SnailsloveSean


 * Snails Past Present and Future**
 * By Sean O'Reilly Year 10 Science Ms Voss's Class 2011**

Welcome all, Especially generous marking science teachers, But not the French! This is my wiki page on the evolution of snails Time to break the Ice: What is a slug? A snail who can't pay rent!



Lets face it snails have been around for a goddamn, but lets get a blast from the past and stroll down (very slowly in the snail's case) memory lane and look at the snail in the past. The snail in question is the **sinistrofulgur lebelleensis** (closely related to Sinistrombus both part of the Strombidae family Class: Gastropodus Phylum: Mollusca) more information can be found here **1.**(**[]**) **2.**(more information on the strombidae family[|http://en.wikipedia.org/wiki/Strombidae)which] was a prehistoric sea snail that lived in and around Florida during the early Pleistocene Period which was 1.5 to 1.8 million years ago. But mainly in the Gulf of Mexico, Closlely related to **3.**( ** //Sinistrofulgur grabaui// ** //which can be found here// http://www.paleodirect.com/ga-004.htm)
 * Extinct Snail**
 * Environment**
 * Fun Fact:** The Gulf of Mexico spans 2700 km of US coastline and is almost landlocked with the exception of an opening near the island of Cuba. The aspects of this environment include:
 * 1**.Warm waters which allowed for the snail to live there comfortably without having to relocate in winter which would be extremely difficult form a snail however this species was quite big as a preserved shell that was found was 11 inches in length and could move against tidal currents. However serious relocation to avoid cold winter weathers would be impossible due to the size of the gulf.
 * 2.** Another important aspect is that the Gulf of Mexico is a drainage basin for almost 33 rivers in the US and is extremely rich in nutrients and shrimps and bivalves which provided the snail with an abundant food source and little need to travel far to find the food it needed.
 * 3.** The Gulf of Mexico is almost landlocked except for an opening near Cuba, this relative isolation has allowed for very little disruption of food source or very little predators that could prey on the snail or it's food however in certain parts of the year a strong Atlantic current enters the Gulf and is one of the worlds most powerful current, this is a disruption that will be highlighted later on.
 * 4.** The final aspect of the Gulf of Mexico is a large continental shelf that can range form 40km in width to 320km this huge shelf provides an area for sediment to be deposited and where marine animals live that the snail can prey on as the continental shelf contains everything from mangroves to open water. In particular bivalve molluscs especially oysters which are the favourite food of this snail.



It's time for some adaptations and why they adapted!
 * Adaptations**
 * 1**. This snail was quite large in size for a snail, the length of it's shell (pictured below) is 11 inches and with a height of approximately 22 inches this was a big snail, we can infer from the sheer size of this snail that being preyed upon was no real issue, however this size is probably an adaptation due to increased predation by larger organisms.Then after a while the snail grew in size so that it would no longer have to worry about being preyed upon because of the size of it in comparison to other snails. This helped it intimidate others into not eating **it. Pressure**: As was mentioned before the pressure that caused this snail was probably an increase of predation by larger organisms then itself, and that tidal currents in the gulf are extremely strong and a snail under that size would have trouble escaping it's grasp. **How it helped it's survival.**The size of this snail helped it to seem bigger in comparison to other snails so that it would not be a suitable choice of prey for any predator because of it's size and the appearance of toughness that this brings. However it would have to watch out for stingrays that roam the sea floor **4.**(Bowen Lim's Wikihttp://designeranimals2011.wikispaces.com/Stingray)


 * 2.** A quite unique adaptation was a foot that the snail possessed, a snail possessing a singular foot is certainly not uncommon but the foot on the underside of the snail was quite large and powerful. This meant that the snail was able to traverse large distances to find food and could travel against a strong tidal current due to it's mass and extremely strong foot. **Pressure**: An environmental factor that could have given rise to this adaptation is the extremely strong tidal currents produced by the Gulf of Mexico these currents would probably drag a lesser snail to it's doom therefore the snails adapted to have a powerful foot that could hold it's own against tidal currents. **How it helped it's survival:** This powerful foot meant that it would not be able to be dragged put by powerful tidal currents allowing to venture further for food and not be caught off guard.


 * 3.** Another adaptation is to do with the foot, except the foot in this case has become a useful feeding appendage, when the snail hunts for food (mainly bivalves) it uses it's foot to attach to it's prey then it would slowly rasp a hole in the shell of it's prey and then feed off the juices and meat inside. That is why the majority of it's prey consist of bivalves, because it has the adaptation that allows it to bypass the shells defence and feed on the mollusc. **Pressure**: The reason that it had adapted this way was to feed off the easiest food source, simply because it couldn't eat fish and plankton is too small to satisfy it, it had to feed on bivalves. Although bivalves don't move which make them and easy target, they have a shell to protect them and thus foot feeding was born. **How it helped it's survival:** This meant that it could exploit the easiest available food source.


 * 4.** An adaptation that is especially unique to this snail (to the sub genus sinistrofulgur) is large protruding spikes that are on the shell. Not only do these serve as a funky shell accessory but they also allow two things. They allow the snail to seem more formidable aesthetically because protruding spikes are pretty bad-ass and also they serve as protection from any organism foolish enough to come close and try and attack it. **Pressure**: The main reason this adaptation occurred is the increased predation of this snail species and combined with the size that it had grown and the protruding spikes, this snail was formidably defended aesthetically and physically. **How it helped it's survival:** These spikes meant that anything who decided to charge into it would find a nasty surprise and that it would also deter predators.


 * 5.** The final adaptation is a behavioral adaptation which is how the snail hunts. It often hunts alone and on the floor of the coastal shelf looking for bivalve to eat. The reason that they hunt alone is probably due to competition from other snails especially since the process of eating a bivalve takes a while to complete. This type of snail was quite a loner and didn't always travel together except for finding a mate. **How it helped it's survival:** This lone wolf mentality meant that it would not need to fight for food.


 * 6.** Another adaptation is the powerful foot is used for jumping across the floor, this is a characteristic of the strombidae family. **Pressure**: The need for this was probably to allow for faster access to food and greater ability to escape if the need arisen. **How it helped it's survival:** This would allow it to track and reach food faster and it would allow for greater and faster unimpeded movement and the ability to escape from large tidal currents or a predator.


 * Here is an artists rendering of what sinistrofulgur lebelleensis would look like:**




 * Annotations**: **1.**Long Spikes protruding from the shell allow for extra protection, **2.**Powerful foot to propel it along the sea floor, **3.**Long eye stalks are the staple of the strombidae family, **4.**the size of this snail was 11 by 22 inches which made it one hell of a snail,**5.** there is only one snail in this picture because they hunt alone **6.** the foot on the bottom was also used for eating because it was able to penetrate the shell of bivalves by rasping them. (Some of the annotations didn't show)


 * Why did they go extinct**: There are many factors that can contribute to the extinction of a species, for example shortage of food or increased predation. However due to the size of the snail and it's defence mechanisms we can infer that it didn't got extinct because of increased predation. However in recent years very few of the fossils have been found, so we can infer that it is quite a rare species. Shortage of food is quite unlikely because the Gulf of Mexico is rich in minerals and bivalve molluscs for the snail to feed upon so a shortage of food is probably not the reason for it's extinction.As previously this species is quite rare and from that we can infer that their numbers were few and scattered after the Pleistocene era so the mos plausible explanation for it's extinction is the lack of breeding partners and shortage of numbers which lead to small and scattered population and then extinction.



Well! Wasn't that a blast from the past, now we will look at the snails now and how they are faring in today's modern society. The snail we will look at now is the Giant African snail (//**Achatina achatina**//) which inhabits the west side of Africa namely: Sierra Leone, Benin, Ivory Coast, Togo, Ghana and Nigeria. It is one of the biggest snails on Earth and can reach sizes of 18 centimeters and can weigh up 1 kilogram. However this shouldn't be confused with the East African land Snail which is a close cousin **1.**([]) The Giant African Snail inhabits the west side of Africa as was mentioned before, this is quite a large area which spans 6 countries and is in excess of 6,000,000 km squared. There are many aspects of the environment that the snail lives in but here we will zone in on the Ivory Coast. The Ivory Coast is a country on the West of Africa, it has a area of 300,000 square km, borders Liberia and Mali and has a population of 20,000,000. Ivory Coast is also home to types of baboon who live in forested and savanah areas **2.**(http://designeranimals2011.wikispaces.com/Baboon)
 * Modern Snails**
 * Kingdom || Animalia ||
 * Phylum || Mollusca ||
 * Class || Gastropoda ||
 * Order || Heterobranchia ||
 * Family || Achatinidae ||
 * Genus || Achatina ||
 * Species || A.achatina ||
 * Environment**
 * Aspects of this environment include:**
 * 1.** The Ivory coast posses a warm and humid climate in the middle and South and an Equatorial to Tropical climate in the North. There is a warm and dry season which ranges from November to March, then hot and dry from March to May and hot and wet from June to October. The temperatures range from 10-40 degrees Celsius at their extremes. This environment is specially suited to snails because it is not so hot that the snails will die and it is not cold but has a good level of Humidity. This allows the Snail to live comfortably, another reason is because the Ivory Coast has excellent forest coverage which makes a perfect habitat for the snail. That is because the forest is full of tasty leaves for the snail to eat and lots of coverage if the snail needed to hide. This creates the perfect temperature balance for the snail to inhabit, the region which they inhabit is usually the middle of the Ivory Coast.
 * 2.** The Ivory Coast is known for it's extensive forested areas that use to cover up to 60% of the country, these was essential for the survival of the snail as it needed the coverage from the leaves to keep out the heat of the day and of the hot season but also forests provide an abundance of food such as leaves and other shrubs and plants for the snail to feed on. It also provides a place for it to live as snails can rest and sleep in the shade of the trees during the afternoon heat. Forests can also provide shelter for snails in monsoon season where dangerous and infrequent torrential flooding is often frequent.
 * 3.** Rain forests have an extensive forest floor, that is often filled with a variety of: small shrubs, insects, leaves that fall from other trees, the trunks of big trees and old logs. All these things contribute to the snails existence. Many leaves that fall down from tall trees allow for an easy meal for the snail and logs can provide shelter for a snail in case of sudden rains or a beating unforgiving sun. Insects allow for all the dead leaves to be disposed of and fertilizes the ground for other plants to grow. Finally small shrubs allow the snail to feed off them which provide the snail with nutrients it needs to and thrive. Fruit that falls to the ground is also an easy meal fort the snail and that is another important aspect of the rain forests in which it lives, the forest floor.
 * 4.** Rain forests also contain many different types of animals that exist in harmony which makes it one of the most diverse biomes on Earth, this includes a staggering amount of animal variety which help each other in many different ways that allow the snail to survive and thrive. For example the feces of many animals fertilize the soil and allow for extensive shrub growth on the forest floor. Insects also help by assisting in the decomposition of fruit and organic matter which aids the snail in it's consumption. This provides the snail with an abundant food source as mentioned before and it means that the snail can live in relative comfort as it has no fear of predation by others and their food source is maintained by a carefully balanced biome.






 * Adaptations:**
 * 1.** This adaptation is quite similar to sinistrofulgur lebelleensis, the adaptation is the large size of the snail which can range from 18-20 cm in length and up to and including 9 cm in width. This would make them one of the largest snails and certainly on of the heaviest weighing in at 1 kilogram. This frankly massive means that it will have little if any competition for food sources and that it would make it seem physically more impressive because of the sheer size of this snail. This access to food and lack of prey meant that the Giant African Snail can live in relative peace because no animal would want to go near it. However it is an important source of protein for the indigenous people. **Pressure:** The reason it evolved into a monster of a snail is probably because of increased predation by other animals and a bigger size would make it seem more formidable thus leading to a decrease in predation.


 * 2.** An adaptation that comes for any snail is it's trademark, it's shell. This shell is with them when they mature and it grows with them. As snails get older their shells coil more and more the process of a snails shell coiling is called torsion. The shell helps it to survive by becoming a valuable source of protection from any predator. This is because the shell is quite big which allows for increased protection of the softer bits of it's body from attack, especially attacks from above. Like the Scissor Tailed Kite **3.**([]) And all the snails organs are actually housed inside the shell which make it an even more vital piece of armor. **Pressure**: The reason this adaptation may have arisen is probably increased predation from birds that is why the shell grows on top of the snail and that is why it is quite large.


 * 3.** The third adaptation is that all snails are hermaphroditic which means that they can be both sexes at the same time, this is also because they have a penis and a vagina right next to each other. This is an extremely useful adaptation for a number of reasons: Firstly if there was a shortage of breeding partners then the snail could change gender to accommodate another snail before the sexy time. Another reason is that they can give birth sooner because of this but that kind of ties into the previous reason because they can just become impregnated by another snail then lay it's eggs. **Pressure:** The reason that probably gave a rise to this adaptation was a shortage of breeding partners and that is why they had to become hermaphroditic to survive but now their numbers are increasing.


 * 4.** The fourth adaptation is the frequency at which snails lay their eggs. Snails can lay up to 200 eggs in one sitting and 1200 a year, these eggs take only 2 days-7 weeks to be laid and hatched. This coupled with their size makes them a potential pest for farmers however their numbers have been shortened by a bacterium which I will mention later. The reason his helps it to survive is because this can increase the population in desperate times, this can allow for higher survival rate of potential offspring, and because of the frequency of birth this allows for more genetic modifications to take place in a shorter amount of time and that will help the species adapt to the environment even quicker. **Pressure:** The reason for this probably the same as the one outlined above, basically it allows for greater population growth and for the speed of genetic modification to increase.


 * 5.** The final adaptation was a resistance to a bacteria related to Aeromonas liquefacians which was shortening their numbers significantly. This allowed them to no longer succumb to the bacteria however a more pure strain of Aeromonas liquefacians has appeared and is shortening the numbers once more but an immunity to this new type of bacteria has not been achieved yet. **Pressure:** The reason their immune system adapted this way was to combat the bacteria that killing them off, for a while the snails were immune but then a purer strain appeared and is killing them off once more.
 * Feast your eyes on the Giant African Land Snail**



Now let us transport 1 million years into the future, where the world is ruled by corporations, Apple has released the Iphone 5 and where IM's are sent by thought alone! But who cares about that stuff, that's old news in the year 1,002,011 AD. Now the future prepares itself for the..... Let us take a look at the world of the future and the environment that the **Giant African Snail 2.0** inhabits, the Ivory Coast has changed from what we know now, it has been part of 15 civil wars, massive deforestation and desertification however Earth's overmind has tried to bring back the lush rainforests of days gone by, progress is slow and the **Giant African Snail 2.0** lives in a very different world. And has become more of a ramshorn snail **1.**(http://www.fishpondinfo.com/snail2.htm#four) rest of the year the climate becomes more humid and wet and the formerly harsh scrub land becomes wetland for the rest of the year before the dry season starts again. Temperatures now range from 20 degrees Celsius to 46 degrees Celsius and the former Comoe river (See map of Ivory Coast) has dried up and become desert and the Sassanda swells up every wet season.
 * Future Snail**
 * Giant African Snail 2.0**
 * Environment**
 * 1.** The Ivory Coast now has become arid scrub land and harsh mountains however small pockets of forest remain, the climate is now mostly arid from October through June but for the
 * 2.** From the 60% of Ivorian Forest land, only 10% of it's former glory remains, leaving mainly isolated pockets of forest in hard to reach areas and on the fringes of near deserts. Now the snail has become adapted to newer drier conditions in the near arid scrub land, where the ground is dusty and shrubs prickly. Now the rain forests of old are home to a select few snail who were unaffected by the Ivorian Wood Crisis of 989,999,999 AD where the demand for Ivorian trees went through the roof and deforestation was rampant. Now Rain Forests are a dreamy memory to the next generation of snails.
 * 3.** Now that the forest floor has been replaced by arid scrub land the snails now reside in the many craters from the Ivorian wars. In these craters are now diverse number of lifeforms that thrive there when rainwater collects and when they are unexposed to the heat of the day. It has been reported that small shrubs and saplings are growing in the shade. Now the snails roam the extensive craters where the feast on small shrubs and the of carcasses of beetles which are a great source of calcium for the snail.
 * 4.** Although the craters of the scrub land cannot compare with the ridiculous diversity of rainforests animals in the craters provide a well balanced microcosm where all the animals interact well. For Example the beetles fertilize the soil because they are dung beetles which allows the snail to feed on not only the dung but the fertilized shrubs but when the beetles die the snail will feed on their carcasses to get their dose of calcium which is important for snails as it stimulates shell growth. E.g. The Dung Beetle **2.**([])
 * Adaptations**
 * 1.** Since The Ivory Coast has become quite arid the snail no longer produces slime due to moisture conservation reasons and now the snail's skin has become quite leathery and coarse to accommodate moisture conservation this allows the snail to conserve moisture but move around more and the leathery skin allows it to become more immune to sun drying. This allows it to survive longer in the sun which will allow it to be able to dart from crater to crater without the risk of being sun dried or losing moisture due to extreme exposure to the now harsh Ivorian sun. **Pressure**: The pressure that caused this adaptation is the harsh Ivorian sun and the desertification of once lush rainforest combined with the adverse effects of rampant global warming on the West African region.
 * 2.** Another adaptation is a smaller and more compact shell. This adaptation helps the snail by making it lighter which will assist in the aforementioned crater dashing and reducing the amount of the snail's surface area that is exposed to the sunlight. Another reason a compact shell is good is because it allows for a denser but not heavier shell which will still offer significant protection but it will not hinder the movement of the snail, especially in the short bursts when it dashes from crater to crater to avoid sunlight. **Pressure**: The reason this adaptation has occurred is because previous generations were too slow when dashing from crater to crater, they then experienced loss of moisture and usually died before reaching the other crater.
 * 3.** An interesting adaptation is the adding of small feelers to the bottom of the snail which replaces the big foot at the bottom which was usually quite moist and relied on slippy sliding along. However these new feelers allow the snail to dart quickly but in short bursts and the reduce the amount of surface area touching the ground which in turn reduces moisture loss when the snail darts from crater to crater. **Pressure:** The reason that this adaptation took place was because previous generations were expending too much moisture getting from crater and the muscular foot became dry and cracked like the earth the slithered on.
 * 4.** A behavioral adaptation is called crater dashing, it has been mentioned many times before and is the main way snail move between craters. They choose the crater they want to go towards and then they dart at it as fast as their feelers can carry them so that they do not get exposed to the harsh afternoon sun which could easily bake a snail a live and then the Ivorians would be eating escargot for lunch! **Pressure**: The reason they adapted this way is that they realized that a slow crawl in the general direction of safety wasn't gonna cut it. So after they evolved the feelers on their feet they were able to dash faster and more accurately to the safety.
 * 5.** The fifth and final adaptation is the complete opposite of sinistrofulgur lebelleensis, due to the exposure to sunlight the snail has shrunken in size to accommodate a smaller surface area that would be exposed to sunlight and so that it would be able to crater dash more effectively and quickly. This smaller size will also allow it to fit into smaller craters that would not usually be able to hold a **Giant African Snail 2.0** can now accommodate one with relative ease. The snail has shrunk from 18cm to 8cm and from 9 cm to 5 cm in length and width respectively. **Pressure:**The reason this adaptation has come about is because of the past generation's failings in the fact that previously they couldn't fit into craters that were quite small and that the area exposed to sunlight is quite large. It will also help it avoid predators **3.**([])

There is a big pressure for extinction when it comes to the snail in the future. The problem is that since the deforestation and desertification the scrub land is harsh and arid. Therefore cannot support much life, especially the small intricate biomes of the craters. These craters can range from a meter to 20 meters in diameter and are not big enough to support a large scale snail population. The reason I say this is because as was previously mentioned, snails reproduce rapidly and the only reason they have survived until now is that their numbers have been decimated by the deforestation. Now however the population is on the climb and that means that the small craters will not be able to support a snail population for much longer, this overpopulation and strain on resources is the most likely cause for future extinction.
 * Extinction Pressure**


 * Now for an artists rendering of the Giant African Snail 2.0**



1. Sinistrofulgur lebelleensis retrieved from http://www.paleodirect.com/pgset2/ga040.htm at Paleodirect.com on 18th of June 2011 2. Strombidae family retrieved from http://en.wikipedia.org/wiki/Strombidae at Wikipedia.org on the 18th of June 2011 3. True Conchs (Strombidae family) retrieved from http://shells.tricity.wsu.edu/ArcherdShellCollection/Gastropoda/Strombidae.html at shells.tricity on 18th of June 2011 4. Sea Snails retrieved from[]from Sea Snails on 18th of June 2011 1. Giant African Snail retrieved from http://en.wikipedia.org/wiki/Achatina_achatina at Achatina Achatina on the 20th of June 2011 2. Ivory Coast retrieved from http://en.wikipedia.org/wiki/C%C3%B4te_d%27Ivoire at Cote'd Ivoire on the 20th of June 2011 3. Tropical Rainforests retrieved from http://www.blueplanetbiomes.org/rainforest.htm at Tropical Rainforest on 21st of June 2011 4. Giant African Snail Size Sheet from http://www.massnrc.org/pests/pestfaqsheets/giantafricanlandsnail.html at Pest Protection on 22nd of June 2011 1. Ivorian Civil War retrieved from http://www.foxnews.com/world/2011/04/04/critics-blast-obama-neglecting-ivory-coast-civil-war/ at Fox News on 23rd of June 2011 2. Ivorian Deforestation retrieved from http://rainforests.mongabay.com/20cotedivoire.htm at Monga Bay on 23rd of June 2011 3. Tropical Rainforest Biome retrieved from http://www.globalchange.umich.edu/globalchange1/current/lectures/kling/rainforest/rainforest.html at The Tropical Rainforest on 23rd of June 2011
 * Bibliography**
 * Extinct Snail**
 * Modern Snail**
 * Future Snail**