Chthamalus Barnacle Case Study

Exercise 1:

[ 3.1 ] Which barnacle species ranges into the warmest water? 


The barnacle species that ranges into the warmest waters is the Chthamalus barnacle. They tend to range farther in southern waters compared to the Semibalanus

[4.1] On average, how many high and low tides will a given spot on the coast experience in a day, and why?

On average a given spot will experience two high tide and two low tides in a day. The tides are experienced due to the moon gravitational pull. The low tides are experienced when we are facing 90 and 180 degrees away from the moon. Then the high tides are found when we are facing the moon and when we are facing away from the moon.

[4.2]What is a spring tide and when does it occur?

Spring tides occur

during the new moon and the full when the sun, earth, and moon are all aligned together. This happens every two weeks when the sun and moon are aligned there are parallel gravitational forces. This in turn create very high and very low tides.
4.3 ] What is a neap tide and when does it occur?
A neap tide normally occurs when the when the sun and moon are 90 degrees from each other when compared to the earth. The gravitational pull is not long parallel because the earth, sun, and moon are not aligned. The moon and sun are perpendicular to each other. When the neap tide occurs the high tides are unusually low and the low tides are unusually high. This happens every two week between each spring tide.

[ 6.1 ] How many high and low tides are there each day?
There are two high tides and two low tides each day

[ 7.1 ] What is the height of each of the following in your study area?
Spring high tide:
 4.80m

Spring low tide:
 0.80m

Neap high tide: 3.60m

Neap low tide: 2.00m

[ 7.2 ] If you are an organism that must remain submerged at all times, what is your maximum height on the rock? Explain.
If I was an organism that had to stay submerged under water at all times the maximum depth in the water that I would go to 0.80m. During the spring low tides the max height the water reached was 0.80m this is the lowest of the neap an spring tides. If I was a barnacle that doesn’t move at all my entire life I wouldn’t want to be any higher because I would be out of the water if I were any higher during spring tides.

[ 7.3 ] During approximately which days in the 14-day tide cycle do organisms living low on the rock experience their greatest potential exposure to air? Explain.
Organisms are would experience the greatest threat to air exposer on day 4. This is because this is when the spring tide occurs and the low tides are abnormally low and the high tides are unusually high.

[ 7.4 ] During approximately which days in the 14-day tide cycle do organisms living on the upper part of the rock face their greatest potential exposure to air? Explain.
Organisms are would experience the greatest threat to air exposer on day 4. This again is due to the spring tide that is occurring at this time. Spring tides have high tides that are unusually high and low tides that are unusually low.

[ 8.1 ] Briefly describe what you notice about the distribution patterns for each species on the following days. Do both species settle on the same parts of the rock face? Do their distribution patterns of the rock face change over time?
Days 1–7:
Days 1-7 I noticed that there was a pretty even destitution of each of the barnacle species on the upper and lower part of the rock.

On day 28:
On day 28 I noticed that there was a lot more of the Semibalanus barnacle species on the lower portion or the rock compared to the Chthamalus species which occupied the higher area of the rock. This was not the case on days 1-7 where there was an even distribution of the two species. The top of the rock consisted of mainly the Chthamalus species and some of the semibalanis species as well. The Chthamalus seem to be attaching to the upper part of the rock.

General observations:
From general observation the Semibalanus Barnacle species would attach at upper portion of the rock and then would fall off shortly after and more would pop up at the low potion of the rock over time.

[ 9.1 ] Hypothesis:
I hypothesize that the two barnacles species will become more plentiful on different areas of the of the rock the Chthamalus barnacle will occupy the upper portion of the rock while the Semibalanus will occupy the lower portion of the rock.
Exercise 2:
[ 3.1 ] Record your results in the first (Sample 1) row of Data Table 1, below. DATA TABLE 1: VERTICAL DISTRIBUTION OF BARNACLE
1meter 2meter 3meter 4meter 5meter
Sample S C S C S C S C S C
1 23 5 9 13 5 12 1 13 0 0
2 16 9 2 16 3 15 0 5 0 0
3 15 14 6 16 1 22 0 8 0 0
Range 7 5 3 3 2 7 1 5 0 0
Average 18 9.33 5.66 15 3 16.3 0.33 8.66 0 0

[ 5.1 ] Using your numerical results, describe the vertical distribution of barnacles on the rock face.
Starting at the one-meter mark there is a large abundance of the Semibalanus species and a very small amount of he Chthamalus barnacles. The difference in number its pretty significant with about 18 Semibalanus and 9 Chtamalus on average. Traveling up the rock there Chtamalus becomes much more abundant. At four meters on average there are 9 Chthamalus and less than one Semibalanus barnacle. Once at 5 meters neither species can be found.
[ 6.1 ] Select a height between 1 and 4 m that you think would be interesting to sample over time. Based on your hypothesis and the observations you’ve made so far, how do you predict the distribution of the two species would change over time at the depth you will be sampling? Explain.
My selected height is at 3 meters I think that the number of the Chthamalus barnacles will spike and the Semibalanus barnacles will be come less abundant and increase at a much slower rate. Over 14 day I believe that each of there species will see a decrease in total number. I believe this because when looking at the data table the numbers seem to start to fluctuate at the 3 meter point.

[ 7.1 ] Record the number of individuals of each species in the first (Sample 1) row of Data
DAY 2 DAY 4 DAY 6 DAY 8 DAY 10 DAY 12 DAY14
Sample S C S C S C S C S C S C S C
1 5 4 6 6 9 7 8 9 6 14 5 14 4 13
2 4 5 1 9 3 13 2 14 3 15 3 18 4 23

[8.1] Using your numerical results, describe the temporal pattern of barnacle distributions
The pattern I saw was that the Chthamalus barnacle did become more abundant in in number a lot more quickly than the Semibalanus barnacles did at the 3 meter point on the rock.

From day 10 to day 14 the chthamalus barnacle did have a significant increase as I previously thought but only decreased for one of the trials.

[8.2] Were your expectations from Question 6.1 met? Explain, using numerical results.

My predictions for 6.1 were almost exactly what I expected except for one area. I thought that I would have saw an increase for the Chthamalus barnacles on day 2 there were 4 and then on day 14 there were 13. The part that did not met my expectations was I did not see a small decrease in the number of both species towards the end. Only on the first the sample on day 12 t day 4 saw a small decease of 1 individual of each species. But for the second trial there was an increase for each of the species of barnacles fro day 12 to 14. The Chthamalus saw a large increase from 18 to 23. The Semibalanus Saw an increase of 3 to 5.

[8.3] In what ways do you think your results would have been different if you had sampled at a different height on the rock?

Explain.
If I had chosen a different height to conduct my experiment t I would have had much different results depending on the height that I choose. If I decided to chose to conduct this experiment at 1 meter there would have be a much greater abundance of the Semibalanus species and a very small amount of the Chtamalus species found at this point. If choosing this point i think over time the Semibalanis species would have increase rapidly while the Chtamalus will move higher up the rock. I still believe over time each species would see a small decrease in number.

[9.1 ] Revised hypothesis:
The hypothesis that I had made was based of my observations over time watching the simulation over a months time. I don’t think that the hypothesis I made needs to be change because for the most part it was correct the chthamalus was more abundant towards the top of the rock and the Semibalanus was less abundant. Though I did not see a decrease for one of the trails that could be an outlier more trials would have to be run to prove this

Exercise 3:

[1.1] What do you predict will happen to Chthamalus if you exclude Semibalanus from settling on the rock? Explain.

If the Semibalanus Barnalce species was excluded from settling the settling on the rock the Chthamalus Barnalce will inhabit the lower part of the rock with more abundance. This is because they will be able to be less exposed to air and there will be less competition for space.

[2.1] In the absence of Semibalanus, at what height in your plot does Chthamalus settle? Give its distribution range in meters.
When excluding the Semibalanus for the rack face the Chthamalus began to settle down toward the bottom of the rock and away from the top of the rock I saw that the Chthamalus barnacle was distributed from about 0 meters to 4.5 meters.

[2.2] Did you predict correctly? Explain.
The prediction I made was correct the Chthamalus barnacles did start to move to the lower part of the rock face also there was more of an abundance of the barnacle too.

[3.1] Based on your hypothesis, do you predict that Semibalanus is capable of overgrowing and killing Chthamalus? Explain.
Based on my hypothesis I do believe that the Semibalanus barnacle is capable of overgrowing and killing the Chthamalus barnacle. I think this because the when both barnacle species inhabited the same rack face there was a clear separation with Semibalanus abundant on the bottom and Chthamalus abundant on the top

[ 5.1 ] Is Semibalanus capable of overgrowing and killing Chthamalus? Explain.
The Semibalanus are capable of overgrowing and killing the Chthamalus Barnalces. The Chthamalus that were pick would fall off of the rock face in around 1-2 days and the Semibalanus barnacle would become more plentiful over time taking the Chthamalus spots.

[ 5.2 ] Did you predict correctly? Explain.
Yes my prediction was correct the Chthamalus flourished and were very abundant when the Semibalanus barnacle was not present on the rock face. I came to this conclusion because the semibalanus had to have been affecting the chthamalus in some sort way so they cause occupy the lower portion of the rock face

[ 7.1 ] Based on your hypothesis, what do you predict will happen if you transplant a group of Semibalanus to a section of rock in the 1.5–2.5m range, with Chthamalus present?
If the Semibalanus is transplanted to the range of 1.5m to 2.5m while the Chthamalus is present, I believes that the Semibalanus will be a better competitor for the area and over grow the Chthamalus causing them to fall off.

[ 8.1 ] What happened to the transplanted barnacles?
The results of the experiment show that the Semiblannus barancles took over and overgrew the Chthamalus barnacle in the 1.5-2.5 meter range.

The Chthamalus branacles fell off of the rack face and the Semibalanus rock became much more plentiful in that area of the rock.

[ 8.2 ] Did you predict correctly? Explain.

Yes my prediction was correct this is because the Semibalanus barnacle species overgrew and killed off the Chthamalus barnacle species becoming less abundant. The Semibalanus barnacles that were transplanted became more abundant.

[ 9.1 ] Based on your hypothesis, if you cleared an area in the center of the rock face, do you predict that Semibalanus will settle in the new open space (i.e., will any land and attach to the rock in that space)? Why or why not?

I believe that the Semibalanus will inhabit the open area of the rock and out compete the Chthamalus for the open area. I think this because the Semibalanus species seems to be the better competitor of the two.

[ 9.2 ] Based on your hypothesis, if any Semibalanus do settle in the new open space, do you predict that they would persist there (i.e., stick around for a while)?

Explain.
Based on my hypothesis I believe if a few attach to the rock they will not occupy the area for a long time. The Semibalanus species will move to where the Chtamalus barnacles are. I think this will be the result because it seem that the semibalanus rock grow on the Chthamalus they always seem to be competing with them.

[ 11.1 ] What did you observe?
While observing the simulation I saw that a few Semibalanus attached to the empty rock but did not stay in the space for long. In the same space some of the Chhamalus attached and the Semibalanus attached to them and over grew them. The Semibalanus barnacle did not stay in the open spot on the rock face for long.

[ 11.2 ] Did you predict correctly? Explain.
My prediction was correct. I said that the only a small amount of the Semibalanus barnacles would inhabit the empty space on the rock but they wouldn’t stay there for very long. Also that they would move to the areas where the Chthamalus occupied which they did and took over and over grew the area.

[ 13.1 ] Revised hypothesis:
My revised hypothesis I think that the reason behind the barnacle distribution on the rock face is the way it is, is because the Semibalanus is very competitive and like to be lower on the rock face. The reason the Chthamalus species is not found there is because when they do attach to the lower part of the rock the Semibalanus over grow and kill them off. This is why the Chthamalus barnacles move higher on the rock for survival to avoid the Semibalanus barnacles

Exercise 5:

[1.1] What do you observe about the distribution of Nucella on the rock face? Be as specific as possible.
After careful observation it looks like the Nucella are allocated at the bottom of the rock face and stay submerged not going above the water line. The Snails only seem to feed on the barnacles that re found below the water line. AS the tide cahges it also seem that the Nucella move up and down with it a little bit.

[1.2] How is the distribution of barnacles different in the presence of Nucella than it was when Nucella was absent?
The distribution of the barnacles is very different than it was before. While the Nucella is not around the barnacle population seems to be very abundant. When the Nucella is present on the rock face there are less barnacles. The abundance of the Semibalanus barnacle goes down while the Chthamalus species seems to have the same amount of abundance higher on the rock. Also few of the Semibalanus barnacles move high up the rock face to try and move out of the snails reach because they are feeding on them.

[1.3] Develop and present one or two hypotheses to explain your observations:
I think that the Nucella snail can only survive under water watching the simulation none of the snails ever went about the water line to feed on the Semibalanus. The snails only move up and down with the tides.
Secondly I predict that the Nucella snails’ food of choice is the Semibalanus Barnacles over the Chthamalus species this is because when removing the Semibalanus barnacales from the rock face the snails do not seem to eat the Chthamalus species and the baranacles take over the rock face. Also when the snails are present with the Semibalanus there will be much less of that barnacle species.