically

looking into the situation and being able to solve a problem or use a suitable behavior the

first time the animal is exposed to the situation (University of Vermont). Instinctive

behaviors do not require any learning or previous training and are more or less built into

the organism. (University of Vermont)

Behavior also includes the movement of an organism in its environment; these

movements come in two forms. The first form is Taxis or the responsive movement of a

free-moving organism or cell toward or away from an external stimulus (American

Heritage). This means that there is no random movement away from the stimulus, but

rather an organized turn and go away from the stimulus to a place that suits the organism

more. The second type of behavioral movement is Kinesis or a movement that is a

response to a stimulus but is not oriented with respect to the source of stimulation.

(WordNet) Rather than moving in a so called orderly fashion, the organism moves in

random directions to get the favored results that it wants.

Procedure

1. Acquire pill bugs from Laboratory supervisors very carefully by using

paintbrushes to transport them from one container to another, we do not want to

injure or harm the bugs in any way.

2. When the large segregations of pill bugs are together, observe for about ten

minutes but the longer the better. (We are trying to witness them in a natural

environment. With all of the trauma of moving from different containers this may

not be very possible.)

3. While observing the pill bugs record any and all observations. This includes pill

bugs gathering in one location, moving to the outer rim of the bowl and includes

the reactions to other pill bugs. Also, look at the characteristic features of pill

bugs. How many legs do they have? How many back sections do they have?

Draw a detailed sketch of a pill bug after finding this entire out.

4. After you have finished your observations and have written them down. Ask your

laboratory supervisor for two connected Petri dishes. Be sure to thoroughly rinse

them out and dry them off to rid them of any contaminants that were previously in

them.

5. Next, line one side of Petri dishes with dry filter paper. The other side will be

lined with moist filter paper (Be sure to make it “moist” and not “wet”, we do not

want to drown the pill bugs)

6. Quickly but carefully transfer 10 pill bugs from the large collections in the bowl

into the Petri dishes leaving 5 on each side.

7. Every 30 seconds for 10 minutes record the amount of pill bugs on both the wet

and dry sides of the Petri dishes. Record any additional observations.

8. Return pill bugs to laboratory supervisor and clean up your station.

Data

Observations before pill bugs have entered Petri dishes

The tiny crustaceans that we had observed were very interesting to watch. The

bugs were very active and loved to crawl all over each other. The small pill bugs seemed

to fear the large pill bugs in fear of being run over or flipped over. When filled over they

had a very hard time flipping back. If the happened to be disturbed in their plastic

environment then they could just curl up into a ball and escape danger in a small way.

They never seemed to migrate towards the center of the bowl in fear of being out in the

open and alone, a mistake that could cost them dearly in the natural world.

Analysis of Graph 1

The outcome of our experiment turned out to be not what I had expected. Our

results show what looks to be a fairly even field with both highs and lows but with the

use of math we can see a difference. The average number of pill bugs on the wet side had

been 4.5 which is not the majority. This completely disagrees with my hypothesis in

stating that the pill bugs would flock to the wet side due to their gills and not wanting to

dry out. I believe that the reason for the pill bugs to migrate away from the wet side may

have been from a chemical residue in that side. Our teacher had informed us to

thoroughly rinse and dry out the Petri dishes prior to working; this had not been done to a

great extent. Furthermore, I noticed that some larger puddles may have been present on

the wet side of the Petri dishes. That extra moisture could potentially drive away the pill

bugs since they do not want to drown. Even though our results may have seemed to be

mistaken the class averages seemed to smooth things out a bit more and looked to lean

more towards the wet side. Since every experiment needs to be completed many times in

order to be confirmed correct, this was a good experiment that showed us the necessity of

it. If one set of results may have been wrong, there are many more that can prove the

validity of it. Therefore, in a greater scheme of things my hypothesis proved to be correct.

Taxis had taken placed and the pill bugs located themselves to the wet side in response to

a stimuli, and it wasn’t in a random manner of moving. This idea can be compared to

flipping over a rock. Although the ground may be moist and comfortable for the isopods

another stimuli changes their behavior. This time it is the light. They use their innate

behavior of taxis to find darkness where it is cooler otherwise they curl up into a ball

which is referred to as a negative photo taxis.

Since the possibility of altering the pill bugs behavior may have been chemically

induced, other behaviors could arise as well. The pill bugs had been ripped out of their

natural homes and forced into laboratory experiments. This constant moving around puts

a lot of stress on the organism and therefore changes the behavior of it. It is nowhere near

a natural environment so they can be acting completely different, in ways that show it to

be running around frantically, or curling up into small protective balls. To make this

experiment more beneficial to our knowledge, field observation is a good way to view the

natural orientation of the organism. Using dry and wet patches of natural ground that is

close to their homes provides for a good foundation of natural but at the same time

artificial simulation. These bugs don’t live in plastic Petri dishes so to do observations in

them seems rather impractical.

Analysis of Class Data and Researched Data

The class data looked to favor the wet Petri dishes in the experimentation, but this

margin was very small. On a larger approach that I used on the internet, the results

outweighed the dry Petri dishes and the wet ones were clear winners. (BioWeb) This

shows the possibility of different variables that could have affected all of our organisms

and more sources of error that could be found.

As stated before, Pill bugs are relatives to many water dwelling creatures. With

the naked eye, even a fifth grader could spot the similarities between something such as a

crab or a shrimp, with a pill bug. They both have those hard outer shell coverings

enabling them to be protected when harm is prevalent. But with those hard shells also

comes key places where they are segmented. This allows the creatures to be mobile as

well as having the benefits of being protected. We have talked about the occurrence of

gills in pill bugs and with that information one can use previous knowledge to conclude

that the pill bugs like the moist environment. Even if they like it that does not mean that

they can just breathe underwater like crabs and shrimp do. They have moved onto the

land for a reason and therefore also develop the skills necessary to survive on land. This

is why you would find so many of these bugs underneath rocks in cool, dark, moist

environments. The sea dwellings friends of the pill bugs love the dark caves underwater,

you can witness this yourself by going to a shallow stream and flipping over rocks. When

the rock is flipped over, crawfish come out from their hiding due to positive photo taxis.

Meaning that due to the change in light, the crustacean moves itself back into a dark area.

Armadillidium Valgare are very simple, but very interesting beings. They come in

many different sizes, shapes, and species and are very easy to experiment on. For this

reason I think it would be beneficial to further our studies on this bug. Instead of in the

laboratory, I would rather go into the garden and watch them crawl around in their small

world. We can observe them and see if they use kinesis or taxis in the search of not only

moisture but food, mates and light. Additionally, we can tie into our other lab by

witnessing behaviors that happen during reproduction. The definition of Biology is to

study living organisms and how they interact with each other and their environment. That

means that with this small additional experiment we can tie together different topics and

define Biology ourselves.

References

Princeton University. "Isopod." AudioEnglish. 16 Sept. 2008

<http://www.audioenglish.net/dictionary/isopod.htm>.

Princeton University. "Kinesis." WordNet. 16 Sept. 2008

<http://wordnet.princeton.edu/perl/webwn?s=kinesis>.

"Taxis." The American Heritage® Dictionary of the English Language, Fourth Edition.

Houghton Mifflin Company, 2004. Answers.com 18 Sep. 2008.

University of Vermont. "DOMESTIC ANIMAL BEHAVIOR." DOMESTIC ANIMAL

BEHAVIOR. 16 Sept. 2008 <http://asci.uvm.edu/course/asci001/behavior.html>.

Western Kentucky University. "Animal Behavior Lab." Bio 114. 16 Sept. 2008

<http://bioweb.wku.edu/courses/biol114/behavior/pill_bug1.asp>.

Wright, Dr. Jonathan. "Pill Bugs." Northern State University. 1997. 16 Sept. 2008

<http://www.northern.edu/natsource/invert1/pillbu1.htm>.

Date of Experiment: September 16, 2008Time of Experiment: Approximately 9:30

Mating Behaviors in the Drosophila Melanogaster (Fruit Fly)

I. Introduction

Mating behavior can be viewed directly but includes very subtle actions. Female

mating behavior is characterized by mostly evading male advances until she is ready

when she stands quietly and copulation occurs. In male mating behavior the process is

very variable between species but can generally include seeking, intromission, thrusting,

and a period of ejaculation (SCVD). In fruit flies, these steps happen in a different way

but the basic idea is there. Orientation is the first step and basically includes the male and

the female meeting one another. Next is the male fruit fly playing a song, which is really

him just vibrating his wings. He does this in order to attract the female, the same way a

human may use flowers or sing a midnight song at the female’s window. If the female is

enticed the two fruit flies will be very close to each other and the male will begin licking

the female genitalia. This process is used to rid the female genitalia of any residual sperm

from another fruit fly and to turn on hormones for the use of pregnancy. Copulation may

finally be achieved after this process and the start of pregnancy begins. Of course this

may be the ideal situation in this seemingly simple process but many forms of enticing

have to be done in order to obtain a female. All of these things are regulated by the

behavior of the male, which means one can’t just walk up to a female and begin this

process. She will definitely reject you right away, skewing your chances of survival. For

this reason the male can use a multitude of behaviors in order to entice. They include

wing vibration; the male extends one or both wings from the resting position and moves

them rapidly up and down. Waving, the wing is extended and held 90º from the body,

then relaxed without vibration. Tapping, the forelegs are extended to strike or tap the

female. Licking, the male licks the female abdomen. Circling, the male postures and then

circles the female, usually when she is nonreceptive. And finally, Stamping, the male

stamps forefeet as in tapping but does not strike the female. The female exhibits

behaviors too but to a much lesser extent. They are based more on the shunning of a male

partner in order to seek an ideal one. These behaviors include Extruding, a temporary

tube like structure is extended from the female’s genitalia. Decamping, a nonreceptive

female runs, jumps, or flies away from the courting male. Depressing, a nonreceptive

female prevents access to her genitalia by depressing her wings and curling the tip of her

abdomen down. And lastly, Ignoring, a nonreceptive female ignores the male. (Lab 11)

All of these behaviors are shown in order for you to observe them in your experiments.

They all happen very rapidly and therefore one must know what they all are. With all of

my previous knowledge of the fruit flies and some common sense I have came to the

conclusion that, if two fruit flies (male and female) are placed in the same Petri dish, then

they will not exhibit any mating behavior.

II. Procedure

1. Prepare a working area to look at the fruit flies days before your experiment. This

means to cut a circle into an ice pack that has the same circumference as a

standard sized Petri dish using a scalpel.

2. Remove the foil layer

3. Compress the interior of the ice pack about 1-2 cm

4. Press Petri dish into the ice pack so that it fits snugly and then put the whole thing

in the freezer.

5. After the ice packs are completely frozen remove them from the freezer and place

them on your lab table. Your laboratory supervisor will now give you a vile

containing both fruit flies and a medium for the fruit flies to live off of.

6. The fruit flies have been chilled for twenty minutes so that they are temporarily

knocked out. This means that you must work very fast and very carefully to

extract them from the vile with a paintbrush onto the working area of your Petri

dish/ice pack station.

7. Under the eye of the magnifying glass, separate a male and a female and place

them into a mini Petri dish.

8. Set up a thermal light in order to observe the fruit flies from above and also to

warm them up to a higher temperature.

9. Place a heat sink in front of the flood light to absorb some of the thermal energy.

We used a fishbowl of water for this procedure.

10. Observe the actions of the fruit fly with the naked eye, once the flies get very

close go to step 11

11. Observe the actions of the fruit flies under the eye of a stereoscopic microscope

for as long as your laboratory supervisor lets you, have one partner look under the

microscope while another is recording your observations. If nothing is happening,

then write that down too.

12. When the time limit is up (As much class time as you have) return the fruit flies to

the vile and then return them to the laboratory supervisor.

13. Fully clean up your station after the experiment

III. Data

Unfortunately, there was not much taking place in the realm of our Petri dishes.

The fruit flies were very unreceptive and stayed at completely different sides of the Petri

dishes. While getting very tired of watching the flies at different sides of the dishes, we

decided to try and coax them into becoming closer by tilting the Petri dish sideways in

order for the flies to be next to each other. After being close to each other for about one

second the flies then reported back to opposite sides of the dishes yet again. While

observing other groups in our class do the same experiment, not much could be analyzed

as well. The entire group of fruit flies, from every vile, had very unresponsive flies. There

was only one group that actually had two flies come in close contact with each other.

That close contact included some very strange behaviors of the female, none of which I

had ever seen before or had been introduced to. The female was seemingly hitting the

unresponsive male on the head with the posterior side of her body. This shows that nature

does not go by the textbook but rather observations are being made every day and there

are paradox’s to almost everything.

IV. Discussion

My hypothesis was proved entirely correct by my observations even though they

were at a complete low. The fruit flies had absolutely no interest in each other and a

multitude of reasons can explain why. The first reason can also be classified as a source

of error. The laboratory that had given us the fruit flies had mixed the two genders

together. This was a huge mistake. The lab directly called for virgin fruit flies and being

that fruit flies are extremely promiscuous, the validity of the whole experiment is off.

Rapid conception could have taken place in the vials and severely altered the behaviors.

Another variable that could have arisen from that heterogeneous mixture could have the

males shunning the females since they had already mated and did not want the process to

happen again. On top of that costly mistake of mixing the two genders was the way of

stunning the fruit flies. They had been in an extremely cold environment for twenty

minutes. Not getting into any damage that may have occurred inside their small bodies,

they might have just not thawed out yet. Being kept at freezing temperature rapidly slows

down circulation and makes everything slow moving and death would ensue if left there

too long. It might just be that the thaw time was not long enough and if given more time

the flies could have warmed up to each other. In a book that I read called Survival of the

Sickest they happen to mention that when frozen, water in your blood will crystallize.

The crystallization of the water will tear straight through blood vessels leaving the

creature very injured or dead when thawed out. This is why humans cannot be

cryogenically frozen. On the other side of things, although the flies were also given a heat

lamp in order to observe them and warm them up, too much of something can be

detrimental. At the start of our study we didn’t have a heat lamp, and then received one a

few minutes in. The problem with that is that the heat was too much for the fruit flies.

The proteins in their small bodies could have been denatured extremely fast and caused a

lack of movement in them. Many experiments can be built off of this one but one that

would be the most entertaining is observing agonistic behavior. Males in every species

are known to compete for females and this is no difference. By putting one female

between something such as 2 or three males, a fight would be completely ordinary. The

behaviors could be observed and we could write down what each behavior looks like and

how it helped the insect to survive against its rival. Another experiment I would like to

see is based on fruit flies and fruit. I would like to see if fruit flies show agonistic

behavior in relation to food. To me it seems that it wouldn’t be likely since a piece of

fruit is extremely larger than each fly. That means that there would be no competition for

food. But if the piece of food was small and both insects were starving for food, would

they then have the need to fight? Only experiments will prove the outcome of these

questions.

V. References

Lab Eleven: Animal Behavior

Saunders Comprehensive Veterinary Dictionary. "Mating Behavior." 2007. 16 Sept. 2008

<http://medical-dictionary.thefreedictionary.com/mating+behavior>.