A Tale of Two Slugs (Hannah, Camilla)

Earnest and Mildred: A Tale of Two Slugs

 

What it means to be a slug

Hannah Lin and Camilla Fimbres

April 29, 2015

Biological Semiotics with Andrew Yang

In Biological Semiotics we have learned the ways in which animals interact and communicate. We learned how they live keeping in mind the way humans live in the world. With a survey into topics of animal behavior (umwelten, natural selection and sexual selection, learning, instinct and engineering) we were able to thoroughly research the world of a slug. We are aware that we can not know exactly what it is like, but processing the information enough in order to think critically about the differences and similarities between humans and slugs. By way of a storybook called, Earnest and Mildred we developed a narrative about two slugs that find one another through their umwelt. They encounter many obstacles and everyday meanderings, but essentially through the eyes of a human it’s a story of love and loss. 

In our research we watched many scientific and artistic ways people see and understand slugs. We encounter land slugs in our everyday humid or crisp environments if we look close enough under us. Exploring in depth, we were able to watch sea slugs and banana slugs in their natural environments of water and forest. Some videos were sped up opposed to their slow demeanors, leopard slugs crowded around eating large mushroom stalks, pet slugs being petted, even a man who eats a banana slug, mucus and all, at the Redwood forest. There were many videos of slugs copulating in a way that seems sentimental and humanistic, which was what drew us to researching the species. We were drawn by their anatomy and our mixed feelings, how they can initially look appalling yet we can accept them as a personality, “cuteness.” 

We decided to make an adult type children’s book because the information for our audience could be easily processed and understood in this format. We looked up books on slugs, many children’s books were found, but handfuls were not close to the way slugs actually, truly live and socialize. Our goal in the time constraints and unlimited information is to research thoroughly enough to grasp onto what it means to be a slug. 

With the context of a storybook we will present the information we obtained and the visuals we worked on with a story time circle. We will hopefully have our circle read a paragraph each with vigor and energy that will bring life into the narrative of Earnest and Mildred. Scientific research and experiments were limitless. One that was interesting was Pearce, T.A. (1990) who came up with a technique for tracing field movements of terrestrial snails. He used a spool and line technique to trace the field movements of land snails. The spool is attached to a snail large and strong enough to carry it; the free end of the thread is tied to a landmark. The thread unwinds as the snail crawls around so that a record of the movement pattern is preserved. Another study took place between Gary F. McCracken and Robert K. Selander. They studied the genetic variation in 14 species of slugs in the eastern United States indicating that self-fertilization is the normal breeding system in six of the studies species. The findings have implications for theoretical work on evolution of breeding systems and the problem of relationships between environmental heterogeneity and the quantity and organization of genetic diversity in populations. This shedding of light on matings impact on evolution was fascinating next to our research of leopard slug copulation. 

We also explored how slugs can influence artistic endeavors in science and architecture. At MIT, professor Annette “Peko” Hosoi and her colleagues in the Mechanical Engineering Department: Brian Chan, Susan Ji and Catherine Koveal made models, RoboSnails I and II. Each of the robots was made up of electronics abroad a rubber foot and approximately six inches long by one inch wide. The robot is able to glide over a thin film of silicon oil imitating mucus. They were tested to mathematically simulate forms of snail locomotion, giving insight into biological systems (blood flow through a vein.) The Southern California Institute of Architecture students Astri A. Bang, Maya Alam, and Janni S. Pedersen with help by Ilaria Mazzoleni and Shauna Price designed architecture inspired by slugs. They made a banana slug like greenhouse with silicone prototypes of bladders that would encase the building and release water--like the slug that secretes mucus and has permeable skin. The findings helped bring context into how slugs contribute to a bigger picture of society. 

Ideally, once this project has come to fruition and presented, the aftermath would include a larger version of the book including complex humanistic narrative of the story of Mildred and Earnest intertwined with first hand research. Funding would help with materials, editions and printing of the book, as well as, opportunities for publications. A larger team and traveling would be beneficial to the overall project that would ultimately be recorded for a larger public and museum archive.

        

Annotated Bibliography

Crampton, Linda. "Slugs - Interesting Facts, Mucus Slime and Pest Control." HubPages. HubPages, 9 Sept.

2014. Web. 26 Apr. 2015.

Linda Crampton breaks down information of slugs in simple terms by the body, lives, nreproduction, slug slime and It’s function, Banana slugs, slug robotics, and getting rid of slugs: pest control, unusual slugs, hand pickings, drowning and salting, creating barriers. Crampton sheds light on the overall importance of Slugs. The HubPages is a website used as a platform for exposure and a resource that welcomes freelance passionate writers, that write on their own accord. The author uses videos and images to go along with the writing.

Crew, Bec. "Australian Sea Slug Sex in All Its Head-Stabbing Glory." Scientific American Global RSS. Scientific American, 13 Nov. 2013. Web. 26 Apr. 2015.

Bec Crew informs the reader on traumatic insemination between Australian sea slugs. He

sources the scientific research of the species from Roland Lange from the University of

Tuebingen in Germany, along with Johanna Werminghausen of Monash University in

Melbourne and Nils Anthes of the University of Queensland. The article questions sperm

injection site and the resulting hypothesis behind the questions. The article shows by way

of video of Siphopteron species in action of injecting fluid and storing sperm.

Edwards, Lin. "First Evidence of Sleep in Snails." First Evidence of Sleep in Snails. Phys.org, 8 Feb. 2011. Web. 26 Apr. 2015.

This is a short article into the sleeping behavior of a slug. With two experiments by

Associate Professor Richard Stephenson and Dr Vern Lewis of the University of Toronto,

they found information by the study of pond snails. The experiments result in evidence of

gastropod sleep we come to understanding of what defines sleep opposed to resting. The

information also benefitted in research pertaining to human sleep and our biological

processes and cellular functions in sleep. The article pulls from the Journal of Experimental

Biology publication.

"From the Mouths of Molluscs -- Ancient Snail Relative Found." From the Mouths of Molluscs -- Ancient Snail Relative Found. Phys.org, 22 Apr. 2012. Web. 26 Apr. 2015.

An unknown author pulls from a journal, Proceedings of the Royal Society B that offers a

comprehensive analysis of the origins of mouthparts of slugs. Martin Smith of University

of Toronto, Department of Evolutionary Biology, using new microscope technology to

study the ancient slug. Smith used an electron microscope. Molluscs are important because they are the second biggest animal group, but little information is accountable about their early evolution. This article is beneficial for a short synopsis of evolutionary lineage of traits that includes images and a link to a more in depth journal from Royal Society B.

Gervais, Jennifer A., Anna Traveset, and Mary F. Willson. "The Potential for Seed

Dispersal by the Banana Slug (Ariolimax Columbianus)." JSTOR. JSTOR, July

1998. Web. 26 Apr. 2015.

This is a study on wild banana slugs observed and recorded for research. The hypothesis that is tested is that slugs may act as seed dispersers. The information came to be as seeing slime trails showing that slugs are capable of reaching the fruits of wild plants. The scientists feed a number of captive slugs various fruit types to determine the effects of slug ingestion with seed germination. Only some seeds ended up germinating after fruit was consumed and the fruit that most likely germinated were recorded, fruit color also tended to morph over time. The results could not be tested statistically, but general habits suggest many complexities and ecological significant eggects of seed dispersal of Pacific Northwest forests.

Hickey, Ciaran. "Knowing the Lifecycle of a Slug Could Make the Difference to 2013's Harvest." Independent.ie. Independent.ie, 22 Aug. 2012. Web. 26 Apr. 2015.

This article shed light on slug’s behavior in order to better keep crop from damaging crop.

Information includes the areas of fields slugs inhabit, the seasons they most prosper and the weather that is most difficult. Their locomotion is briefly mentioned. The most information offered is on their reproduction behavior. Depending on species female slugs lay eggs between several days and weeks after mating and incubation is important. The weather along with reproduction is important to their abundance and the abundance of vegetation. They mostly reside in abundant vegetation because they do not move more than 50cm per day according to the author, Ciaran Hickey.  

"How Sea Slugs Fall in Love." How Sea Slugs Fall in Love. Phys.org, 14 Apr. 2007. Web. 26 Apr. 2015.

This article, with an unknown author, briefly talks about a discovery in 2007 by Scott Cummins and his colleagues at The University of Queensland. A mix of chemicals was found to be potent and act as pheromone that can help stimulate the affection of mate for a sea slug. This discovery can function as research to develop tools to eliminate pest species and enhance management of similar animals in aquaculture according to Cummins. This discovery has already instigated more research for other marine animals that may have pheromone messages to uncode. The article is based on work that is published in Proceedings of the National Academy of Sciences USA and The Journal of Biological Chemistry.

Penn State. "Insecticides Foster 'toxic' Slugs, Reduce Crop Yields." Insecticides Foster 'toxic' Slugs, Reduce Crop Yields. Phys.org, 4 Dec. 2014. Web. 26 Apr. 2015.

This site specializes in hard science subjects. This research has been published in other news sources, but provided by Pennsylvania State University in the Journal of Applied Ecology. The information suggests that insecticides that control early season crop pests increase slug population, which reduces crop yields. John Tooker of Penn State is an associate professor of entomology. According to Tooker and Margaret Douglas, graduate student, Neonicotinoids can worsen pest problems. In an experiment researchers concluded by submitting samples of field experimentation to analytical laboratory that slugs are unaffected and transmit the neonicotinoid to ground beetles. 

Mccracken, G. F. "Self-Fertilization and Monogenic Strains in Natural Populations of Terrestrial Slugs." Proceedings of the National Academy of Sciences 77.1 (1980): 684-88. JSTOR. Web. 08 Apr. 2015.

Gary McCracken and Robert Selander study the genetic variation in 14 species of terrestrialslugs of eastern United States. They study the breeding systems where in six of the species self fertilize. Eight of the species are outcrossers. The niches asses the extent of geographic distribution and the variety of habitats occupy and measure on an experimental plot of woodland. They found that colonizing success is independent of the genetic variations. The report is useful with regard to breeding systems, genetic structure of populations and patterns of speciation. They note that their findings are helpful for theoretical work on evolution of breeding systems and the fundamental problem of the relationships between environmental heterogeneity and the quantity and organization of genetic diversity in populations.

McKinley, Gareth. "Gareth McKinley's Non-Newtonian Fluid Dynamics Research Group at MIT." Gareth McKinley's Non-Newtonian Fluid Dynamics Research Group. MIT, 18 Nov. 2013. Web. 26 Apr. 2015.

This site is a useful resource run by the Department of Mechanical Engineering at MIT.

Their research is very broad and dense including in depth experiments and observations

broken down into equations, synopsis, videos and images. The research includes slug

mucus. An introduction to the properties of mucus are defined as well as a definition. A

video experimental setup by Randy Ewoldt is available for download, a link to his website

and his study on mucus by particle image velocimetry. You can see the waves in the mucus

whole the snail moves by Brian Chan for a greater visual understanding.

Miller, Brooke Luana Weaver. "Home of the Slug Love." Home of the Slug Love. University of California, Santa Cruz, 1 June 2004. Web. 26 Apr. 2015.

This site was set up by an author that studies evolutionary biology with an interest in

banana slugs. She is interested in these organisms because of the sexual conflict they

experience between hermaphroditic mating partners. In an organized manner the author

asks questions, such as, what is sexual conflict? What happens when there is sexual

conflict? Why study banana slugs? What is interesting about banana slugs? Does the slug

penis grow back? She answers these questions and attaches download links to videos of

banana slugs attempting to mate. One slug was unable to retract its penis. After a few

hours, a slug slurps down its own penis.

Rathcke, Beverly. "Slugs as Generalist Herbivores: Tests of Three Hypotheses on Plant Choices." JSTOR. JSTOR, June 1985. Web. 26 Apr. 2015.

Beverly Rathcke work at the Department of Ecology and Systematics at Cornell University.

In the journal she tests three hypotheses explaining plant choices by generalist herbivores

tested by measuring leaf acceptability to three slug species, each living in different stages

of vegetation, 61 plant species were determined in feeding trials. Field observations also

suggested that slug species exert selective pressure on the morphologies, phonologies and defenses of native plants.

Sakai, Jill. "Eavesdropping Plants Prepare to Be Attacked." Eavesdropping Plants Prepare to Be Attacked. Wisc.edu, 5 Apr. 2013. Web. 26 Apr. 2015.

Jill Sakai writes on the studies of John Orrock and Simon Gilroy of the University of

Wisconsin-Madison. According to the studies, seeds exposed to herbivore kairomones

becomes seedlings that are less palatable to them. They do this by boosting their toxic

production or building physical defenses. The chemicals are like cyanide, sulfurous or

acids, while physical attributes develop like thorns or tougher leaves. Gilroy, a botany

professor reported in 2013 the defensive responses before any plant is attacked. Orrock

explores the genetics and evolution of the induced defenses. He also studies snail slime as a

defensive mucus.

Smolensky, Nicole, Melissa R. Romero, and Patrick J. Krug. "Evidence for Costs of Mating and Self-Fertilization in a Simultaneous Hermaphrodite With Hypodermic Insemination, the Opisthobranch Alderia Willowi." The Biological Bulletin. Biol. Bull, Apr. 2009. Web. 26 Apr. 2015.

This publication is by researchers of the Department of Biological Sciences, California State University of Los Angeles. They study the coevolution between sexes that function as both male and female. They studied sea slugs, Alderia willowi, that initially laid unfertilized eggs but 4 days later began self fertilizing when isolated. Egg production increased for wild slugs separated after mating compared to slugs held in pairs. This indicated that accessibility to mates imposes a fitness cost to the female function. In the male role they carry a competitive advantage but diminish reproduction as female among hermaphrodites capable of long term sperm storage. The studies show that slugs switched between development modes at some point where in reproductive flexibility within individuals is not known before.

United States. National Park Service. "Banana Slug & Millipede." National Parks Service. U.S. Department of the Interior, 26 Apr. 2015. Web. 26 Apr. 2015.

The National Park Service offers distinct information of banana slugs that inhabit the

Red wood forest in Redwood National and State Parks. They talk about spineless creatures

including the yellow spotted millipede. The species are unrelated, but are widely seen on

trails of the forest. They are most prevalent in coastal rainforest from southeast Alaska to

central California. Both are decomposers. They consume detritus of decomposing plant and animal parts. They are very important to the nutrient cycling of the forest ecosystem. Other benefits include, seed dispersal and are preyed on by raccoons, garter snakes, waterfowl and salamanders.