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Newmansr. You can use it for testing or practicing edits. This is not the sandbox where you should draft your assigned article for a dashboard.wikiedu.org course. To find the right sandbox for your assignment, visit your Dashboard course page and follow the Sandbox Draft link for your assigned article in the My Articles section. |
References:
Relevance to the topic:
Distracting Information:
Neutrality:
Source Neutrality:
Viewpoint Representation:
Citation Link Function
Plagiarism and Close-Paraphrasing
Out-of-Date Information
Missing Information
New Text: Many domesticated bird species have crest feathers. These structures are known to have two origins: selective breeding or mutations. Crest feathers in domestic birds include a wide range of variations in form across species. The underlying molecular and genetic mechanisms that are responsible for crest feather formation in domesticated bird species are not well-understood. As such, crest feathers are widely studied in morphological research and other related biological disciplines, particularly concerning domesticated species. [1]
- I'm interested in dissecting the iguana because it is an animal that I do not know very much about and would like to explore in depth. I'm interested in dissecting the garter snake because they were a big part of my childhood, and also because I'm interested in exploring the anatomy of an animal with a secondary loss of some feature, such as the snake's loss of limbs.
- Possible page edits: Brumation Dormancy#Brumation, Tetrodotoxin Tetrodotoxin, Heterothermy Heterothermy
- I'm interested in dissecting the iguana because it is an animal that I do not know very much about and would like to explore in depth.
- Possible page edits: Iguana Iguana, Parietal Eye Parietal eye, Dewlap Dewlap, Tympanum Tympanum (anatomy)
- I'm interested in dissecting the frog because it's an organism that I have some experience with, but not with any precise instruction or dissection. I'm interested in learning more about the frog, and applying new knowledge to an organism I already have a base with.
Our group, the garter snake, has collectively decided that we should work together to add information about the Garter snake's anatomy to it's specific page. We will attempt to take our own photographs of the Garter Snake, and try to flesh out the page as much as we can with respect to anatomical topics. We will link to the Snake when applicable, and may draw from sources listed on the snake site.
Aside from just working on the garter snake's page itself, our group has decided to undertake individual pages that relate to the Integumentary system of the snake.
My Sandbox will serve as the group's sandbox page, and all of our collective work can be found here /info/en/?search=User:Newmansr/sandbox?veaction=edit§ion=4
Sara, me, will be independently responsible for researching and adding to information about the Skin of the snake ( Snakeskin). So far, the major information on Wikipedia about snake's skin is either fashion related, or has to deal almost exclusively with Snake scales. Very little is listed regarding the snakes actual soft integument. Other information that I will try to study about the snake's skin includes shedding of the skin, skin pigmentation, skin structure and function, and it's attachment to underlying muscle.
Ryan will be researching Duvernoy's gland independently. A lot of good sources are already listed on the page itself, but very little applicable information has been included on the page. He will be working to improve the page with it's existing references and new ones.
Huy will be researching Vomeronasal organ, also known as Jacobson's organ, and the sense organs of the garter snake. He hopes to be able to dissect out our garter snake's Jacobson's organ and include an actual photograph of the structure, and not just a drawing, on the page. He also wants to improve the information that is present on the page.
Group References:
- Bauchot, Roland. Snakes: A Natural History. New York: Sterling Pub., 1994. Print. [2]
- Mattison, Christopher. The Encyclopaedia of Snakes. London: Blandford, 1995. Print. [3]
- Mattison, Christopher. The New Encyclopedia of Snakes. Princeton: Princeton University Press, 2007. Print. [4]
- Parker, H.W. Snakes - A Natural History Talks. London: Cornell University Press, 1977. Print. [5]
- "Different effects of lesions of the vomeronasal and olfactory nerves of garter snake (Thamnophis sirtalis) responses to airborne chemical stimuli (PDF Download Available)" ResearchGate. Retrieved 2017-03-11. [6]
Garter Snake Talk Page Post:
This page already has some great content on it, but I've noticed that there isn't much on the anatomy of the garter snake itself. Myself and two of my classmates are proposing to add an anatomy section to this page with linking subjects that already exist on the snake page. We want to further add to content that already exists on the page if possible as we undergo this endeavor. We plan to include photographs of the anatomy of the garter snake that come from public domain, and have a list of some proposed sources for page content that we would like to use to cover some of the basics. Photographs would be generated by ourselves as we dissect a garter snake in class. Our initial proposed sources are as follows:
-Bauchot, Roland. Snakes: A Natural History. New York: Sterling Pub., 1994. Print. [2]
- Mattison, Christopher. The Encyclopaedia of Snakes. London: Blandford, 1995. Print. [3]
- Mattison, Christopher. The New Encyclopedia of Snakes. Princeton: Princeton University Press, 2007. Print. [4]
- Parker, H.W. Snakes - A Natural History Talks. London: Cornell University Press, 1977. Print. [5]
If you think these would be good sources to begin with, please let me know. If you can point us in the direction of other useful sources that you are aware of, or other additions that you think would benefit the page that are along these lines, that information would also be helpful. Any input you have on our endeavor for this project would be useful, thank you.
Snakeskin Talk Page Post:
This page has a lot of potential, and I'd like to proposed adding to it. So far, there are not many sources for this page, and I'd like to propose a few that may be useful:
-Filippov, Alexander E., and Stanislav N. Gorb. "Modelling of the Frictional Behaviour of the Snake Skin Covered by Anisotropic Surface Nanostructures." Nature News. Nature Publishing Group, 23 Mar. 2016. Web. 10 Mar. 2017. < http://www.nature.com/articles/srep23539>. [7]
-Bauchot, Roland. Snakes: A Natural History. New York: Sterling Pub., 1994. Print. [2]
- Mattison, Christopher. The Encyclopaedia of Snakes. London: Blandford, 1995. Print. [3]
- Mattison, Christopher. The New Encyclopedia of Snakes. Princeton: Princeton University Press, 2007. Print. [4]
- Parker, H.W. Snakes - A Natural History Talks. London: Cornell University Press, 1977. Print. [5]
With the help of these sources, I would like to add information about the soft integument of snake skin to this page, as there is limited information about this on Wikipedia at present. Most of the information that I could find about §snakeskin has been about §snake scale, rather, and I think exploring snake skin on its own is important. It has a vital function, and I think it deserves some attention. it is a critical piece of §snake anatomy and is not well addressed. Further, I would like to add information to this page about snake skin §pigmentation or coloration, which may link to §albinism or §melanin or other such §pigments that contribute to the color of snakes.
Please let me know if you think these sources are appropriate, or if you can think of other sources or content areas that might be worth addressing as I endeavor to improve this page.
Duvernoy's Gland Talk Page Post:
Considering using the current sources on this page to flesh out this article. Further sources may be used in the future as I find them/gain access to them. Kenneth Kardong, who wrote three of the current sources, has additional articles related to Duvernoy's gland which I am currently trying to access Murry4329 ( talk) 04:29, 11 March 2017 (UTC)
Vomeronasal Organ Talk Page Post:
The Wiki page of the structure has a great amount of information already. However, there is only one sentence about how snakes use the vomeronasal organ and it's not even cited. I'll look for sources to add to that and expand more on that section if possible. Since I'm going to dissect a garter snake, I'm planning to add an image of the organ from my project as well. Is that possible? The listed sources below can be used in my projects:
Bauchot, Roland (1994). Snakes A Natural History. Spain: Sterling Publishing. pp. 52–56. ISBN 0806906545. [2]
Mattison, Christopher (2007). The New Encyclopedia of Snakes. Princeton University Press. p. 44. ISBN 9780691132952. [4]
Parker, H. (1977). Snakes - A Natural History Talks. Cornell University Press. p. 28. ISBN 0801491649. [5]
Garter Snake:
In thinking about the anatomical information that we want to add to this page, we've begun to make a plan regarding what pieces of anatomy we want to include in depth. We will be focusing on Duvernoy's gland, which is responsible for venom production, the Vomeronasal Organ (also known as Jacobson's organ), which is responsible for sense of smell, and the skin of the Garter Snake (as well as all of its many elements). Our dissection of the garter snake begins next week, and we will have more of an idea of what information regarding these structures we want to include then. We will link information about these three structures to their respective pages. We did find one new source since last week that we would like to include, which I have included here:
Kardong, Kenneth V. (2015). Vertebrates: Comparative Anatomy, Function, Evolution (7th ed.). New York: McGraw Hill. ISBN 9780078023026 [10]
We will try to get other photographs of the rest of the garter snake anatomy, but will be focusing on these specific regions. If you have any recommendations for us, we'd love to hear them.
Snakeskin:
From the sources that we gathered last week, I was able to find the following pertinent information regarding snakeskin. there is so much information that needs to be included on this page that is not there. As it stands right now, the article is a stub, and it really needs a lot of information that can be put into various sections in order to stand as something that is actually informative. The general group sources that we compiled last week were very helpful in finding some preliminary information on snakeskin and its many components. I pulled all of the information that I thought was informative out and compiled a list of information that can be woven into a cohesive article. All of this work has been paraphrased from the original texts to the best of my ability.
From The Encyclopedia of Snakes [3]:
From The New Encyclopedia of Snakes [4]:
From Snakes- A Natural History Talks [5]:
From Snakes: A Natural History [2]:
From Modeling of the Frictional Behaviour of the Snake Skin Covered By Anisotropic Structure Nanostructures [7]:
From Vertebrates: Comparative Anatomy, Function, Evolution [10]:
I will be drafting this information into cohesive sections that I will include on the page. If you have any recommendations for me, or any sources that you think would be useful, please let me know.
Duvernoy's Gland: Mackessey et. al. suggest Duvernoy’s gland does secrete venom and is homologous to the venom gland found in front-fanged snakes. The evolutionary path of these separate glands may come from “venom proteins” whose genes are widely expressed in tissues of both venomous and non-venomous snakes. These genes are overexpressed in the venom glands (including Duvernoy’s gland), indicating the secretions from these glands evolved separately, rather than sequentially. [11] Murry4329 ( talk) 04:22, 18 March 2017 (UTC)
Vormeronasal Organ:
Both sources Snakes A Natural History [2] and Snakes - A Natural History [5] talk briefly about functions of the vomeronasal organ. The male snakes use it as a preliminary sexual attraction. The vomeronasal organ is able to detect the sense by tongue flicking action of the snake. However, if the tip of the tongue is cut off, the snake will lose its primary tool to detect the chemo cues in the environment; thus improving the important of the vomeronasal organ.
Furthermore, I plan to describe the anatomy of the organ in reptiles and its relative position to other organs. In most of the reptiles, the organ is located ventrally to the nasal chamber in which part of it concaves dorsally with a duct connect to the mouth ventrally [12]
Moreover, I will focus on how the tongue flicking behavior in the snake attracts the chemoreceptors to the vomeronasal organ [10] then compared this mechanism to that of the dog.
I will be adding all these information to the vomeronasal organ Wiki page under the section of "Animals" for snakes as well as a cut section view of the organ. For the Garter snake Wiki page, I tend to add a sub-section about tongue flicking behavior as it has not been mentioned in the page at all.
Team Perch:
A dorsal fin is classified as a medial, unpaired fin that is located on the dorsal side of aquatic vertebrates. In bony fish, fins are made of dermal fin rays known as lepidotrichia, and an endoskeletal base with associated muscles for movement. [5] During embryogenesis, the dorsal fin and other medial fins are derived from the caudal fin fold, which is itself made of a mix of peridermis and epidermis. [5] Larval development and skeletogenesis of the median fins of adult teleost fish results in pterygiophores, which are the internal skeletal elements that support the fin. [3] The pterygiophores have proximal, medial, and distal portions. The distal portions are comprised of cartilage, whereas the elongated proximal and medial portions are made of bone. [3]These serve as attachments points for expaxial muscle, which ultimately works to aid in mobility. [3]
Over all, your draft seems complete, concise, and your sources seem to provide neutral information. At this point, I would suggest fleshing out this article more, as this seems like an awfully small amount of information for such an important differentiation of analogous structures. You definitely have me hooked in and following what you’re describing, but I want to know more. Really think on what information is still lacking from this piece. Further, everything seems to be appropriately cited.
Do you have plans for pictures of any of these structures if they are not already included? I ask particularly for the pterygiophores. You spend a significant amount of time discussing these, but I'm having a difficult time visualizing them from the text alone. I would look into that if it is a possibility.
Define what dorsal is, or maybe link to a page that defines dorsal. Make sure you include links to other technical biological language that may not be self-evident for the general public. Do the same for proximal, medial, and distal in the later portions of your paragraph.
I definitely think this is a great start to editing the available information on the dorsal fin!
Ctenoid scales, similar to other epidermal appendages, originate from placodes, and specific cellular differentiation makes them exclusive from other appendages that arise from the integument. [6] The developmental process begins with an accumulation of fibroblasts between the epidermis and dermis, forming the papillae. [6] After more differentiation, collagen fibrils start to organize themselves in the dermal layer, which leads to the initiation of mineralization. [6] The circumference of the scales grows first, followed by thickness when overlapping layers mineralize together. [6]
Everything appears to be appropriately cited. The content appears neutral, concise, and informative. Everything is phrased in a way that is logical and makes sense.
If you can, provide links to scientific or biological words that may not be self-explanatory, such as papillae or integument. Normal, every-day people may not know what those are off hand.
I’m definitely on board with you wanting to include a clear picture of a ctenoid scale. It will really tie your description in and provide good visual cues, especially if you label the image with a numbered pin system (if possible).
I like the overall trajectory of your project, and it seems like you have a really good plan to work off of.
The operculum has many components that have different positions and anatomical and morphological appearances. There is the preoperculum, operculum, suboperculum, and the interoperculum. In smaller species, these components are more basic in relation to their placement in larger species where they are tubercle. [7] The pre-operculum is crescent-shaped in all Halecomorphi, which are known to be bony fish (minus the Parasemionotiformes species). [7] Parasemionotiformes pre-operculum anatomy differs in its ovoid shape and is known to be long and narrow. [7] The operculum is the largest bone out of the other components. It is broad, rectangular in shape, and has circular-shaped dorsal margins. [7] Its ventral margins are oriented anteriorly where the suboperculum is ventral from its position. [7] The pre-operculum also has a series of ridges that are directed posterodorsally to the organism’s canal pores. [7] The sub-operculum has long, concave shaped dorsal margins and convex posterior margins associated with this bone. [7] It has very short anterodorsal and anteroventral margins and boarders the operculum dorsally. [7] The inter-operculum is triangular shaped and boarders the suboperculum posterodorsally and the preoperculum anterodorsally. [7] It is also known to be short on the dorsal and ventral surrounding boarders. [7]
All of the information appears to be concise and neutral. It is super informative, and I am in complete agreement that there needs to be an image or multiple images included about the operculum and its many regions. Without the image, making a mental map off of the included paragraph itself would be difficult. Further, everything seems to be appropriately cited.
I would suggest moving your definition of what the operculum actually is to the top of your section so that people know what they’re reading about from the beginning. As it currently stands, I wouldn’t know that the operculum was a bone until midway through the paragraph.
Try to link as much of the scientific and anatomical terms as you can to pages where they might be defined (if you are not going to define them yourself). I had a hard time following the information you included because there wasn’t a lot of every-day language being used. Try to make this more approachable for the general public.
Overall, this is a really information-rich paragraph, and I like the trajectory that you have for your project!
Team Iguana:
I'd like to expand on the Reptile page (that I'd add a link to on the Iguana page), or create a section on the Iguana page itself regarding the anatomy/structure of the Iguana heart, specifically going into more detail on the muscles that are involved with the heart.
All of my sources could provide useful information, but my primary source that seems to be the most helpful is my third reference.
· It speaks of the reptile heart generally and is also specific for the Iguana heart, comparing hearts between different lizards, describing function and reason for anatomy and structures, clear/useful pictures, relationship between the anatomy and physiology of the heart, why this anatomy was favored evolutionarily, etc.
· http://vetmed.illinois.edu/mmitch/pdf/reptilecardiology.pdf
A new source I found discusses more general reptile heart anatomy and function, discussing the muscular ridges that divide the subchambers in the heart
· http://veterinarycalendar.dvm360.com/reptilian-cardiovascular-anatomy-and-physiology-evaluation-and-monitoring-proceedings
All of this information appears to be neutral. You appear to have appropriate citations, as well. I would recommend embedding these new sources into a reference list if you haven't already, and citing this information in your sandbox. The information that you want to add seems to be very informative, and that initial new source that you write about seems like it would be a very useful reference that you should use. I think it is a good idea to link the reptile page to the iguana page if that is not already in existence.
Overall, I like the trajectory of your project and think that this is a really good game plan to be following!
I would like to add more to the dewlap page about the color of the dewlap and how it forms from carotenoid and pterin pigments. (http://www.sciencedirect.com/science/article/pii/S1096495906002612) There is some information on the coloration of the dewlap on the page, but not much. I would also like to take this subject and talk more about WHY the coloration is the way it is, both of these articles go into all of that.(http://www.jstor.org/stable/1563454?seq=1#page_scan_tab_contents).
I would also like to add more to the mechanics of the reptile dewlap (http://www.sciencedirect.com/science/article/pii/S0166432805800828), since the dewlap page doesn't seem to discuss the mechanics of reptile's dewlap at all. I would simply give a brief overview of the anatomy/structure, this could connect back to Courtney and Mikayla's articles on the muscles and the skeletal structure.
Overall, this information appears to be neutral, and its great that you have these links included. I would recommend making formal citations for these in a reference list somewhere if you have not already. This might make it simpler for both you and your other group members to use these sources in the future. The information seems like it would be informative and concise, and I like that you are interested in approaching the "why" question of the coloration of the dewlap.
I noticed that you haven't included plans to search the evolutionary history of the dewlap, and that might be something that you could look into or contribute to as a way to link to what we're learning about in class evolutionarily to what you're learning anatomically.
I overall think this is a great start and that you have a good plan to follow!
I will add a subsection to the Anatomy/Physiology section, focusing on aspects of the skeletal structure. This will also help organize this section, as the information present is sparse and scattered.
Bones/Structures I would like to focus on:
Skull: I would look at anything that would distinguish the iguana from other species of lizards; plus, I would be able to simultaneously research dewlap bone function. http://archeozoo-archeobota.mnhn.fr/IMG/pdf/bochaton_et_al._in_press_iguana.pdf; http://www.jstor.org/stable/pdf/40664967.pdf (plus the other two resources indicated by me previously).
Dewlap: It is thought that the hyoid bone/skeleton is the mechanism behind dewlap extension in the Anolis equestris, a lizard in the same family as the green iguana. https://eurekamag.com/pdf.php?pdf=007364568
I think that focusing on these aspects of the skeletal system will relate very well to the work of my teammates as well. Courtney would be able to provide input regarding the muscles surrounding the dewlap/its function, and Lexie and I could collaborate on how to simultaneously examine the dewlap from different angles (Me skeletal structure, her more of the mechanism/function).
Finally, I would like to compile the above information in an integrative, yet concise manner. My teammates will also provide valuable information regarding my topic.
Overall, this information is presented as neutral. I like that you have included sources that you would like to use here, and I would suggest compiling these into a reference list in your sandbox if you have not already done so. The information you plan to include seems informative and relatively easy to understand from the perspective of the general public. I also like that you have chosen a really integrative approach to your project with your teammates. Overall, it seems like you have a good project trajectory and a great game plan.
I didn't see anything mentioned about including pictures of these structures. If they are not already well-represented, you should consider taking your own photos and using them to enhance the iguana page.
Sara:
Based on feedback from my classmates and Dr. Schutz, there are some clear steps that I need to take to edit my draft.
Ryan:
Based on feedback from classmates and Dr. Schutz:
Huy:
Below are some suggestions for improvement after looking at comments from Dr. Schutz and my classmates:
Garter Snake:
For the Garter snake page, we have begun to assemble photographs of the various organs and integument elements that we are investigating. I have photographed the scales and soft integument of the garter snake, both the large scutes of the ventral surface and the small scales that cover the rest of the body. Ryan, with Dr. Schutz’s help, successfully dissected out Duvernoy’s Gland, and has photographed it. Huy will begin his dissection of the vomeronasal organ next week, and will photograph it for inclusion on the page. When we have completed our individual topics, we will link them to the Garter snake page.
Snakeskin:
For the second draft, I’ve started to compose my sections for the snakeskin page. I went back to the reptile page to make sure that there was no overlapping information about skin. The only information included on the reptile page was about the scales of reptiles, and not the soft integument and the many functions it provides, so there is limited overlap (if any). I searched for some more journal articles about snakeskin and its evolutionary history, but came up short, either because the literature went too far over my head or was more concerned with experiments that did not relate to snakeskin in a way that was useful to my project. I also took photographs with the dissection microscope of the skin of a garter snake up close. I took a few of the skin as it appeared originally with the scales attached, a few with the large scutes removed or pulled back away from the skin, and a few photographs of the skin after removing the small overlying epidermal scales. The purpose of these photographs will serve to draw attention to the fact that snakeskin is more than just scales. I still need to work on creating sub headings, and I'm at a little bit of an impasse with the evolution section for the snakeskin. I'm considering leaving this section out because I cannot find enough sources about the evolution of snakeskin to warrant its own section. Instead, I'm considering including a brief blurb about the phylogeny of snakes at the end and linking to the Lepidosauria and Squamata pages to emphasize what groups include this sort of skin. Likewise, I am thinking of linking both the Squamata and Lepidosauria pages, as well as the snake page to the Snakeskin page once it has been edited to include the following information. I would also like to link the Snakeskin page to the Ecdysis page, and back link that page to the snake page to include snake molting without rewriting what is already included on Wikipedia.
Here are the preliminary drafted sections for the snakeskin page:
Display:
Snakes can be ornately patterned. They can be striped, banded, solid, green, blue, yellow, red, black, orange, brown, spotted, or have a unique pattern all their own. These color schemes can serve may functions, including camouflage, heat absorption or reflection, or may play other, less understood roles. Melanin cells in the skin often overlap and form complex patterns and sheets that are highly recognizable. [3] Sometimes the soft integument of a snake is colored differently than their hard scales. This is often utilized as a method of predator determent. [4]
Coloration of snakes is largely due to pigment cells and their distribution. Some scales have lightly colored centers, which arise from regions with a reduced cuticle. A thinner cuticle indicates that some sensory organ is present. Scales in general are numerous and coat the epidermis, and they come in all shapes and colors. They are helpful in identification of snake species. Chromatophores in the dermis yield coloration when light shines through the corneal layer of the epidermis. There are many kinds of chromatophores. Melanophores yield brown pigmentation, and when paired with guanophores, yield grey. When paired with guanophores and lipophores, yellow results, and when guanophore and allophores are added to melanophores, red pigment results. [2] Carotenoids also help produce orange and red colors. [3] Dark snakes, dark brown or black in color, appear as such due to melanocytes that are active in the epidermis. When melanin is absent, albino individuals result. Snakes do not possess blue or green pigments. these arise from guanophores, which are also called iridocytes. These reside in the dermis. Iridocytes are also responsible for the iridescent appearance of many dark colored snakes. Males and females may show varied coloration, as might hatchlings and adults of the same species. [2]
Function:
Snakeskin, or integument, is more than just patterns and scales. Scales and patterning are hugely important to snakes, and they are derived from a soft and complex integument. Reptiles, including snakes, possess extensive keratinization of the epidermis in the form of epidermal scales. [10] A snake's epidermis is comprised of multiple layers. They have four epidermal layers in total. The outer layer of a snake's skin is shed periodically, and is therefore a temporary layer, and is highly keratinized. Beneath the outer layer is the corneal layer ( stratum corneum), which is thickened and flexible. Under the corneal layer is intermediary zone ( stratum granulosum) and the basal layer ( stratum basale), respectively. The dermis of a snake resides beneath the epidermis. [2] The dermis of snakes is generally fibrous in nature, and not very prominent. [10]The dermis houses pigment cells, nerves, and collagen fibers. Nerve fibers extend into the snake epidermis and anchor near scales, generally at the rostral end of the snake. Specifically, nerves anchor to sensory spines and pits, which are touch and thermal detection organs, respectively. The hypodermis is below the dermis. This layer mainly stores fat. [2] Molting is common, and results in the entire outer layer of epidermis being lost. [10] For more about molting, see the Snake page. For more about the epidermal scales of the snake, see the Snake scale page.
The skin of a snake is a physically protective layer. It helps prevent injury, prevents drying out, and helps snakes to minimize friction. [5] Because snakes lack limbs, their bodies are in contact with some surface at all times, which produces a huge amount of friction. As a result, they have to both minimize friction in order to move forward, and generate their own friction in order to generate enough propulsion to move. Scale and skin orientation helps to accomplish this, and it has been demonstrated that nanostructures on their scales may play a role in this process. [7] Some snakes polish their scales. They secrete an oily substance from their nasal passage, and then rub the secretion all over the scales. This is done at varying intervals depending on the species of snake, sometimes frequently, other times only after shedding or molting. It is thought that scale polishing is used as a method of waterproofing, and it may also play a role in chemical messaging or friction reduction. [4]
Skin permeability may change seasonally in snakes to help with the problem of drying out. It is known that desert snakes have generally impermeable skins, and that aquatic snakes have a more permeable skin that can sometimes trap water to prevent drying out. Some snakes may change their environment throughout the year, and may subsequently change their skin's permeability as a result. For instance, aquatic snakes may latch on to more water if they are in an environment that is drying out by attracting a layer of water under their scales. [4]
Not many glands are present in snake skin. Most snake glands are holocrine glands, meaning that the gland's cells are secreted along with the substance the gland makes. These holocrine glands in snakes do not have their own blood supply, and thus lie closely with vascularized connective tissue. Snakes also possess glands that aid in attracting mates, and some marine snake species possess a salt gland that helps remove excess salt that they have consumed. [2] Most glands in reptiles are poorly understood due to their scarcity. [10]
The skin that lies beneath snake's scales is also responsible for snakes' flexibility. [2] The regions between snake scales is made of soft integument that allows for movement. [10]
Phylogeny:
Snakes belong to a group of reptiles called the Lepidosauria, which are reptiles with overlapping scales. They further are grouped down into the Squamata, which includes all snakes and lizards, and all but two species of Lepidosauria that belong to the Rynchocephalia (the tuatara). The species belonging to both of these subgroups likewise share similar skin features with snakes, with unique adaptations and features, respectively. [10]
Duvernoy's Gland:
Draft for addition to the function section of the article Duvernoy's gland:
Mackessey et. al. suggest Duvernoy’s gland does secrete venom and is homologous to the venom gland found in front-fanged snakes. The evolutionary path of these separate glands may come from “venom proteins” whose genes are widely expressed in tissues of both venomous and non-venomous snakes. These genes are over-expressed in the venom glands (including Duvernoy’s gland), indicating the secretions from these glands evolved separately, rather than sequentially. [11]
I am considering splitting this into two parts and adding some of it, as well as other parts of the already existing page, into a new subsection on the article Duvernoy's gland that includes the evolution of this structure.
I will also be adding photo's of Duvernoy's gland to the article, once I can get the ones I took from my dissection.
In addition to this, I will be using information from the Handbook of Venoms and Toxins of Reptiles [13] in order to further look at the anatomy and functions of Duvernoy's gland.
Vomeronasal Organ:
I will start dissecting the vomeronasal organ and taking some photos next week. After that, I will incorporate the pictures into the Wiki page of the vomeronasal organ as well as garter snake. I will only talk a little bit about how the association between the snake's tongue and the vomeronasal organ. On the wiki page of the garter snake, I will add this information under the "Behavior" section since this section talks about pheromones and mating which will connect to the vomeronasal organ.
Draft 2:
In addition to the main olfactory system, garter snakes also have the vomeronasal system which consists of the vomeronasal organ. The vomeronasal organ plays an important role in some vertebrates with its sensitivity toward chemicals that are related to mating or sensing prey. For example, the snakes use the organ to detect the presence of prey or predator by gathering the chemical cues in the environment through the flicking behavior of the forked tongue. Particularly, there should be a distinction made between the odors and vomodors. Odors are chemicals detected by the sensory cells in the nasal epithelium through the process of olfaction. Vomodors are chemicals detected by the sensory cells from the vomeronasal organ through the process of vomerolfaction. [10] Upon entering the lumen of the organ, the chemical molecules will come into contact with the sensory cells which are attached to the neurosensory epithelium of the vomeronasal organ. [14] More importantly, a new research has demonstrated that the vomeronasal organ is necessary in order for garter snake to response to airborne prey odors, but fail to respond to airborne nonprey odors. [6]
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Newmansr. You can use it for testing or practicing edits. This is not the sandbox where you should draft your assigned article for a dashboard.wikiedu.org course. To find the right sandbox for your assignment, visit your Dashboard course page and follow the Sandbox Draft link for your assigned article in the My Articles section. |
References:
Relevance to the topic:
Distracting Information:
Neutrality:
Source Neutrality:
Viewpoint Representation:
Citation Link Function
Plagiarism and Close-Paraphrasing
Out-of-Date Information
Missing Information
New Text: Many domesticated bird species have crest feathers. These structures are known to have two origins: selective breeding or mutations. Crest feathers in domestic birds include a wide range of variations in form across species. The underlying molecular and genetic mechanisms that are responsible for crest feather formation in domesticated bird species are not well-understood. As such, crest feathers are widely studied in morphological research and other related biological disciplines, particularly concerning domesticated species. [1]
- I'm interested in dissecting the iguana because it is an animal that I do not know very much about and would like to explore in depth. I'm interested in dissecting the garter snake because they were a big part of my childhood, and also because I'm interested in exploring the anatomy of an animal with a secondary loss of some feature, such as the snake's loss of limbs.
- Possible page edits: Brumation Dormancy#Brumation, Tetrodotoxin Tetrodotoxin, Heterothermy Heterothermy
- I'm interested in dissecting the iguana because it is an animal that I do not know very much about and would like to explore in depth.
- Possible page edits: Iguana Iguana, Parietal Eye Parietal eye, Dewlap Dewlap, Tympanum Tympanum (anatomy)
- I'm interested in dissecting the frog because it's an organism that I have some experience with, but not with any precise instruction or dissection. I'm interested in learning more about the frog, and applying new knowledge to an organism I already have a base with.
Our group, the garter snake, has collectively decided that we should work together to add information about the Garter snake's anatomy to it's specific page. We will attempt to take our own photographs of the Garter Snake, and try to flesh out the page as much as we can with respect to anatomical topics. We will link to the Snake when applicable, and may draw from sources listed on the snake site.
Aside from just working on the garter snake's page itself, our group has decided to undertake individual pages that relate to the Integumentary system of the snake.
My Sandbox will serve as the group's sandbox page, and all of our collective work can be found here /info/en/?search=User:Newmansr/sandbox?veaction=edit§ion=4
Sara, me, will be independently responsible for researching and adding to information about the Skin of the snake ( Snakeskin). So far, the major information on Wikipedia about snake's skin is either fashion related, or has to deal almost exclusively with Snake scales. Very little is listed regarding the snakes actual soft integument. Other information that I will try to study about the snake's skin includes shedding of the skin, skin pigmentation, skin structure and function, and it's attachment to underlying muscle.
Ryan will be researching Duvernoy's gland independently. A lot of good sources are already listed on the page itself, but very little applicable information has been included on the page. He will be working to improve the page with it's existing references and new ones.
Huy will be researching Vomeronasal organ, also known as Jacobson's organ, and the sense organs of the garter snake. He hopes to be able to dissect out our garter snake's Jacobson's organ and include an actual photograph of the structure, and not just a drawing, on the page. He also wants to improve the information that is present on the page.
Group References:
- Bauchot, Roland. Snakes: A Natural History. New York: Sterling Pub., 1994. Print. [2]
- Mattison, Christopher. The Encyclopaedia of Snakes. London: Blandford, 1995. Print. [3]
- Mattison, Christopher. The New Encyclopedia of Snakes. Princeton: Princeton University Press, 2007. Print. [4]
- Parker, H.W. Snakes - A Natural History Talks. London: Cornell University Press, 1977. Print. [5]
- "Different effects of lesions of the vomeronasal and olfactory nerves of garter snake (Thamnophis sirtalis) responses to airborne chemical stimuli (PDF Download Available)" ResearchGate. Retrieved 2017-03-11. [6]
Garter Snake Talk Page Post:
This page already has some great content on it, but I've noticed that there isn't much on the anatomy of the garter snake itself. Myself and two of my classmates are proposing to add an anatomy section to this page with linking subjects that already exist on the snake page. We want to further add to content that already exists on the page if possible as we undergo this endeavor. We plan to include photographs of the anatomy of the garter snake that come from public domain, and have a list of some proposed sources for page content that we would like to use to cover some of the basics. Photographs would be generated by ourselves as we dissect a garter snake in class. Our initial proposed sources are as follows:
-Bauchot, Roland. Snakes: A Natural History. New York: Sterling Pub., 1994. Print. [2]
- Mattison, Christopher. The Encyclopaedia of Snakes. London: Blandford, 1995. Print. [3]
- Mattison, Christopher. The New Encyclopedia of Snakes. Princeton: Princeton University Press, 2007. Print. [4]
- Parker, H.W. Snakes - A Natural History Talks. London: Cornell University Press, 1977. Print. [5]
If you think these would be good sources to begin with, please let me know. If you can point us in the direction of other useful sources that you are aware of, or other additions that you think would benefit the page that are along these lines, that information would also be helpful. Any input you have on our endeavor for this project would be useful, thank you.
Snakeskin Talk Page Post:
This page has a lot of potential, and I'd like to proposed adding to it. So far, there are not many sources for this page, and I'd like to propose a few that may be useful:
-Filippov, Alexander E., and Stanislav N. Gorb. "Modelling of the Frictional Behaviour of the Snake Skin Covered by Anisotropic Surface Nanostructures." Nature News. Nature Publishing Group, 23 Mar. 2016. Web. 10 Mar. 2017. < http://www.nature.com/articles/srep23539>. [7]
-Bauchot, Roland. Snakes: A Natural History. New York: Sterling Pub., 1994. Print. [2]
- Mattison, Christopher. The Encyclopaedia of Snakes. London: Blandford, 1995. Print. [3]
- Mattison, Christopher. The New Encyclopedia of Snakes. Princeton: Princeton University Press, 2007. Print. [4]
- Parker, H.W. Snakes - A Natural History Talks. London: Cornell University Press, 1977. Print. [5]
With the help of these sources, I would like to add information about the soft integument of snake skin to this page, as there is limited information about this on Wikipedia at present. Most of the information that I could find about §snakeskin has been about §snake scale, rather, and I think exploring snake skin on its own is important. It has a vital function, and I think it deserves some attention. it is a critical piece of §snake anatomy and is not well addressed. Further, I would like to add information to this page about snake skin §pigmentation or coloration, which may link to §albinism or §melanin or other such §pigments that contribute to the color of snakes.
Please let me know if you think these sources are appropriate, or if you can think of other sources or content areas that might be worth addressing as I endeavor to improve this page.
Duvernoy's Gland Talk Page Post:
Considering using the current sources on this page to flesh out this article. Further sources may be used in the future as I find them/gain access to them. Kenneth Kardong, who wrote three of the current sources, has additional articles related to Duvernoy's gland which I am currently trying to access Murry4329 ( talk) 04:29, 11 March 2017 (UTC)
Vomeronasal Organ Talk Page Post:
The Wiki page of the structure has a great amount of information already. However, there is only one sentence about how snakes use the vomeronasal organ and it's not even cited. I'll look for sources to add to that and expand more on that section if possible. Since I'm going to dissect a garter snake, I'm planning to add an image of the organ from my project as well. Is that possible? The listed sources below can be used in my projects:
Bauchot, Roland (1994). Snakes A Natural History. Spain: Sterling Publishing. pp. 52–56. ISBN 0806906545. [2]
Mattison, Christopher (2007). The New Encyclopedia of Snakes. Princeton University Press. p. 44. ISBN 9780691132952. [4]
Parker, H. (1977). Snakes - A Natural History Talks. Cornell University Press. p. 28. ISBN 0801491649. [5]
Garter Snake:
In thinking about the anatomical information that we want to add to this page, we've begun to make a plan regarding what pieces of anatomy we want to include in depth. We will be focusing on Duvernoy's gland, which is responsible for venom production, the Vomeronasal Organ (also known as Jacobson's organ), which is responsible for sense of smell, and the skin of the Garter Snake (as well as all of its many elements). Our dissection of the garter snake begins next week, and we will have more of an idea of what information regarding these structures we want to include then. We will link information about these three structures to their respective pages. We did find one new source since last week that we would like to include, which I have included here:
Kardong, Kenneth V. (2015). Vertebrates: Comparative Anatomy, Function, Evolution (7th ed.). New York: McGraw Hill. ISBN 9780078023026 [10]
We will try to get other photographs of the rest of the garter snake anatomy, but will be focusing on these specific regions. If you have any recommendations for us, we'd love to hear them.
Snakeskin:
From the sources that we gathered last week, I was able to find the following pertinent information regarding snakeskin. there is so much information that needs to be included on this page that is not there. As it stands right now, the article is a stub, and it really needs a lot of information that can be put into various sections in order to stand as something that is actually informative. The general group sources that we compiled last week were very helpful in finding some preliminary information on snakeskin and its many components. I pulled all of the information that I thought was informative out and compiled a list of information that can be woven into a cohesive article. All of this work has been paraphrased from the original texts to the best of my ability.
From The Encyclopedia of Snakes [3]:
From The New Encyclopedia of Snakes [4]:
From Snakes- A Natural History Talks [5]:
From Snakes: A Natural History [2]:
From Modeling of the Frictional Behaviour of the Snake Skin Covered By Anisotropic Structure Nanostructures [7]:
From Vertebrates: Comparative Anatomy, Function, Evolution [10]:
I will be drafting this information into cohesive sections that I will include on the page. If you have any recommendations for me, or any sources that you think would be useful, please let me know.
Duvernoy's Gland: Mackessey et. al. suggest Duvernoy’s gland does secrete venom and is homologous to the venom gland found in front-fanged snakes. The evolutionary path of these separate glands may come from “venom proteins” whose genes are widely expressed in tissues of both venomous and non-venomous snakes. These genes are overexpressed in the venom glands (including Duvernoy’s gland), indicating the secretions from these glands evolved separately, rather than sequentially. [11] Murry4329 ( talk) 04:22, 18 March 2017 (UTC)
Vormeronasal Organ:
Both sources Snakes A Natural History [2] and Snakes - A Natural History [5] talk briefly about functions of the vomeronasal organ. The male snakes use it as a preliminary sexual attraction. The vomeronasal organ is able to detect the sense by tongue flicking action of the snake. However, if the tip of the tongue is cut off, the snake will lose its primary tool to detect the chemo cues in the environment; thus improving the important of the vomeronasal organ.
Furthermore, I plan to describe the anatomy of the organ in reptiles and its relative position to other organs. In most of the reptiles, the organ is located ventrally to the nasal chamber in which part of it concaves dorsally with a duct connect to the mouth ventrally [12]
Moreover, I will focus on how the tongue flicking behavior in the snake attracts the chemoreceptors to the vomeronasal organ [10] then compared this mechanism to that of the dog.
I will be adding all these information to the vomeronasal organ Wiki page under the section of "Animals" for snakes as well as a cut section view of the organ. For the Garter snake Wiki page, I tend to add a sub-section about tongue flicking behavior as it has not been mentioned in the page at all.
Team Perch:
A dorsal fin is classified as a medial, unpaired fin that is located on the dorsal side of aquatic vertebrates. In bony fish, fins are made of dermal fin rays known as lepidotrichia, and an endoskeletal base with associated muscles for movement. [5] During embryogenesis, the dorsal fin and other medial fins are derived from the caudal fin fold, which is itself made of a mix of peridermis and epidermis. [5] Larval development and skeletogenesis of the median fins of adult teleost fish results in pterygiophores, which are the internal skeletal elements that support the fin. [3] The pterygiophores have proximal, medial, and distal portions. The distal portions are comprised of cartilage, whereas the elongated proximal and medial portions are made of bone. [3]These serve as attachments points for expaxial muscle, which ultimately works to aid in mobility. [3]
Over all, your draft seems complete, concise, and your sources seem to provide neutral information. At this point, I would suggest fleshing out this article more, as this seems like an awfully small amount of information for such an important differentiation of analogous structures. You definitely have me hooked in and following what you’re describing, but I want to know more. Really think on what information is still lacking from this piece. Further, everything seems to be appropriately cited.
Do you have plans for pictures of any of these structures if they are not already included? I ask particularly for the pterygiophores. You spend a significant amount of time discussing these, but I'm having a difficult time visualizing them from the text alone. I would look into that if it is a possibility.
Define what dorsal is, or maybe link to a page that defines dorsal. Make sure you include links to other technical biological language that may not be self-evident for the general public. Do the same for proximal, medial, and distal in the later portions of your paragraph.
I definitely think this is a great start to editing the available information on the dorsal fin!
Ctenoid scales, similar to other epidermal appendages, originate from placodes, and specific cellular differentiation makes them exclusive from other appendages that arise from the integument. [6] The developmental process begins with an accumulation of fibroblasts between the epidermis and dermis, forming the papillae. [6] After more differentiation, collagen fibrils start to organize themselves in the dermal layer, which leads to the initiation of mineralization. [6] The circumference of the scales grows first, followed by thickness when overlapping layers mineralize together. [6]
Everything appears to be appropriately cited. The content appears neutral, concise, and informative. Everything is phrased in a way that is logical and makes sense.
If you can, provide links to scientific or biological words that may not be self-explanatory, such as papillae or integument. Normal, every-day people may not know what those are off hand.
I’m definitely on board with you wanting to include a clear picture of a ctenoid scale. It will really tie your description in and provide good visual cues, especially if you label the image with a numbered pin system (if possible).
I like the overall trajectory of your project, and it seems like you have a really good plan to work off of.
The operculum has many components that have different positions and anatomical and morphological appearances. There is the preoperculum, operculum, suboperculum, and the interoperculum. In smaller species, these components are more basic in relation to their placement in larger species where they are tubercle. [7] The pre-operculum is crescent-shaped in all Halecomorphi, which are known to be bony fish (minus the Parasemionotiformes species). [7] Parasemionotiformes pre-operculum anatomy differs in its ovoid shape and is known to be long and narrow. [7] The operculum is the largest bone out of the other components. It is broad, rectangular in shape, and has circular-shaped dorsal margins. [7] Its ventral margins are oriented anteriorly where the suboperculum is ventral from its position. [7] The pre-operculum also has a series of ridges that are directed posterodorsally to the organism’s canal pores. [7] The sub-operculum has long, concave shaped dorsal margins and convex posterior margins associated with this bone. [7] It has very short anterodorsal and anteroventral margins and boarders the operculum dorsally. [7] The inter-operculum is triangular shaped and boarders the suboperculum posterodorsally and the preoperculum anterodorsally. [7] It is also known to be short on the dorsal and ventral surrounding boarders. [7]
All of the information appears to be concise and neutral. It is super informative, and I am in complete agreement that there needs to be an image or multiple images included about the operculum and its many regions. Without the image, making a mental map off of the included paragraph itself would be difficult. Further, everything seems to be appropriately cited.
I would suggest moving your definition of what the operculum actually is to the top of your section so that people know what they’re reading about from the beginning. As it currently stands, I wouldn’t know that the operculum was a bone until midway through the paragraph.
Try to link as much of the scientific and anatomical terms as you can to pages where they might be defined (if you are not going to define them yourself). I had a hard time following the information you included because there wasn’t a lot of every-day language being used. Try to make this more approachable for the general public.
Overall, this is a really information-rich paragraph, and I like the trajectory that you have for your project!
Team Iguana:
I'd like to expand on the Reptile page (that I'd add a link to on the Iguana page), or create a section on the Iguana page itself regarding the anatomy/structure of the Iguana heart, specifically going into more detail on the muscles that are involved with the heart.
All of my sources could provide useful information, but my primary source that seems to be the most helpful is my third reference.
· It speaks of the reptile heart generally and is also specific for the Iguana heart, comparing hearts between different lizards, describing function and reason for anatomy and structures, clear/useful pictures, relationship between the anatomy and physiology of the heart, why this anatomy was favored evolutionarily, etc.
· http://vetmed.illinois.edu/mmitch/pdf/reptilecardiology.pdf
A new source I found discusses more general reptile heart anatomy and function, discussing the muscular ridges that divide the subchambers in the heart
· http://veterinarycalendar.dvm360.com/reptilian-cardiovascular-anatomy-and-physiology-evaluation-and-monitoring-proceedings
All of this information appears to be neutral. You appear to have appropriate citations, as well. I would recommend embedding these new sources into a reference list if you haven't already, and citing this information in your sandbox. The information that you want to add seems to be very informative, and that initial new source that you write about seems like it would be a very useful reference that you should use. I think it is a good idea to link the reptile page to the iguana page if that is not already in existence.
Overall, I like the trajectory of your project and think that this is a really good game plan to be following!
I would like to add more to the dewlap page about the color of the dewlap and how it forms from carotenoid and pterin pigments. (http://www.sciencedirect.com/science/article/pii/S1096495906002612) There is some information on the coloration of the dewlap on the page, but not much. I would also like to take this subject and talk more about WHY the coloration is the way it is, both of these articles go into all of that.(http://www.jstor.org/stable/1563454?seq=1#page_scan_tab_contents).
I would also like to add more to the mechanics of the reptile dewlap (http://www.sciencedirect.com/science/article/pii/S0166432805800828), since the dewlap page doesn't seem to discuss the mechanics of reptile's dewlap at all. I would simply give a brief overview of the anatomy/structure, this could connect back to Courtney and Mikayla's articles on the muscles and the skeletal structure.
Overall, this information appears to be neutral, and its great that you have these links included. I would recommend making formal citations for these in a reference list somewhere if you have not already. This might make it simpler for both you and your other group members to use these sources in the future. The information seems like it would be informative and concise, and I like that you are interested in approaching the "why" question of the coloration of the dewlap.
I noticed that you haven't included plans to search the evolutionary history of the dewlap, and that might be something that you could look into or contribute to as a way to link to what we're learning about in class evolutionarily to what you're learning anatomically.
I overall think this is a great start and that you have a good plan to follow!
I will add a subsection to the Anatomy/Physiology section, focusing on aspects of the skeletal structure. This will also help organize this section, as the information present is sparse and scattered.
Bones/Structures I would like to focus on:
Skull: I would look at anything that would distinguish the iguana from other species of lizards; plus, I would be able to simultaneously research dewlap bone function. http://archeozoo-archeobota.mnhn.fr/IMG/pdf/bochaton_et_al._in_press_iguana.pdf; http://www.jstor.org/stable/pdf/40664967.pdf (plus the other two resources indicated by me previously).
Dewlap: It is thought that the hyoid bone/skeleton is the mechanism behind dewlap extension in the Anolis equestris, a lizard in the same family as the green iguana. https://eurekamag.com/pdf.php?pdf=007364568
I think that focusing on these aspects of the skeletal system will relate very well to the work of my teammates as well. Courtney would be able to provide input regarding the muscles surrounding the dewlap/its function, and Lexie and I could collaborate on how to simultaneously examine the dewlap from different angles (Me skeletal structure, her more of the mechanism/function).
Finally, I would like to compile the above information in an integrative, yet concise manner. My teammates will also provide valuable information regarding my topic.
Overall, this information is presented as neutral. I like that you have included sources that you would like to use here, and I would suggest compiling these into a reference list in your sandbox if you have not already done so. The information you plan to include seems informative and relatively easy to understand from the perspective of the general public. I also like that you have chosen a really integrative approach to your project with your teammates. Overall, it seems like you have a good project trajectory and a great game plan.
I didn't see anything mentioned about including pictures of these structures. If they are not already well-represented, you should consider taking your own photos and using them to enhance the iguana page.
Sara:
Based on feedback from my classmates and Dr. Schutz, there are some clear steps that I need to take to edit my draft.
Ryan:
Based on feedback from classmates and Dr. Schutz:
Huy:
Below are some suggestions for improvement after looking at comments from Dr. Schutz and my classmates:
Garter Snake:
For the Garter snake page, we have begun to assemble photographs of the various organs and integument elements that we are investigating. I have photographed the scales and soft integument of the garter snake, both the large scutes of the ventral surface and the small scales that cover the rest of the body. Ryan, with Dr. Schutz’s help, successfully dissected out Duvernoy’s Gland, and has photographed it. Huy will begin his dissection of the vomeronasal organ next week, and will photograph it for inclusion on the page. When we have completed our individual topics, we will link them to the Garter snake page.
Snakeskin:
For the second draft, I’ve started to compose my sections for the snakeskin page. I went back to the reptile page to make sure that there was no overlapping information about skin. The only information included on the reptile page was about the scales of reptiles, and not the soft integument and the many functions it provides, so there is limited overlap (if any). I searched for some more journal articles about snakeskin and its evolutionary history, but came up short, either because the literature went too far over my head or was more concerned with experiments that did not relate to snakeskin in a way that was useful to my project. I also took photographs with the dissection microscope of the skin of a garter snake up close. I took a few of the skin as it appeared originally with the scales attached, a few with the large scutes removed or pulled back away from the skin, and a few photographs of the skin after removing the small overlying epidermal scales. The purpose of these photographs will serve to draw attention to the fact that snakeskin is more than just scales. I still need to work on creating sub headings, and I'm at a little bit of an impasse with the evolution section for the snakeskin. I'm considering leaving this section out because I cannot find enough sources about the evolution of snakeskin to warrant its own section. Instead, I'm considering including a brief blurb about the phylogeny of snakes at the end and linking to the Lepidosauria and Squamata pages to emphasize what groups include this sort of skin. Likewise, I am thinking of linking both the Squamata and Lepidosauria pages, as well as the snake page to the Snakeskin page once it has been edited to include the following information. I would also like to link the Snakeskin page to the Ecdysis page, and back link that page to the snake page to include snake molting without rewriting what is already included on Wikipedia.
Here are the preliminary drafted sections for the snakeskin page:
Display:
Snakes can be ornately patterned. They can be striped, banded, solid, green, blue, yellow, red, black, orange, brown, spotted, or have a unique pattern all their own. These color schemes can serve may functions, including camouflage, heat absorption or reflection, or may play other, less understood roles. Melanin cells in the skin often overlap and form complex patterns and sheets that are highly recognizable. [3] Sometimes the soft integument of a snake is colored differently than their hard scales. This is often utilized as a method of predator determent. [4]
Coloration of snakes is largely due to pigment cells and their distribution. Some scales have lightly colored centers, which arise from regions with a reduced cuticle. A thinner cuticle indicates that some sensory organ is present. Scales in general are numerous and coat the epidermis, and they come in all shapes and colors. They are helpful in identification of snake species. Chromatophores in the dermis yield coloration when light shines through the corneal layer of the epidermis. There are many kinds of chromatophores. Melanophores yield brown pigmentation, and when paired with guanophores, yield grey. When paired with guanophores and lipophores, yellow results, and when guanophore and allophores are added to melanophores, red pigment results. [2] Carotenoids also help produce orange and red colors. [3] Dark snakes, dark brown or black in color, appear as such due to melanocytes that are active in the epidermis. When melanin is absent, albino individuals result. Snakes do not possess blue or green pigments. these arise from guanophores, which are also called iridocytes. These reside in the dermis. Iridocytes are also responsible for the iridescent appearance of many dark colored snakes. Males and females may show varied coloration, as might hatchlings and adults of the same species. [2]
Function:
Snakeskin, or integument, is more than just patterns and scales. Scales and patterning are hugely important to snakes, and they are derived from a soft and complex integument. Reptiles, including snakes, possess extensive keratinization of the epidermis in the form of epidermal scales. [10] A snake's epidermis is comprised of multiple layers. They have four epidermal layers in total. The outer layer of a snake's skin is shed periodically, and is therefore a temporary layer, and is highly keratinized. Beneath the outer layer is the corneal layer ( stratum corneum), which is thickened and flexible. Under the corneal layer is intermediary zone ( stratum granulosum) and the basal layer ( stratum basale), respectively. The dermis of a snake resides beneath the epidermis. [2] The dermis of snakes is generally fibrous in nature, and not very prominent. [10]The dermis houses pigment cells, nerves, and collagen fibers. Nerve fibers extend into the snake epidermis and anchor near scales, generally at the rostral end of the snake. Specifically, nerves anchor to sensory spines and pits, which are touch and thermal detection organs, respectively. The hypodermis is below the dermis. This layer mainly stores fat. [2] Molting is common, and results in the entire outer layer of epidermis being lost. [10] For more about molting, see the Snake page. For more about the epidermal scales of the snake, see the Snake scale page.
The skin of a snake is a physically protective layer. It helps prevent injury, prevents drying out, and helps snakes to minimize friction. [5] Because snakes lack limbs, their bodies are in contact with some surface at all times, which produces a huge amount of friction. As a result, they have to both minimize friction in order to move forward, and generate their own friction in order to generate enough propulsion to move. Scale and skin orientation helps to accomplish this, and it has been demonstrated that nanostructures on their scales may play a role in this process. [7] Some snakes polish their scales. They secrete an oily substance from their nasal passage, and then rub the secretion all over the scales. This is done at varying intervals depending on the species of snake, sometimes frequently, other times only after shedding or molting. It is thought that scale polishing is used as a method of waterproofing, and it may also play a role in chemical messaging or friction reduction. [4]
Skin permeability may change seasonally in snakes to help with the problem of drying out. It is known that desert snakes have generally impermeable skins, and that aquatic snakes have a more permeable skin that can sometimes trap water to prevent drying out. Some snakes may change their environment throughout the year, and may subsequently change their skin's permeability as a result. For instance, aquatic snakes may latch on to more water if they are in an environment that is drying out by attracting a layer of water under their scales. [4]
Not many glands are present in snake skin. Most snake glands are holocrine glands, meaning that the gland's cells are secreted along with the substance the gland makes. These holocrine glands in snakes do not have their own blood supply, and thus lie closely with vascularized connective tissue. Snakes also possess glands that aid in attracting mates, and some marine snake species possess a salt gland that helps remove excess salt that they have consumed. [2] Most glands in reptiles are poorly understood due to their scarcity. [10]
The skin that lies beneath snake's scales is also responsible for snakes' flexibility. [2] The regions between snake scales is made of soft integument that allows for movement. [10]
Phylogeny:
Snakes belong to a group of reptiles called the Lepidosauria, which are reptiles with overlapping scales. They further are grouped down into the Squamata, which includes all snakes and lizards, and all but two species of Lepidosauria that belong to the Rynchocephalia (the tuatara). The species belonging to both of these subgroups likewise share similar skin features with snakes, with unique adaptations and features, respectively. [10]
Duvernoy's Gland:
Draft for addition to the function section of the article Duvernoy's gland:
Mackessey et. al. suggest Duvernoy’s gland does secrete venom and is homologous to the venom gland found in front-fanged snakes. The evolutionary path of these separate glands may come from “venom proteins” whose genes are widely expressed in tissues of both venomous and non-venomous snakes. These genes are over-expressed in the venom glands (including Duvernoy’s gland), indicating the secretions from these glands evolved separately, rather than sequentially. [11]
I am considering splitting this into two parts and adding some of it, as well as other parts of the already existing page, into a new subsection on the article Duvernoy's gland that includes the evolution of this structure.
I will also be adding photo's of Duvernoy's gland to the article, once I can get the ones I took from my dissection.
In addition to this, I will be using information from the Handbook of Venoms and Toxins of Reptiles [13] in order to further look at the anatomy and functions of Duvernoy's gland.
Vomeronasal Organ:
I will start dissecting the vomeronasal organ and taking some photos next week. After that, I will incorporate the pictures into the Wiki page of the vomeronasal organ as well as garter snake. I will only talk a little bit about how the association between the snake's tongue and the vomeronasal organ. On the wiki page of the garter snake, I will add this information under the "Behavior" section since this section talks about pheromones and mating which will connect to the vomeronasal organ.
Draft 2:
In addition to the main olfactory system, garter snakes also have the vomeronasal system which consists of the vomeronasal organ. The vomeronasal organ plays an important role in some vertebrates with its sensitivity toward chemicals that are related to mating or sensing prey. For example, the snakes use the organ to detect the presence of prey or predator by gathering the chemical cues in the environment through the flicking behavior of the forked tongue. Particularly, there should be a distinction made between the odors and vomodors. Odors are chemicals detected by the sensory cells in the nasal epithelium through the process of olfaction. Vomodors are chemicals detected by the sensory cells from the vomeronasal organ through the process of vomerolfaction. [10] Upon entering the lumen of the organ, the chemical molecules will come into contact with the sensory cells which are attached to the neurosensory epithelium of the vomeronasal organ. [14] More importantly, a new research has demonstrated that the vomeronasal organ is necessary in order for garter snake to response to airborne prey odors, but fail to respond to airborne nonprey odors. [6]