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How camouflage in crab spider has helped its survival?

1. Stevens, M., & Merilaita, S. (2009). Animal Camouflage: Current Issues And New Perspectives. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1516), 423-427.

This reference talks about the history, definitions, and importance of camouflage in animals as a whole.

2. Théry, M., & Casas, J. (2009). The multiple disguises of spiders: web colour and decorations, body colour and movement. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1516), 471-480.

This reference goes into detail about body color of spiders and in particularly talks about crab spiders. Crab spiders are able to change colors by using their background environment and the color of their prey. The crypsis is said to be \both aggressive and defensive.

3. Thery, M. (2004). Specific color sensitivities of prey and predator explain camouflage in different visual systems. Behavioral Ecology, 16(1), 25-29.

This reference talks about a study done on female crab spiders and their predation habits. The study used chromatic and achromatic contrast to measure the efficiency of female crab spider camouflage. The study consisted of 10 female crab spiders and 10 flowers of Leucanthemum vulgare.

4. Heiling, A. M. (2005). Colouration in crab spiders: substrate choice and prey attraction. Journal of Experimental Biology , 208(10), 1785-1792. This reference talks about the signals animals give off to elicit a response from the receiver. In this study they use an Australian crab spiders called Thomisus spectabilis. This study talks about the colors the pollinator, such as bees, are attracted to. For example, white crab spiders on white flowers are not camouflaged as well as yellow crab spiders on yellow flowers, but the bees are still attracted to the flower, regardless if there is a spider on it.

5. Chittka, Lars. "Camouflage of predatory crab spiders on flowers and the colour perception of bees (Aranida: Thomisidae/Hymenoptera: Apidae)." Entomologia Generalis 25, no. 3 (2001): 181-187. In this reference a species of crab spiders called Misumena vatia is studied. This species can change color from yellow to white and back again. The white spiders have UV absorbing bodies while yellow spiders have UV reflecting bodies. The color perception of the pollinators plays a factor in identifying if there is a spider on the flower.

https://en.wikipedia.org/wiki/Misumena_vatia Suggestions: 1. Maybe give some examples of the types of flowers the spider is found on and going into detail about how the color change happens on a specific flower 2. Maybe also talk about how effective the camouflage of the spider is in catching prey 3. Maybe also talk about studies done the these spiders

The color similarity between the spider and the flower is well matched with a white flower, in particular the Chaerophyllum temulum, compared to a yellow flower based on the spectral reflectance functions.

I decided to add this sentence because I wanted to show how similar the colors were with the spider and flower.

Final Draft Starts Here

Evolutionary Strategies of Crab Spiders Leading to Increased Fitness Spiders first appeared about 400 million years ago and have evolved over time to help them survive. There are around 34,000 species of spiders to date (Coddington 1991). The evolution of spiders can help with studying life histories and evolution of other invertebrates. The study of the evolution of predation habits of spiders can help with studying pest control. Spiders can be used to control an insect population because spiders prey on insects, therefore it is a way of pest control. The pest control can help farmers during agricultural seasons. For example if there is a specific insect which preys on a type of plant farmers can introduce a spider population which eats those insects, therefore controlling the pest population. Also studying the evolution of spider venom can be helpful medically, because some venom can be used to help treat diseases. By studying how venom evolved in spiders scientists can look for specific chemicals in spider venom to help treat diseases. There are many ways in which the evolution of spiders can contribute to the real world. Evolutionary strategies such as camouflage, selection for patches, and the mixture of sexual selection and natural selection have led to success in fitness of crab spiders. A mechanism used by spiders, in particular crab spiders, is camouflage which has helped them survive. In relation to animals, camouflage is used to conceal themselves from other animals. Examples of camouflage are concealing coloration, disruptive, mimicry, and disguise. Concealing coloration camouflage is when animals blend in with their environment concealing themselves. Disruptive camouflage is when there is some type of pattern making it hard for other animals to see the outline of the animal. Mimicry is when an animal mimics another animal. And lastly disguise is when an animal blends itself to the environment through its shape or texture and not by color. Crab spiders change colors according the color of the flower on which it sits and waits for its prey. The crab spiders uses the concealing coloration method of camouflage. Camouflage is one of the evolutionary strategies which has helped in the increased fitness in crab spiders. Crab spiders come in many different species, around 2152, and are found all over the world (Richard Bradley and Steve Buchanan 2012). The most studied and most notable species of crab spiders are the Misumena vatia and Thomisus spectabilis. The Misumena vatia are crab spiders, also known as the Goldenrod spider, is found throughout North America and Europe. The Thomisus spectabilis, also known as the Australian crab spider, is found throughout Australia. These crab spiders change color according to the color of the flower, usually yellow or white, in which it sits and waits to catch prey. The spiders uses a type venom to paralyze their prey and then eats it. Usually the prey are pollinators such as honeybees. The exact process in changing color is not well known, but what is known is the color change is due to transferring some type of liquid pigment to the cuticles (Gabritschevsky 1927). The evolution of camouflage used by the Misumena vatia and the Thomisus spectabilis crab spider species has helped greatly in the survival and fitness of these spiders. Due to Misumena vatia method of camouflage, it is able to focus its energy on growing and reproduction because it does not need to spend energy on finding food like other species of spiders. Crab spiders wait for their prey and lures in their prey allowing the female crab spiders to focus on growing and reproduction. Also by matching its environment, it does not need to focus on escaping from predators. In a study done by Robert Fritz and Douglass Morse, 163 adult crab spiders were measured over 3 years looking at reproductive success of the Misumena vatia. They concluded there was a positive correlation between female weight of the adult Misumena vatia and egg clutch size (Fritz and Morse 1985). The conclusion means the greater the female weighed the more eggs were produced. Thus selection for larger female body size increases reproductive success (Head 1995). According to the studies, Misumena vatia are able to focus its energy on growing and reproduction because of how effective the camouflage conceals the spider from predators. The effectiveness of the camouflage allows the spiders to also not spend energy on finding food. Due to the method of camouflage in Misumena vatia, it has helped increase its survivability and fitness. In the Thomisus spectabilis, the method of camouflage is similar to the Misumena vatia except the Thomisus spectabilis blend in with their environment while being visible to their prey, but not their predators. This species of crab spiders are UV reflective while the flower is UV absorbing creating a contrast between the spider and flower through the eyes of the pollinator (Gawryszewski 2012). The contrast created greatly attracts pollinators such as honeybees. This evolutionary method of camouflage increased the likelihood the crab spiders encountered prey, which in turn effects the fitness of the crab spiders. Due to the increased encounter rate of prey the spiders are able to focus energy on reproduction therefore leading to increased fitness in the spiders. The evolutionary method of camouflage greatly increases the survivability and fitness of crab spiders. Another evolutionary strategy used by crab spiders is the selection for patches, which increases their fitness and survivability. According to Fritz and Douglass “selection for high quality patches in which to forage by M. vatia should contribute to greater reproductive success because of greater prey availability and therefore greater growth rate”(1985). They conducted a study on 10 spiders in which 6 spiders selected high quality umbels, 2 selected the lower quality umbels, and the other 2 selected both. They measured the weights of the spiders at reproduction and the spiders that selected high quality umbels weighed significantly more than the spiders who selected the lower quality umbels(Fritz and Morse 1985 ). The study concludes the selection of patches affects the weight of the females which in turn effects the reproductive success. The same conclusion can also be seen in a study done by Peter Kevan and Carlos Greco, in which they also tested the crab spider Misumena vatia showing the selection for high patches resulted in higher reproductive success. The studies conducted on Misumena vatia shows the selection for patches with high quality umbels increases fitness. Therefore selection for patches contributes to a greater fitness in crab spiders. The study of cues is also important in the selection of patches. Douglass Morse studied “insect prey presence, abundances, and distance in the selection of hunting sights” by the Misumena vatia to see if these cues had an effect of the selection of patches. In this study he measures the cues from 1983-1985 with varying variables. For example, he conducted an experiment on three umbels with high quality patches, middle quality patches, and low quality patches to see if the Misumena vatia had a preference. In this experiment, the Misumena vatia moved to different umbels with higher prey abundance within 2 to 3 minutes (Morse 1988). The study showed the Misumena vatia had a preference to higher prey abundance. He also conducted an experiment to test if the spiders selected for hunting sites. The study of the cues concluded the Misumena vatia had a preference for higher prey abundance and selected higher quality patches. The cues studied by Morse shows the importance of cues in the selection of patches. Thus showing the traits to select for the evolution of patch selection in Misumena vatia. The last evolutionary strategy used by crab spiders is a mixture of sexual selection and natural selection. Crab spiders displays sexual dimorphism meaning the female is bigger in size compared to the male spider. These sexual dimorphism are the result from natural selection and sexual selection. The male crab spiders that are fast at finding a female crab spiders have a reproductive advantage because the male will be able to pass on his genes. In this case the smaller the male crab spider the easier it is to move and search for females compared to being the same size as females. Thus the traits could select for the evolution of smaller male crab spiders(Morse 2007). Sexual dimorphism also has naturally selected for larger females because the larger the female crab spiders the better the reproductive success which means better fitness. Thus theses traits select for the evolution of larger females (Head 1995). The mixture sexual selection and natural selection has lead to increased fitness and survivability in crab spiders. In conclusion, the evolutionary strategies such as camouflage, selection for patches, and sexual selection all lead to higher survivability and fitness in crab spiders. Camouflage in the Misumena vatia and Thomisus spectabilis have lead to increased encounters of prey, therefore leading to better growth of females and increased reproductive success. The selection for higher quality patches allows for better fitness. The evaluation of cues also helps to select for higher quality patches. The sexual dimorphism and larger female size has lead to better fitness. The studies conducted by Morse, Fritz, Gabritschevsky, Gawryszewski, Greco and Kevan, Head, and other scientists can help with evaluating life histories of other organisms, the evolution of other organisms, and how to analyze and conduct significant experiments. Camouflage, selection for patches, and sexual selection are evolutionary strategies which has helped the survivability and fitness in crab spiders.

References Bradley, Richard A., and Steve Buchanan. Common Spiders of North America. Berkeley: 	University of California Press, 2012. Coddington, J..“Systematics And Evolution Of Spiders (Araneae)." Annual Review of Ecology 	and Systematics 22, no. 1 (1991): 565-592. Fritz, Robert S., and Douglass H. Morse. "Reproductive success and foraging of the crab 	spider Misumena vatia."Oecologia 65, no. 2 (1985): 194-200. Gabritschevsky, E. 1927. “Experiments on color change and regeneration in the crab spider 	Misumena vatia.” Journal of Experimental Zoology 47(2): 251-267. Gawryszewski, F. M., A. L. Llandres, and M. E. Herberstein. "Relationship between 	colouration and body condition in a crab spider that lures pollinators." Journal of 	Experimental Biology 215, no. 7 (2012): 1128-1136. Gray, Mike. "Spider origins - Australian Museum." Spider origins - Australian Museum. 	http://australianmuseum.net.au/Spider-origins (accessed October 28, 2014). Greco, Carlos F., and Peter G. Kevan. "Contrasting patch choosing by anthophilous ambush 	predators: vegetation and floral cues for decisions by a crab spider (Misumena vatia) 	and males and females of an ambush bug (Phymata americana)." Canadian Journal 	of Zoology 72, no. 9 (1994): 1583-1588. Head, Graham. "Selection on Fecundity and Variation in the Degree of Sexual Size 	Dimorphism Among Spider Species (Class Araneae)." Evolution 49, no. 4 (1995): 776. Morse, Douglass H.. "Cues Associated With Patch-Choice Decisions By Foraging Crab 	Spiders 	Misumena Vatia." Behaviour 107, no. 3 (1988): 297-312. Morse, Douglass H.. Predator upon a flower: life history and fitness in a crab spider. Cambridge, Mass.: Harvard University Press, 2007.

Edits to Wiki Pages

https://en.wikipedia.org/wiki/Misumena_vatia For example, in Misumena vatia's method of camouflage, it is able to focus its energy on growing and reproduction because it does not need to spend energy on finding food like other species of spiders. Crab spiders wait for their prey and lures in their prey allowing the female crab spiders to focus on growing and reproduction. Also by matching its environment, it does not need to focus on escaping from predators. In a study done by Robert Fritz and Douglass Morse, 163 adult crab spiders were measured over 3 years looking at reproductive success of the Misumena vatia. They concluded there was a positive correlation between female weight of the adult Misumena vatia and egg clutch size. [2]The conclusion means the greater the female weighed the more eggs were produced. Thus selection for larger female body size increases reproductive success. [3] According to the studies, Misumena vatia are able to focus its energy on growing and reproduction because of how effective the camouflage conceals the spider from predators. The effectiveness of the camouflage allows the spiders to also not spend energy on finding food. Due to the method of camouflage in Misumena vatia, it has helped increase its survivability and fitness.

https://en.wikipedia.org/wiki/Thomisus For example in the Thomisus spectabilis species, the method of camouflage is similar to the Misumena vatia except the Thomisus spectabilis blend in with their environment while being visible to their prey, but not their predators. This species of crab spiders are UV reflective while the flower is UV absorbing creating a contrast between the spider and flower through the eyes of the pollinator.[4] The contrast created greatly attracts pollinators such as honeybees. This evolutionary method of camouflage increased the likelihood the crab spiders encountered prey, which in turn effects the fitness of the crab spiders. Due to the increased encounter rate of prey the spiders are able to focus energy on reproduction therefore leading to increased fitness in the spiders. The evolutionary method of camouflage greatly increases the survivability and fitness of crab spiders.