ABSTRACT:
This paper focuses on the strength of Golden Orb Weaver (Nephila clavipes) silk. Furthermore, this research is dedicated to scientifically finding the root of variation in it’s incredible strength with an ultimate goal of using the silk as a sustainable resource in lue of cattle ranching. While the research into the strength of this species silk has spanned over a decade for the Forman RainForest Project, the extreme variability lends itself to monitoring atmospheric condition such as barometric pressure and temperature at the time of silking each spider.
INTRODUCTION:
The 2018 Spider Silk Team is led by Wendy Welshans, who is assisted by Jason Epstein, a student researcher. The Spider Silk Team has a long history, which started in 1997 as an “accident” when a student silked a Golden Orb Weaver using nothing but his hands and a coke bottle! The program has since evolved to possess two groundbreaking patents to its name as well as becoming the life’s work of Wendy Welshans.
The Nephila Clavipes, common name Golden Orb Weaver, is native to the southern states in the United States of America as well as Latin America. In fact, it is heavily present in Costa Rica, where the majority of the team’s research is done. Spider silk has many positive qualities: it does not cause immune responses when implanted in the human body– meaning the silk could be used for artificial tendons, tissue scaffolding, or even nerve regrowth; the Nephila’s silk is at least three times stronger than Kevlar, and more elastic– meaning silk could be used as ballistics protection (Cheryl Hayashi, 2010). To further attest to its strength, in 2017, the Spider Team conducted tensile strength testing of spider silk in 250 strand bundles, which are still functionally weightless but have an average of 6.21 Newtons, attesting to its strength.
The overall goal of the Spider Team, besides carefully documenting the amazing properties of one of the strongest natural fibers of the world, is to create a sustainable resource in the tropics of the rainforest that can replace cattle ranching. Harvesting spider silk would utilize land that would otherwise need to be destroyed. The Nephila spider must live in its natural habitat to produce quality silk. The flora in its home, however, is a veritable treasure trove as well. Interestingly, almost 25% of prescription drugs are made using ingredients derived from plants (James A. Duke, 1997), and yet only 1% of plants in the most biodiverse area on earth have been studied. Preserving the rainforest allows for the study of potential life-saving drugs. Adoption of silking gives access to a valuable animal product as well as flora that can be worth more than gold.
The Forman Rainforest Project had its first official expedition in the spring of 1992. A year later in 1993, the arachnid project was introduced where student researchers studied Argiope spiders as well as the Golden Orb Weaver (Nephila Clavipes). Originally, the arachnid project focused on studying web anatomy and its construction. It was not until Bryan Sullivan (arachnid project 1997) and the “coke bottle incident” did spider silk itself pique interest: Bryan was handling a golden orb weaver when it laid a sticky disc– a sticky glob of silk that a spider drops to anchor its silk line– on Bryan’s hand and continued to let out dragline, the strongest type of silk the spider produces; Bryan started to wrap the silk around a coke bottle and noticed its incredible strength. It would not be until 2002 that the Forman Spider Team was officially founded.
METHODS & MATERIALS:
Once the team lands in Costa Rica and everything is settled, a trek to El Plastico commences. The Spider Team collects the Nephila Clavipes in transit; the Nephila clavipes is plentiful in the area. The method employed in capturing the spiders resembles the hand placement one has in order to make a shadow puppet of a crocodile. A team member swiftly closes their hands around the spider. An important note is that the researcher should not be concerned about disturbing the web when apprehending the spider. Another thing to note is when collecting the spiders, the researcher needs only target the females, which are easily identified because they are much bigger than the males, of which there is usually one on the web. After apprehending the spider, the researcher simply traps them in a bag, typically the Spider Team uses an onion bag acquired in town. One should not worry about multiple spiders in the bag cannibalizing each other. It has has occurred that in the bag, one spider has eaten another, but they have been rare occurrences.
Once the team arrives at El Plastico, it is important to immediately set the spiders in their habitat. At the El Plastico basecamp, there is a permanent habitat for the spiders constructed out of wood. It is simply open squares situated vertically. After a team member puts a spider in its own box, its instincts will take over and it should set up a web in that location without any further encouragement. A small note is that the male Nephila clavipes and smaller parasitic spiders will appear in the webs over time; however, this is normal. Mapping all the female spiders in the constructed habitat will be one of the most important tasks to set up the silking operation. Mapping allows to identify all of the spiders and where they are situated. It is important to record which spider was silked and at what time. The time of day and weather conditions at the time can greatly affect the silk quantity and quality. Also, the record is important because oversilking a spider can cause distress or even kill her, not to mention affecting the quality of silk.
This described method of silking should be observed closely, as this procedure has been shaped after almost two decades of the Spider Team’s trial and error.
- The first step of silking is removing the female spider from her web. It is important not to disturb the web. The method used is affectionately called the “Welshans’ Cage Method”. The researcher hovers their hand in front of a web, slowly moving it downward towards the spider. The Nephila’s instinct is to travel upwards, which is used to our benefit. The spider should attempt to travel over the researcher’s hand, it is at this point that the hand is gently closed around the spider. The Nephila clavipes is not aggressive, and will only bite if pinched or handled roughly. That being said, if bitten, the only effect will be local redness and swelling.
- The Nephila should be supported on the back of the hand, prompting her to lay a sticky disc– a type of silk used to anchor their dragline– in the hand of the handler. It is important to immediately place the sticky disc around the silkinator’s wheel. Using two hands, the handler should move their hands in a waterfalling motion, which tricks the spider in to thinking it is falling, thus stimulating it to continue to let out its silk.
- A second researcher should turn the silkinator’s crank. A bike odometer is used to count the number of rotations the wheel has made, which should under no circumstances exceed 350 in order not to overtax the spider. Once 350 rotations has been reached,or the spider stops silking on its own, it is returned to its own web. It is important not to directly handle the silk on the wheel, but to use stainless steel probes so as not to leave oils from the skin on the silk. The current version of the silkinator features collapsible rods, which makes removal much easier. The silk sample should be labeled and tested for strength in current atmospheric conditions.
DISCUSSIONS:
RAW DATA:
Note: there are three distinct data tables from the years of 2016, 2017, 2018, this is due to the different organizational tendencies and goals specific to each team, methods and materials were not affected by this, every year tensile strength, barometric pressure, and temperature were recorded.
Date |
Time |
Temp. |
Humidity (%) |
Rainfall |
Wind
D. |
Spider Name/ # |
# of rotations |
Amount Silked |
Color
of
silk |
Strength (N) |
B. Press |
Strand Strength |
|
|
3-2 |
11:08 |
80.7 |
57.50% |
|
NE LGT |
TEST/Firstie |
300 |
250 |
Golden Straw |
5.37 |
28.11 |
0.0179 |
|
|
3-2 |
12:08 |
81.5 |
58.4 |
|
NE LGT |
1/Phyllis |
184 |
153.33 |
Summer time |
4.407 |
28.1 |
0.023951087 |
|
|
3-2 |
12:11 |
81.5 |
57.4 |
|
NE LGT |
2/ Patrica |
280 |
233.33 |
Golden Straw |
5.221 |
28.1 |
0.018646429 |
|
|
3-2 |
14:04 |
80.9 |
59.7 |
|
N LGHT |
3/ Pricilla |
296 |
246.66 |
Sunshine |
13.05 |
28.01 |
0.044087838 |
|
|
3-2 |
4:18 |
80.6 |
60.4 |
|
N LGHT |
4/Treasre |
187 |
155.56 |
Tamed Lion |
5.25 |
28.01 |
0.028074866 |
|
|
3-2 |
14:38 |
79.7 |
62.8 |
|
N LGT |
5/ Spidey |
227 |
190 |
Define |
2.414 |
28 |
0.010634361 |
|
|
3-2 |
14:52 |
77.7 |
69 |
|
N LGT |
6/Biggie Smallz |
240 |
200 |
Lion |
9.201 |
27.99 |
0.0383375 |
|
|
3-2 |
15:12 |
77.3 |
67.8 |
|
N LGT |
7/ Carmen |
70 |
58.33 |
Lemon |
BOT |
28 |
|
|
|
3-2 |
15:25 |
77.3 |
68 |
|
LGHT&VAR |
8/Betsy |
268 |
223 |
Neptune |
5.407 |
28 |
0.020175373 |
|
|
3-2 |
15:45 |
76.6 |
70 |
|
NE LGHT &VAR |
9/ Urcilla |
156 |
130 |
Sunlit Mesa |
BOT |
28.01 |
|
|
|
3-2 |
16:04 |
76.6 |
70.1 |
|
N LGHT&VAR |
10/Harry |
321 |
267.5 |
Golden Straw |
4.461 |
28 |
0.013897196 |
|
|
3-2 |
16:24 |
76.4 |
71.1 |
|
N LGT&VAR |
11/Budy |
162 |
135 |
Melted Caramel |
6.677 |
28.01 |
0.041216049 |
|
|
Date |
Time |
Temp. |
Humidity (%) |
Rainfall |
Wind
D. |
Spider Name/ # |
# of rotations |
Amount Silked |
Color
of
silk |
Strength (N) |
B. Press |
|
|
|
3-2 |
16:49 |
76.4 |
73 |
|
N LGT&VAR |
12/trouble |
77 |
64 |
Starlight |
0.388 |
28.01 |
0.005038961 |
|
|
3-3 |
9:55 |
77.9 |
70.3 |
|
E |
Agnes |
283 |
235.8333333 |
School Days |
9.572 |
28.9 |
0.033823322 |
|
|
3-3 |
10:00 |
81.6 |
61.9 |
|
E |
Dumpling |
124 |
103.3333333 |
Lemon |
0.66 |
28.1 |
0.005322581 |
|
|
3-3 |
10:06 |
82.7 |
59.4 |
|
None |
Marge |
211 |
175.8333333 |
Sunlit Mesa |
0.47 |
28.09 |
0.002227488 |
|
|
3-3 |
10:22 |
86.5 |
61.8 |
|
None |
Katy |
256 |
213.3333333 |
Lemon |
8.36 |
28.09 |
0.03265625 |
|
|
3-3 |
10:47 |
83.4 |
58.4 |
|
None |
Rose |
263 |
219.1666667 |
Golden Straw |
7.81 |
28.08 |
0.029695817 |
|
|
3-3 |
10:56 |
83.8 |
58.7 |
|
None |
Madam |
225 |
187.5 |
Golden Straw |
10.21 |
28.08 |
0.040039216 |
|
|
3-3 |
11:20 |
84.3 |
58.3 |
|
None |
Biggie Smallz |
325 |
270.8333333 |
Neptune |
9.2 |
28.07 |
0.028307692 |
|
|
3-3 |
11:38 |
87.6 |
54.5 |
|
E |
Carmel |
310 |
258.3333333 |
Golden Straw |
6.41 |
28.06 |
0.020677419 |
|
|
3-3 |
11:43 |
88.8 |
53.7 |
|
E |
Harry |
215 |
179.1666667 |
Honeycomb |
6.48 |
28.05 |
0.030139535 |
|
|
3-3 |
12:06 |
84.5 |
61.1 |
|
NE |
Betsy |
191 |
159.1666667 |
Lemon |
7.93 |
28.04 |
0.041518325 |
|
|
3-3 |
13:47 |
83.4 |
61.8 |
|
E |
Phoebe |
0 |
0 |
n/a |
0 |
27.99 |
|
|
|
3-3 |
13:49 |
83.4 |
61.8 |
|
None |
Pricilla |
219 |
182.5 |
Sunny |
10.7 |
27.99 |
0.048858447 |
|
|
3-3 |
14:05 |
85.3 |
58.1 |
|
|
Patricia |
233 |
194.1666667 |
Lemonade |
7.03 |
27.99 |
0.036806283 |
|
|
3-3 |
14:15 |
84.7 |
59.3 |
|
|
Lourde |
230 |
191.6666667 |
School Days |
8.25 |
27.98 |
0.035869565 |
|
|
3-3 |
14:35 |
84.9 |
58.1 |
|
|
Valencia |
220 |
183.3333333 |
Sunny |
3.25 |
27.97 |
0.014772727 |
|
|
3-3 |
14:48 |
84.7 |
58 |
|
|
Harry |
280 |
233.3333333 |
Bit of Sunshine |
6.48 |
27.97 |
0.023142857 |
|
|
3-3 |
18:04 |
75.3 |
75.1 |
|
|
Fiona |
100 |
83.33333333 |
Sunny |
3.15 |
28.02 |
0.0315 |
|
|
3-3 |
18:07 |
75.3 |
75.1 |
|
|
Vicki |
250 |
208.3333333 |
Lemonade |
13.72 |
28.02 |
0.05488 |
|
|
3-4 |
9:12 |
79.5 |
70 |
|
none |
Donna |
180 |
150 |
Sunny |
8.717 |
28.09 |
0.048427778 |
|
|
3-4 |
9:30 |
80.9 |
69.3 |
|
|
Wendy |
170 |
141.6666667 |
Lemonade |
2.986 |
28.09 |
0.017564706 |
|
|
3-4 |
9:43 |
81.3 |
65.3 |
|
|
Situation |
87 |
72.5 |
Sunny |
2.068 |
28.09 |
0.023770115 |
|
|
3-4 |
9:51 |
82.5 |
68.2 |
– |
– |
stitch |
103 |
85.83333333 |
Sunny |
4.027 |
28.09 |
0.039097087 |
|
|
3-4 |
10:01 |
82.7 |
64.1 |
|
– |
Dish Net |
40 |
33.33333333 |
MoonChina |
0.232 |
28.09 |
0.0058 |
|
|
3-4 |
10:09 |
82 |
66.4 |
|
– |
Sandy |
347 |
289.1666667 |
Moon China |
10.11 |
28.09 |
0.029135447 |
|
|
3-4 |
10:21 |
81.3 |
66.5 |
– |
– |
Black Betty |
169 |
140.8333333 |
Honeycomb |
5.763 |
28.09 |
0.034100592 |
|
|
3-4 |
10:30 |
80.6 |
67.5 |
– |
– |
Steve |
274 |
228.3333333 |
Honey comb |
3.191 |
28.08 |
0.011645985 |
|
|
3-4 |
14:26 |
80 |
72.4 |
– |
– |
Welts |
228 |
190 |
Honey Comb |
4.031 |
28.01 |
0.017679825 |
|
|
3-4 |
14:58 |
75.6 |
84.2 |
– |
– |
Clariz |
125 |
104.1666667 |
Golden straw |
3.667 |
28.01 |
0.029336 |
|
|
3-4 |
15:05 |
75.6 |
84.2 |
– |
– |
Soldier |
200 |
166.6666667 |
Golden straw |
3.959 |
27.89 |
0.019795 |
|
|
3-4 |
15:12 |
81 |
77.6 |
– |
– |
Staniel |
260 |
216.6666667 |
Lemonade |
5.329 |
27.89 |
0.020496154 |
|
|
3-4 |
15:24 |
85.9 |
71 |
– |
– |
Carmel |
262 |
218.3333333 |
Lemonade |
10.03 |
28.01 |
0.038282443 |
|
|
3-4 |
15:57 |
79.6 |
76.5 |
– |
– |
Patricia |
250 |
208.3333333 |
Lemonade |
13.29 |
27.91 |
0.05316 |
|
|
3-4 |
16:07 |
82.1 |
77.6 |
– |
– |
Betsey |
250 |
208.3333333 |
School Days |
BOT |
27.91 |
|
|
|
3-4 |
16:18 |
82.1 |
77.6 |
– |
– |
Biggie Smallz |
250 |
208.33 |
Golden Straw |
|
27.91 |
|
|
|
3-5 |
11:55 |
84.6 |
61.3 |
|
|
Buddy |
107 |
89.16666667 |
Lemonade |
5.98 |
28.09 |
0.05588785 |
|
|
3-5 |
12:04 |
86.9 |
61.6 |
|
|
Biggie Smallz |
245 |
204.1666667 |
Golden Straw |
2.54 |
28.09 |
0.010367347 |
|
|
3-5 |
12:18 |
86.4 |
63.9 |
|
|
Carmel |
150 |
125 |
School Days |
6.17 |
28.08 |
0.041133333 |
|
|
3-5 |
12:26 |
87.5 |
61.3 |
|
|
Betsy |
250 |
208.3333333 |
Golden Straw |
9.94 |
28.07 |
0.03976 |
|
|
3-5 |
16:17 |
78.3 |
77.3 |
– |
– |
Fiona |
193 |
160.8333333 |
Moon China |
12.61 |
28.04 |
0.065336788 |
|
|
3-5 |
16:36 |
77 |
77.2 |
– |
– |
Donna |
427 |
355.8333333 |
Honey comb |
BOT |
27.95 |
|
|
|
3-5 |
16:53 |
77 |
77.2 |
– |
– |
Pricilla |
225 |
187.5 |
Banana Bunch |
6.5 |
27.95 |
0.028888889 |
|
|
3-5 |
17:00 |
76.6 |
77.6 |
– |
– |
Clariz |
320 |
266.6666667 |
Bone China |
10.29 |
27.96 |
0.03425 |
|
|
3-5 |
7:15 |
76.5 |
77 |
– |
– |
Chocolate con leche |
213 |
177.5 |
Bone China |
1.439 |
27.96 |
0.005347418 |
|
|
|
|
|
|
|
|
|
|
987.5 |
787.5 |
1775 |
|
|
|
|
Date |
Time |
Temp. |
Humidity (%) |
Rainfall |
Wind
D. |
Spider Name/ # |
# of rotations |
Amount Silked |
Color
of
silk |
Strength (N) |
B. Press |
|
|
|
3-5 |
17:37 |
83.2 |
75.8 |
– |
CALM |
35/staniel |
296 |
246.6666667 |
Honey comb |
|
27.96 |
|
|
|
3-5 |
18:07 |
83.2 |
75.8 |
|
– |
36/Mikey |
130 |
108.3333333 |
Honey comb |
1.913 |
27.96 |
0.014715385 |
|
|
3-6 |
11:48 |
85.3 |
56.2 |
– |
– |
34/ Soldier |
250 |
208.3333333 |
Sunny |
7.569 |
27.98 |
0.030276 |
|
|
3-6 |
11:57 |
85.3 |
56.2 |
– |
– |
33/Clariz |
179 |
149.1666667 |
Sunny |
5.054 |
27.98 |
0.028234637 |
|
|
3-6 |
12:06 |
88.8 |
56.2 |
– |
– |
35/Staniel |
142 |
118.3333333 |
Bone China |
2.486 |
27.98 |
0.017507042 |
|
|
3-6 |
12:18 |
88.3 |
59 |
– |
– |
28/Sandy |
169 |
140.8333333 |
Sunny |
10.01 |
27.98 |
0.059230769 |
|
|
3-6 |
15:06 |
82.8 |
66 |
|
|
31, Steve |
118 |
98.33333333 |
Bone China |
1.89 |
28.03 |
0.016016949 |
|
|
3-6 |
15:35 |
81.7 |
67.4 |
|
|
37, Debbie |
250 |
208.3333333 |
Golden Straw |
8.51 |
28.04 |
0.03404 |
|
|
3-6 |
15:37 |
81.9 |
67.4 |
|
|
36, Mikey |
250 |
208.3333333 |
Golden Straw |
4.12 |
28.04 |
0.01648 |
|
|
3-6 |
16:00 |
81.9 |
67.4 |
|
|
39, Becky |
250 |
208.3333333 |
Boon China |
6.829 |
28.04 |
0.027316 |
|
|
3-6 |
16:25 |
81.9 |
67.4 |
|
|
2/Patrcia |
250 |
208.3333333 |
Golden Straw |
6.647 |
28.04 |
0.026588 |
|
|
3-6 |
17:16 |
80.3 |
72.6 |
|
|
1/Phyllis |
273 |
227.5 |
Golden Straw |
9.044 |
28.05 |
0.033128205 |
|
|
3-6 |
17:26 |
81.9 |
72.6 |
|
|
3/Pricilla |
36 |
30 |
Golden Straw |
1.3 |
28.05 |
0.026111111 |
|
|
3-6 |
17:38 |
85.8 |
73 |
|
|
21/Velencia |
356 |
296.6666667 |
Golden Straw |
14.8 |
28.05 |
0.041573034 |
|
|
3-6 |
18:00 |
85.8 |
73 |
|
|
10/ Harry |
103 |
85.83333333 |
Golden Straw |
1.807 |
28.05 |
0.017543689 |
|
|
3-6 |
18:08 |
84 |
72 |
|
|
24/Wendy |
136 |
113.3333333 |
Golden Straw |
4.8 |
28.04 |
0.035294118 |
|
|
3-8 |
17:30 |
|
|
|
|
1/ RA |
202 |
168.3333333 |
Golden Straw |
7.159 |
27.48 |
0.035440594 |
|
|
3-8 |
18:08 |
73.9 |
83 |
– |
– |
1/Sassy Frass |
215 |
179.1666667 |
Golden Straw |
9.15 |
27.48 |
0.04255814 |
|
|
3-8 |
18:15 |
74.4 |
81.1 |
|
|
2/Kristy |
223 |
185.8333333 |
Golden Straw |
14.16 |
27.48 |
0.063497758 |
|
|
3-9 |
9:10 |
75.2 |
78.5 |
– |
– |
3/Dureesh |
158 |
131.6666667 |
Bone China |
2.506 |
27.54 |
0.015860759 |
|
|
3-9 |
10:00 |
77 |
75.5 |
|
|
4/Tyrome |
214 |
178.3333333 |
Sunny |
1.887 |
27.54 |
0.008817757 |
|
|
3-9 |
10:10 |
77 |
75.1 |
|
|
5/Tinky |
206 |
171.6666667 |
Bone China |
0.067 |
27.54 |
0.000325243 |
|
|
3-9 |
10:20 |
77 |
75.1 |
|
|
6/Dirty mike |
371 |
309.1666667 |
Bone China |
0.222 |
27.53 |
0.000598383 |
|
|
3-9 |
10:30 |
77 |
75.1 |
|
|
7/Adam |
114 |
95 |
Bone China |
0.437 |
27.53 |
0.003833333 |
|
|
3-9 |
10:40 |
78 |
74.2 |
|
|
8/Caroline |
270 |
225 |
Bone China |
1.197 |
27.53 |
0.004433333 |
|
|
3-9 |
15:38 |
76.6 |
76.3 |
|
|
9/Chris |
250 |
208.3333333 |
Spotlight |
10.5 |
27.44 |
0.042 |
|
|
3-9 |
15:51 |
76.6 |
76.3 |
|
|
10/SamuEL |
250 |
208.3333333 |
Bone China |
2.472 |
27.44 |
0.009888 |
|
|
3-9 |
16:00 |
77.9 |
77.3 |
|
|
11/TaiChai |
250 |
208.3333333 |
Spotlight |
5.692 |
27.43 |
0.022768 |
|
|
3-9 |
5:20 |
75.3 |
76.7 |
|
|
12/Party Pooper |
427 |
355.8333333 |
Golden Straw |
23.92 |
27.47 |
0.056018735 |
|
|
3-9 |
18:00 |
75.3 |
76.7 |
|
|
13/ Sean |
333 |
277.5 |
Spotlight |
7.27 |
27.47 |
0.021831832 |
|
|
3-9 |
18:15 |
75.3 |
76.7 |
|
|
14/ditsy |
397 |
330.8333333 |
Golden Straw |
10.92 |
27.47 |
0.027506297 |
|
|
3-10 |
9:05 |
70.3 |
77.9 |
|
|
15/ Charles (before soak) |
100 |
83.333 |
Golden Straw |
3.848 |
27.56 |
STOP |
|
|
3-10 |
9:15 |
70.3 |
77.9 |
|
|
15/Charles (after soak) |
100 |
83.33333333 |
Golden Straw |
2.848 |
27.56 |
|
|
|
3-10 |
9:20 |
77.3 |
71.9 |
|
|
16/lindenberg (wet) |
100 |
83.33333333 |
bone china |
4.245 |
27.56 |
|
|
|
3-10 |
9:25 |
77.9 |
71.8 |
|
|
16/lindenberg(dry) |
100 |
83.33333333 |
bone china |
1.615 |
27.56 |
|
|
|
3-10 |
9:30 |
78 |
71.6 |
|
|
17/Krinky (soaked) |
100 |
83.33333333 |
Golden Straw (lemonade before spray) |
2.209 |
27.56 |
|
|
|
3-10 |
9:35 |
78.4 |
71.6 |
|
|
17/ Kinky (dry) |
100 |
83.33333333 |
Spotlight |
0.827 |
27.56 |
|
|
|
3-10 |
9:41 |
78.9 |
71.6 |
|
|
18/George (Soaked) |
100 |
83.33333333 |
Sunny |
3.016 |
27.56 |
|
|
|
3-10 |
9:50 |
79.7 |
68.7 |
|
|
18/ George (dry) |
100 |
83.33333333 |
Sunny |
2.48 |
27.56 |
|
|
|
3-10 |
10:00 |
79.7 |
68.7 |
|
|
19/Jimmy |
250 |
208.3333333 |
|
|
27.56 |
|
|
|
3-10 |
|
|
|
|
|
|
|
0 |
|
|
|
|
|
|
3-10 |
|
|
|
JUAN |
4166 feet |
|
|
|
|
|
|
|
|
|
3-10 |
|
|
|
|
|
|
|
|
|
|
16788.373 |
|
|
|
3-10 |
|
|
|
|
|
|
|
|
|
|
19850.373 |
|
|
|
3-10 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
3-10 |
|
|
|
|
|
|
|
|
|
|
24016.373 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
session |
timestamp |
temp_c |
dew_point_c |
spider |
location |
Fiber type |
Strand count |
session_time |
rotations |
k_lux |
Baro |
newtons |
strand_strength_newtons |
outlier |
1 |
2017-03-02 11:25:00 |
25.5 |
N/A |
21 |
|
|
|
N/A |
145 |
6.74 |
21.02 |
7 |
0.04827586207 |
|
3 |
2017-03-02 12:30:00 |
25.5 |
N/A |
30 |
|
|
|
N/A |
231 |
1.5 |
21.02 |
9.1 |
0.03939393939 |
|
4 |
2017-03-02 12:45:00 |
25.6 |
N/A |
20 |
|
|
|
0:05:26 |
211 |
1.5 |
27.97 |
17.5 |
0.08293838863 |
|
5 |
2017-03-02 17:25:00 |
25.6 |
17.8 |
22 |
|
|
|
0:09:12 |
229 |
0.1 |
27.96 |
19.8 |
0.0864628821 |
|
6 |
2017-03-03 9:52:00 |
25.2 |
18.8 |
14 |
|
|
|
0:03:27 |
250 |
7 |
28.07 |
2.49 |
0.0092 |
|
7 |
2017-03-03 11:25:00 |
23.2 |
19 |
8 |
|
|
|
0:03:35 |
269 |
4.8 |
28.04 |
13.2 |
0.04795539033 |
|
9 |
2017-03-03 16:00:00 |
24.23 |
18.7 |
26 |
|
|
|
N/A |
|
0 |
N/A |
8 |
|
o |
10 |
2017-03-03 17:17:00 |
23.5 |
18.6 |
6 |
|
|
|
0:06:20 |
350 |
0 |
29.97 |
1.5 |
0.02285714286 |
|
12 |
2017-03-04 9:16:00 |
23.9 |
20.6 |
10 |
|
|
|
0:02:22 |
130 |
0.1 |
28.09 |
2.1 |
0.01615384615 |
|
13 |
2017-03-04 9:57:00 |
25.7 |
20.8 |
4 |
|
|
|
0:03:22 |
258 |
0.2 |
28.09 |
6.9 |
0.02596899225 |
|
14 |
2017-03-04 10:30:00 |
25.8 |
19.2 |
21 |
|
|
|
0:03:38 |
244 |
3.6 |
28.09 |
6.4 |
0.0262295082 |
|
15 |
2017-03-04 10:50:00 |
25.2 |
21.1 |
17 |
|
|
|
0:03:12 |
250 |
2 |
28.09 |
6.8 |
0.0248 |
|
18 |
2017-03-04 16:56:00 |
27 |
19.9 |
30 |
|
|
|
0:02:51 |
162 |
0.4 |
27.97 |
8.7 |
0.04938271605 |
|
20 |
2017-03-06 11:04:00 |
22.8 |
19.5 |
34 |
B |
|
|
N/A |
50 |
1.1 |
27.54 |
2.9 |
0.02858 |
|
21 |
2017-03-06 11:39:00 |
24.3 |
19.9 |
44 |
L |
|
|
N/A |
75 |
8.7 |
27.51 |
2.8 |
0.03733333333 |
|
22 |
2017-03-06 12:10:00 |
23.4 |
19.8 |
38 |
F |
|
|
N/A |
72 |
0.1 |
27.51 |
2.769 |
0.03101388889 |
|
23 |
2017-03-06 12:22:00 |
23.4 |
19.8 |
38 |
F |
|
|
N/A |
72 |
0.1 |
27.51 |
3.34 |
0.03101388889 |
|
24 |
2017-03-06 12:31:00 |
23.4 |
19.8 |
38 |
F |
|
|
N/A |
72 |
0.1 |
27.51 |
2.248 |
0.03101388889 |
|
25 |
3/6/2017 12:50:00 |
23.3 |
19.4 |
39 |
G |
|
|
N/A |
60 |
0.1 |
27.51 |
1.2 |
0 |
|
26 |
2017-03-06 14:40:00 |
20.5 |
18.8 |
42 |
J |
|
|
N/A |
244 |
0.6 |
27.49 |
4.192 |
0.01668032787 |
|
27 |
2017-03-06 16:13:00 |
23.9 |
19.7 |
40 |
H |
|
|
N/A |
246 |
0.1 |
27.45 |
9.6 |
0.03902439024 |
|
28 |
2017-03-06 16:45:00 |
23.6 |
19 |
43 |
K |
|
|
N/A |
52 |
N/A |
27.45 |
1.186 |
0.01032692308 |
|
29 |
2017-03-07 9:23 |
23.5 |
20.7 |
33 |
A |
|
|
N/A |
176 |
N/A |
27.57 |
4.202 |
|
|
30 |
03-07-2017 9:51 |
23.5 |
20.7 |
35 |
C |
|
|
N/A |
141 |
N/A |
27.56 |
3.666 |
|
|
31 |
2017-03-07 10:17 |
24.5 |
21.7 |
37 |
E |
|
|
N/A |
213 |
N/A |
27.55 |
7.579 |
|
|
32 |
3/9/2017 15:00:00 |
——- |
——- |
——- |
——- |
nylon |
1/6 |
——- |
——- |
——- |
N/A |
9.78 |
|
|
32 |
3/8/2017 12:58 |
——- |
——- |
——- |
——- |
wool |
1/4 |
——- |
——- |
——- |
N/A |
4.57 |
|
|
32 |
3/8/2017 20:09 |
——- |
——- |
——- |
——- |
hemp |
1/4 |
——- |
——- |
——- |
N/A |
7.435 |
|
|
32 |
3/7/2017 20:20 |
——- |
——- |
——- |
——- |
kevlar |
1/6 |
——- |
——- |
——- |
N/A |
5.579 |
|
|
32 |
2017-03-08 8:34:00 |
25.7 |
20.2 |
45 |
M |
|
|
|
232 |
0.2 |
27.55 |
10.95 |
0.04719827586 |
|
32 |
3/8/2017 9:30 |
——- |
——- |
——- |
——- |
cotton |
1/33 |
——- |
——- |
——- |
N/A |
9.3 |
|
|
32 |
3/9/17 11:00 |
——- |
——- |
——- |
——- |
Nylon monofilament |
1 |
——- |
——- |
——- |
N/A |
16.4 |
|
|
39 |
3/8/2017 10:07 |
26.1 |
20.3 |
38 |
F |
cotton |
1/33 |
N/A |
250 |
0.2 |
27.56 |
15.07 |
|
|
40 |
3/8/2017 11:55 |
26.2 |
21.7 |
33,44 |
A,L |
Hemp |
1/4 |
|
250 |
2 |
27.51 |
24.072 |
|
No Graph |
41 |
3/8/2017 12:21 |
27.4 |
22.3 |
42 |
J |
Wool |
1/4 |
N/A |
250 |
0.9 |
27.5 |
10.5 |
|
|
43 |
3/8/2017 1744h |
26.7 |
22.1 |
36,45 |
D,M |
Kevlar |
1/6 |
N/A |
250 |
1.4 |
27.47 |
23.85 |
|
|
44 |
3/9/2017 1015 |
26.4 |
20.9 |
33 |
A |
nylon |
1/16 |
N/A |
250 |
2.3 |
27.51 |
8.234 |
|
|
45 |
3/9/2017 1226 |
27.1 |
21.9 |
45,38 |
M,F |
nylon monofilament |
1 |
N/A |
250 |
0.2 |
27.46 |
18.97 |
|
|
46 |
3/9/2017 1256 |
27.7 |
21.8 |
44,32 |
L,J |
cotton |
1/33 |
N/A |
250 |
0.2 |
27.44 |
12.5 |
|
|
48 |
3/9/2017 1721 |
25.6 |
21.3 |
38 |
F |
hemp |
1/4 |
N/A |
250 |
0.3 |
27.41 |
34.07 |
|
|
49 |
3/10/2017 0652 |
N/A |
N/A |
33, 39 |
A,G |
hemp |
1/4 |
N/A |
250 |
N/A |
N/A |
35.75 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Date |
Time |
Baro (inHG) |
Temp (C) |
Humidity |
Wind |
Precip |
Cloud Cover |
Spider Name |
# of Rotations |
Length Silked (cm)(Rounded to Whole #) |
Color |
Force to Break (N) |
Comments |
|
1-Mar-18 |
15:19 |
27.91 |
26.5 |
61.30% |
0 |
0 |
Cumulo Stratus |
Jenny |
250 |
9974 |
B125 |
4.7 |
Cut line twice |
|
1-Mar-18 |
16:12 |
27.93 |
25.9 |
61.40% |
0 |
0 |
Cumulo Stratus |
Jackie |
250 |
9974 |
B114 |
———————— |
Broke while removing from wheel |
|
1-Mar-18 |
17:05 |
27.95 |
24.8 |
63.50% |
0 |
0 |
Cumulo Stratus |
Rachel |
93 |
3704 |
B115 |
———————— |
Appeared lethargic, stopped sinking at 93 rotations error with the attenuator affected tensile testing |
|
2-Mar-18 |
9:00 |
28.07 |
21.5 |
87.10% |
0 |
0 |
Cumulus |
Rachel |
194 |
7740 |
B114 |
———————— |
Human error |
|
2-Mar-18 |
9:18 |
28.04 |
24.1 |
73.40% |
0 |
0 |
Cumulus |
Ariana |
250 |
9974 |
B113 |
4.4 |
|
|
2-Mar-18 |
11:40 |
28 |
25.7 |
62.30% |
0 |
0 |
Cumulus |
Adriana |
250 |
9974 |
B115 |
3.1 |
Tenso forward motion on accident |
|
2-Mar-18 |
12:02 |
———————— |
———————— |
59.40% |
0 |
0 |
Cumulus |
Bella |
125 |
4987 |
B117 |
———————— |
Broke while removing from wheel |
|
2-Mar-18 |
17:26 |
27.95 |
24.2 |
73.90% |
0 |
0 |
Cumulus |
Jenny |
224 |
8937 |
B127 |
7.3 |
Beautiful Gold Color |
|
3-Mar-18 |
9:50 |
28.02 |
26.4 |
65.70% |
0 |
0 |
Cumulus |
Sparkles |
128 |
5147 |
B124 |
3.2 |
4:50 seconds 5 cuts |
|
3-Mar-18 |
10:01 |
28.02 |
26.4 |
70.30% |
0 |
0 |
Cumulus |
Angel |
181 |
7221 |
B123 |
2.9 |
2 cuts |
|
3-Mar-18 |
10:36 |
28 |
27 |
68.10% |
0 |
0 |
Cumulus |
Ariana |
141 |
5625 |
B125 |
2.2 |
4:30 seconds |
|
3-Mar-18 |
16:42 |
27.93 |
25.5 |
71.40% |
0 |
0 |
Cumulo Stratus |
Jane |
170 |
6782 |
B123 |
————————Human error |
no breaks |
|
3-Mar-18 |
17:11 |
27.93 |
25.4 |
69.50% |
0 |
0 |
Cumulo Stratus |
Jackie |
8 |
319 |
———————— |
———————— |
could not even remove web Jackie had not been in her web fir two days, she sat above it in the rafters |
|
3-Mar-18 |
17:21 |
27.93 |
25.6 |
70.90% |
0 |
0 |
Cumulo Stratus |
Ariana |
100 |
3989 |
B125 |
0.4 |
3:10 seconds Silked twice in one day, mistaken for Jenny Johan also broke some strands |
|
3-Mar-18 |
18:00 |
27.95 |
24.8 |
73.60% |
0 |
0 |
Stratus |
Jenny |
185 |
7381 |
B126 |
3.9 |
2 cuts, 4:15 |
|
3-Mar-18 |
20:51 |
28.03 |
22.5 |
82.40% |
0 |
0 |
too dark to see |
Rachel |
148 |
5904 |
———————— |
———————— |
3 cuts, broke on removal |
|
3-Mar-18 |
21:13 |
28.03 |
22.8 |
82.50% |
0 |
0 |
too dark to see |
Bella |
180 |
7181 |
B125 |
3.9 |
no breaks, 3:25, lethargic afterwards |
|
4-Mar-18 |
9:05 |
28.01 |
24.4 |
75.30% |
0 |
0 |
clear sky |
Adriana |
100 |
3989 |
B114 |
1.3 |
cut at 100 on purpose |
|
4-Mar-18 |
9:40 |
27.94 |
26.7 |
60.30% |
0 |
0 |
clear sky |
Annie |
100 |
3984 |
B112 |
1.6 |
Cut once, capped at 100 |
|
4-Mar-18 |
17:50 |
27.45 |
23.9 |
74.20% |
0 |
0 |
———————— |
Jenny |
64 |
2553 |
B132 |
1 |
Cut once, she had already been silken the fourth for teleflex |
|
4-Mar-18 |
18:03 |
27.96 |
23.9 |
74% |
0 |
0 |
Cumulus |
Bella |
74 |
2952 |
———————— |
———————— |
Broke while removing from wheel, tough time sinking |
|
4-Mar-18 |
18:14 |
27.96 |
24 |
73% |
0 |
0 |
Cumulus |
Adriana |
35 |
1396 |
B114 |
———————— |
Too small to test |
|
5-Mar-18 |
6:04 |
28 |
21.3 |
81.70% |
0 |
0 |
Cumulo Stratus |
Jane |
78 |
3112 |
B125 |
2.5 |
one cut |
|
5-Mar-18 |
6:20 |
28 |
20 |
80.60% |
0 |
0 |
Cumulo Stratus |
Angel |
47 |
1875 |
———————— |
1.8 |
possibly put on wrong |
|
5-Mar-18 |
9:15 |
27.94 |
25.6 |
76.80% |
0 |
Yes,
—— |
Cumulus |
Jenny |
75 |
2992 |
B124 |
1 |
Cut once |
|
7-Mar-18 |
19:05 |
27.55 |
19.2 |
86.60% |
0 |
Yes. .5 cm |
Heavy Stratus |
Jolene |
10< |
———————— |
———————— |
———————— |
Very hard time silking, multiple cuts before even reaching ten rotations (Rara Avis) |
|
7-Mar-18 |
19:13 |
27.55 |
18.2 |
86.60% |
0 |
Yes. .5 cm |
Heavy Stratus |
Charlotte |
28 |
1117 |
———————— |
———————— |
Broke while removing from wheel, very difficult to silk, multiple cuts (Rara Avis) |
|
Note: Because this paper looks specifically at tensile strength, barometric pressure, and temperature, a second raw data chart was made isolating spiders, barometric pressure, and average strand strengths of those silk collections. Spiders silked three or more times are highlighted with their own specific color and used in the following data graphs
|
Strand Strength |
Temperature (C) |
Barometric (inHG) |
Patrica |
0.018646429 |
27.5 |
28.1 |
Patricia |
0.036806283 |
29.6 |
27.99 |
Patricia |
0.05316 |
26.44 |
27.91 |
Patrcia |
0.026588 |
27.72 |
28.04 |
|
|
|
|
|
Strand Strength |
Temperature (C) |
Barometric (inHG) |
Pricilla |
0.044087838 |
27.16 |
28.01 |
Pricilla |
0.048858447 |
28.55 |
27.99 |
Pricilla |
0.028888889 |
25 |
27.95 |
3/Pricilla |
0.026111111 |
27.72 |
28.05 |
|
|
|
|
|
Strand Strength |
Temperature (C) |
Barometric (inHG) |
Betsy |
0.020175373 |
25.16 |
28 |
Betsy |
0.041518325 |
29.16 |
28.04 |
Betsy |
0.03976 |
30.83 |
28.07 |
|
|
|
|
|
Strand Strength |
Temperature (C) |
Barometric (inHG) |
Biggie Smallz |
0.0383375 |
25.38 |
27.99 |
Biggie Smallz |
0.028307692 |
29.05 |
28.07 |
Biggie Smallz |
0.010367347 |
30.5 |
28.09 |
|
|
|
|
|
Strand Strength |
Temperature (C) |
Barometric (inHG) |
Carmel |
0.020677419 |
30.88 |
28.06 |
Carmel |
0.038282443 |
29.94 |
28.01 |
Carmel |
0.041133333 |
30.22 |
28.08 |
|
|
|
|
|
Strand Strength |
Temperature (C) |
Barometric (inHG) |
Harry |
0.013897196 |
24.77 |
28 |
Harry |
0.030139535 |
31.55 |
28.05 |
Harry |
0.023142857 |
29.27 |
27.97 |
|
|
|
|
|
Strand Strength |
Temperature (C) |
Barometric (inHG) |
Clariz |
0.029336 |
24.22 |
28.01 |
Clariz |
0.03425 |
24.77 |
27.96 |
Clariz |
0.028234637 |
29.61 |
27.98 |
|
|
|
|
|
Strand Strength |
Temperature (C) |
Barometric (inHG) |
Jenny |
0.0188 |
26.5 |
27.91 |
Jenny |
0.032589286 |
24.2 |
27.95 |
Jenny |
0.021081081 |
24.8 |
27.95 |
Jenny |
0.015625 |
23.9 |
27.45 |
Jenny |
0.013333333 |
25.6 |
27.94 |
TABLES:
STATISTICAL ANALYSIS:
Barometric pressure (inHG) values; 27.91, 27.96, 28.08, 28.04, 27.99, 27.99. 28.05, 27.95.
Barometric Pressure had a difference of .17 from the highest to the lowest value
The Mean value for highest tensile strength in this lab in regards to barometric pressure was 27.99625
The Temperature (celcius) values; 31.55, 26.44, 28.55, 29.16, 25.38, 30.22, 24.77, 24.2
Temperature had a difference of 7.35 degrees from the highest to lowest values
The mean value for highest tensile strength in this lab in regards to temperature was 27.5
For use in abstract??
CONCLUSION:
Though we used the past three years of data, based on our findings, we cannot affirmatively say that barometric pressure or temperature has any obvious effect on the tensile strength of the Nephila clavipes. It is possible that the results were influenced by 2018’s findings, in which prior to this team’s arrival, a cold snap had killed the majority of the resident spiders and presumably induced stress in the surviving ones. Again, while no obvious relationship between barometric pressure, temperature and silk tensile strength was observed, within this study; the average for optimal conditions of silk strength was a barometric pressure of 27.99625, and a temperature of 27.5 degrees Celsius.This paper’s authors used three years, 2016, 2017 and 2018 for data. Spiders that had been silked three times or more, were graphed twice with temperature (in celsius) over strand strength (in newtons). And barometric pressure (inHG) over strength (Newtons). For each spider, we looked at the highest tensile value, and its coinciding temperature and barometric values.
ACKNOWLEDGEMENTS:
A Thank you to all the previous teams for their data gathering and construction of materials and methods,
Bryan Sullivan
Jerry Kersten
Danielle Odell
Brady Rose
John Small
Luke Bornheimer
Rachel Clarkin
Addison Keilty
Megan Blair
Winston Macdonald
Nick Manzella
Zachary Bitan
Ryan Lowe
Jacob Sussman
John Goldstein
Ariel Blum
Lawton Jeffords
Special thanks to Linus Trahair, assistance in data analysis
REFERENCES:
AUTHORSHIP: Wendy L. Welshans, Jason M. Epstein