User:Dr.Biology/sandbox

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Kasey's Work[edit]

Article Evaluation (Week 2)[edit]

No in-text citation to source number one. Second sentence in paragraph 1 is very poorly worded. Also in that sentence, they should mention the 5 synapomorphies and explain them better because they gave an incorrect definition of it. They should include an easier to understand phylogeny. One date of a source is 2002 which is questionably out of date. Possible plagiarism in feeding paragraph from source 8. They could add some more topics. Possible ideas are, location, reproduction, expand on feeding. They should separate the fossilized species section from the intro. Also, this is a lot less important than many other topics that were not included. Cephalochordates

Group Work (Week 3)[edit]

  • No in-text citation to source number one.
  • Sentences are poorly worded at times.
  • Unclean dendrogram. (phylogeny)
  • Inaccuracy of the 5 similarities.
  • They should mention and define the 5 synapomorphies.
  • They should elaborate on the feeding section with information like feeding sources.
  • Outdated source (2002).
  • Image improperly sourced on page.
  • Feeding section seems word for word from source 8.
  • They could add sections such as location, reproduction, morphology, and development.
  • They should separate the extinct from the extant.

Question:[edit]

In the second sentence of paragraph one, there is mention of the 5 synapomorphies present in all chordates, without the mention of the word synapomorphies. Also, the definition is not entirely correct because they do not have to be present in the adult form. Should this be addressed?

Cephalochordate edit:[edit]

In a study performed by Blair and Hedges in 2005, they used protein sequence data of 75 different proteins to determine that cephalochordates diverged from the rest of the chordate subphylum around 891million years ago.[1]

Top 3 Organisms (Week 4)[edit]

  1. Amphiuma - I'm very intrigued by the amphiuma because it is a good transition animal between limbs and no limbs. It would be interesting to learn more about that anatomically. salamander conger Sirenidae
  2. Skate - I find both the sting ray and skate vary fascinating in terms of their movement and how they function. I would like to learn more about what the differences between them are morphologically. Batoidea Rajiformes Egg case (Chondrichthyes)
  3. Sting Ray - I am interested in the sting ray because as I said I am fascinated by their movement and function. I would like to learn more than what I already know of their anatomy, reproduction, and other aspects of the sting ray. Ovoviviparity Ampullae of Lorenzini Elasmobranchii

Game Plan (Week 5)[edit]

Reproduction[edit]

  • First off, the reproduction section is very short, and could use a lot more information. The few aspects they point out are good, but could use both elaboration, and links to other pages. Many of the words necessary are present in parts, but just are not linked.
  • One aspect I would like to elaborate on is how the egg cases are formed. The egg cases are very specific to the skate. The article by mabagraña et al covers this very in depth[2].
  • Another thing I would like to elaborate on, is how and when they mate. It was very interesting reading about the use of the claspers and the process and I think this would be very beneficial information to the section. With this I would add how they hatch 15 months later, very somatically developed. Also, they mate at the same location every time[3].
  • Sources are 2 and 3 in references and also will use one on ana tomy page. The sources are linked to their page where they're at.

Draft (Week 6)[edit]

Reproduction[edit]

Skates mate at the same nursery ground each year. In order to fertilize the egg, males use claspers, a structure attached to the pelvic fins. The claspers allow them to direct the flow of semen into the female's cloaca. Skates are oviparous, meaning they lay eggs with very little development in the mother. This is one major difference from rays, which are viviparous, meaning they give birth to live young. When a female skate is fertilized, a protected case forms around the embryo called an egg case, or more commonly mermaid's purse. This egg case is then deposited out of the mothers body onto the ocean floor where the skates develop for up to 15 months before they enter the external environment.

Species Differentiation[edit]

Egg cases have distinct characteristics that are individualized to each species. This makes a great tool for identifying different species of skates. One of these identifiable structures, is the keel. The keel is a flexible ridge that runs along the outside of the structure. Another characteristic is the number of embryos in the egg case. Some species contain only one embryo while others can have up to roughly seven. The size of the fibrous shell around the case is another characteristic. Some species have thick layers on the exterior, however other species don't even have the presence of this layer.

Draft Edits (Week 7)[edit]

Stingray[edit]

  • Many typos, reread and fix.
  • I found many sentences and words that I thought were unnecessary and didn't add anything to the paper. read through and ask yourself if this sentence or adjective is needed to get the information across.
  • I felt the wording wasn't quite formal enough in a few places. It should read as a series of connected facts, it felt more like a story at times.
  • The locomotion section could use more words describing many of the big words used. It was hard to follow and understand even though it was the right information. Understand the audience.
  • Add links to information that has it. There was only a couple in the whole draft.
  • Figure out how the information is going to tie together and where on the page.
  • Otherwise, pretty good draft, just address these minor issues and sentence structure.

Pigeon[edit]

  • When referring to the bird in the neck vertebra section, refer to it as pigeon instead of bird.
  • Good edit though for the neck section, good use of sources. Consider use of links.
  • Flight section has good information, but just needs to be put into a draft. Avoid when compiling it to make it too wordy with big words.
  • More information in general should be added.
  • Figure out how the information will tie together and into the final page.
  • You make mention of things you will do but it's hard to edit what hasn't been drafted yet.

Group Work (Mckenna, Madi, & Kasey)[edit]

  • Our main plan as of now, is to edit the Skate (fish) page, by adding more information, as well as making links, to 3 sections of anatomy, reproduction, and defense.

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Reproduction (Kasey)[edit]

  • First off, the reproduction section is very short, and could use a lot more information. The few aspects they point out are good, but could use both elaboration, and links to other pages. Many of the words necessary are present in parts, but just are not linked.
  • One aspect I would like to elaborate on is how the egg cases are formed. The egg cases are very specific to the skate. The article by mabagraña et al covers this very in depth[2].
  • Another thing I would like to elaborate on, is how and when they mate. It was very interesting reading about the use of the claspers and the process and I think this would be very beneficial information to the section. With this I would add how they hatch 15 months later, very somatically developed. Also, they mate at the same location every time[3].
  • Sources are 2 and 3 in references and also will use one on ana tomy page. The sources are linked to their page where they're at.

Draft[edit]

Reproduction[edit]

Skates mate at the same nursery ground each year. In order to fertilize the egg, males use claspers, a structure attached to the pelvic fins. The claspers allow them to direct the flow of semen into the female's cloaca. Skates are oviparous, meaning they lay eggs with very little development in the mother. This is one major difference from rays, which are viviparous, meaning they give birth to live young. When a female skate is fertilized, a protected case forms around the embryo called an egg case, or more commonly mermaid's purse. This egg case is then deposited out of the mothers body onto the ocean floor where the skates develop for up to 15 months before they enter the external environment[3].

Species Differentiation[edit]

Egg cases have distinct characteristics that are individualized to each species[2][4]. This makes a great tool for identifying different species of skates. One of these identifiable structures, is the keel. The keel is a flexible ridge that runs along the outside of the structure. Another characteristic is the number of embryos in the egg case. Some species contain only one embryo while others can have up to roughly seven. The size of the fibrous shell around the case is another characteristic. Some species have thick layers on the exterior, however other species don't even have the presence of this layer.

*I plan on moving the image of the mermaids purse to this section. We will likely include this section in the Anatomy and Physiology section.

*Madi, this section might actually fit better in your section.

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Anatomy (Mckenna)[edit]

I would like to add to the anatomy and physiology portion of the article Skate (fish). And possibly create a page about a specific part of the skate that I can link to this article.

What the article contains right now:

  • A few sentences talking about the skates cartilaginous skeleton
  • placoid scales
  • paired fins
  • movable jaw.

Analysis of Section:

As of now the section talks about these traits in three sentences. It is made up of one subheading titled "External Characteristics." I would like to add more general information about each of these features as well as include more specific anatomy that is common the rays and specific to skates. I think the anatomy and physiology portion is important to orient a reader to what kind of organism they are learning about, and allow them to consider how the structure and physiology relates to other sections within the article such as Behavior and Ecology, Lifecycle, and the comparison of stingrays and skates.

Possible Additions/Improvements:

  • Add links to other wiki articles- such as linking the placoid scale to the article Fish scale that talks about placoid scales in detail, Ampullae Lorenzini, and other features to appropriate site
  • I would like to focus on ambulatory locomotion via pelvic fins, and the recent research that suggest that neural pathway/control for walking evolved earlier than thought based on the pelvic fins studied in skates.[5][6]
  • Add images from our dissection and label parts for reference
  • Add an Internal Characteristics sub heading to include features such as cartilaginous skeleton, ampullae lorenzini, its electric organs, etc. (which can pair with Madi because I believe she is focusing on this feature) and add to the existing external characteristics subheading with more detailed information and mainly images.[7]

*Side note: Kasey I found a article entry that talks about the reproduction of skates and specifically the egg structure[8]

Draft (Week 6)[edit]

Focus: Anatomy and physiology section in the Skate (fish) existing wikipedia article

For this draft I plan to focus on the external anatomy of the skate in the existing wikipedia article Skate (fish) by adding links, written information and visual images. Madi is going to focus on the internal anatomy, but we are both going to integrate our information and media to improve the anatomy and physiology information in the article. We decided as we dissect we may explore the brain together and see how we might include this into our additions and improvements of the article.

My draft to edit article will include written portion as well as:

-Add photo of skate from our dissection and then use powerpoint to label parts

-maybe a link to a video of a skate using its pelvic fins for ambulatory locomotion

-Madi and I are considering finding labeled drawings/diagrams of the skate's anatomy but we are having trouble finding an acceptable one with out a copy write issue.

Possible addition:

Skates, like rays, have a distinct flat body shape with flat pectoral fins that extend the length of their body.[9] Their body shape and large pectoral fins allow them to glide close to the floor of their habitat in search for benthic prey. Another key external characteristic of the skate is its rough skin made of placoid scales. Placoid scales have a pointed tip that is oriented caudally and are made of the same composition as teeth. The skin texture has been compared to sand paper.[9] Their mouths are located ventrally or on the underside of the body, and are made up of a moveable jaw, also assisting to their benthic feeding style. Skate's gill slits are located ventrally as well, but dorsal spiracles allow the skate to be partially buried in floor sediment and still complete respiratory exchange.[10] Also located on the dorsal side of the skate are the eyes used for the awareness of predators and other surroundings.[9] In addition to their pectoral fins, skates have a first and second dorsal fin, caudal fin and paired pelvic fins. Current research suggests that some species of skates use these pelvic fins to perform ambulatory locomotion (watch a video here) on the water floor.[11] This form of locomotion performed by the skate is being explored as a possible origin for our own development of walking by looking for similar neural pathways used for movement between skates and animals walking on land.[12]

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Defense (Madi)[edit]

I will add to section with heading titled Anatomy and physiology; create subheading called Defense and elaborate on the electric organ that skates have. The article I got the idea from was Electric organ (biology). I might also do some adding to this page as well if I find more information that is good for it. Things that will be added to the Skate page about the electric organ include:

  • physiology of the electric organ
  • purpose/importance of having it
  • morphology
  • possibly a bit of information regarding the evolution of the electric organ

From this reading, it sounds like the electric organ in the skate is used only for communication, because the discharges of their electric organs are weak and do not do anything to protect them from predators.[13] This would cause me to change the subheading from Defense to something else like Communication. Either way, this article has a lot of good information.

[1] Another good article about the mechanism of EO.

Draft (Week 6)[edit]

Mckenna and I have decided to work on the anatomy of the skate together. She will focus on the external anatomy and I will focus on the internal anatomy. Kasey is researching reproduction which will tie into both internal and external anatomy. Mckenna and I will be adding to the "Anatomy" section of the Skate page and creating out own subheadings, while Kasey will be adding to the "Reproduction" section.

Although I am still very interested in the electric organ of the skate, there is not very much information out there, specifically pertaining to the skate, that I can add to the article. Consequently, I am going to look for more aspects of the internal anatomy to talk about as well.

  • Skates are among many species of electrogenic fishes who produce weak electric organ discharges (EODs)[13]
  • The skate has small, paired electric organs in the tail that allow it to send out weak electric signals for communication[13]
  • They do not produce strong enough currents to shock anything[13]

As a group we decided to look for images online that are like cartoons or diagrams that label drawings of the skate as a reference point for readers to look at.

Then, we will take some of our own pictures once we start dissecting the skate in lab and add those to supplement the drawings. We also got the recommendation to think about dissecting the brain of the Skate and comparing it to the brain of the shark we had in lab. We plan on doing this when we dissect our skate and if there is anything interesting there to talk about then we will consider adding a section to the Skate (fish) page about the brain as well.

[1] This website has some cool pictures and descriptions of skates and rays. The pictures on this site cannot be used on Wikipedia because the copyright says commercial use is strictly prohibited, but the information is still good!

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Draft ideas for draft 2 (Week 9)[edit]

For draft 2, we plan on doing a copy edit for the sections that we are going to edit. Using this, we are going to figure out exactly where our information is going to fit in and how it is going to tie the article together.

In order to start this process hear are some overall areas we are going to focus on for next week based on our peer edits:

  • Reorganize our page so that it is easier to navigate by adding headings and then make sure our group work is clearly separate from Kasey's individual work
  • Fix copy edits/typos in each of our sections
  • Write our second drafts in the same format as the article we are editing (Skate) by using the headings and ordering our additions in the sandbox to match the order they will go in the article.
  • Continue to look for pictures to add to our sections and upload pictures we took in lab
  • Start our dissection and keep our mind open to what else we can add as we explore the skate in lab (specifically special information for the anatomy physiology section)

Kasey's Section[edit]

For my section, I plan on keeping most of it the same. A few people pointed out a few grammatical errors that I will need to fix as well as a couple spots I need to use more professional wording. Organizationally, someone recommended that on the final page we organize it by putting the anatomy and physiology section first, then putting the reproduction section after it. These two article have some links and I think would provide a smooth reading going from section to section. Also, people brought up some good ideas that I am going to research as well, such as where their nursery grounds are.

Mckenna's Section[edit]

I also plan on keeping my section the same. I have copy edits I will make, and work on wording my sentences so they are succinct and informational. As we start our dissection I would like to see what interesting topic to the skate we could include in the article and dissect in detail. Some suggestions we had were to look at the spiracle and its musculature, and also consider exploring the brain. I like both of these ideas so I think I might research them and try this. Depending on how dissection goes I might add images and information about this into the article. There was a suggestion to move my section to the beginning of the article to orient the reader to the article, but I think I am going to keep it in the anatomy section because I don't have any other type of background for the skate.

Madi's Section[edit]

I think it is a good idea for us to dissect the brain of the skate as well, but there is not really a good spot to add information onto the Skate (fish) page, but it could be cool to dissect and take pictures for the Rajiformes page, since we have access to a shark brain as well. Also, we have a female skate and we are very eager to see if we can find a mermaid's purse when we dissect, however, we have not spoken to the stingray group so we should see if they have a male that we can take pictures of the claspers on. The comparison between male and female reproductive anatomy (external) could also be something that is added to the Skate and the Rajiformes page.

Mckenna and I are both interested in looking at the general anatomy of the skate and finding specific topics we can elaborate on, but it seems like we have divided it into internal and external anatomy. Most of her focus will be on the external anatomy and mine will be on the internal anatomy. I am looking for videos to see if it is possible to dissect out the electric organs of the skate and I would like to attempt to do that and take pictures for our Wikipedia page, but I am not sure if that is possible. I also found a skate dissection video where they were looking at the the internal organs of the skate and it was pointed out that the stake has two separate stomachs. I would like to research more information about that as well. These are some things I think it would be useful to add to our draft. In response to the feedback left about my section, I think it was a good idea to look for more information on other organisms that have similar EOs to that of the skate and try to gain more information by studying those species. I will do that this week before we make our second draft as a group. As for the comment about moving the anatomy section, I think it was more of a misunderstanding. We do not plan on having the anatomy section under reproduction, it was simply that Kasey added his information first to the sandbox and he was focusing on that topic. We are simply adding to the existing topics with the corresponding headings to those we used in the sandbox.

Comments from Dr. Schutz:

  • Good job responding to the reviews and finding common patterns that led you to plan a revision.
  • As you work through your drafts, be sure to use the rubric I provided
  • Kasey, talk to me about your organizational plan. I may be able to give you some ideas. The brain is a delicate but easy dissection and could make an interesting comparison to the shark. This past week Juli dissected a very nice brain on the shark so it could make a nice comparison.
  • Examination of the electric organ could be great, but might be hard to isolate. If you cannot find it easily, you have plenty of other things to discuss.
  • Finally, good job on thinking ahead as to which pages your contributions might be best suited for!

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Draft 2 (Week 10)[edit]

Adding to Skate[edit]

  • Overall clean up of organization of page.
  • Add to photo gallery pictures from dissection for next week

Skate (Fish)[edit]

We found that the lead section was sufficient as is and does not need to be changed.

Anatomy and physiology[edit]

General batoidea characteristics[edit]

Skates are cartilaginous fishes like other Chondrichthyes, however, skates, like rays and other Rajiformes, have a flat body shape with flat pectoral fins that extend the length of their body.[9] A large portion of the skate's dorsal body is covered by rough skin made of placoid scales. Placoid scales have a pointed tip that is oriented caudally and are homologous to teeth. Their mouths are located on the underside of the body, with a jaw suspension common to Batoids known as euhyostyly.[14] Skate's gill slits are located ventrally as well, but dorsal spiracles allow the skate to be partially buried in floor sediment and still complete respiratory exchange.[10] Also located on the dorsal side of the skate are their two eyes which allow for predator awareness.[9] In addition to their pectoral fins, skates have a first and second dorsal fin, caudal fin and paired pelvic fins. Distinct from their rhomboidal shape is a long fleshy slender tail. While skate anatomy is similar to other Batoidea, features such as their electric organ and mermaids purse create clear distinctions.

Skate specific characteristics[edit]

Mermaids purse[edit]

Full view of a skate's mermaid's purse. Roughly 125 mm in length.

Skate's produce their young in an egg case called Mermaids Purse. These egg cases have distinct characteristics that are individualized to each species[2][4]. This makes a great tool for identifying different species of skates. One of these identifiable structures, is the keel. The keel is a flexible ridge that runs along the outside of the structure. Another characteristic is the number of embryos in the egg case. Some species contain only one embryo while others can have up to seven. The size of the fibrous shell around the case is another characteristic. Some species have thick layers on the exterior, however other species don't even have the presence of this layer.

Electric organ[edit]

The electric organ (EO) is a characteristic exclusive to fish. Among the Chondrichthyes, the only species to posses electric organs are the electric rays and the skates. Unlike many other electrogenic fishes, the skate is unique in that it has two paired electric organs, which run longitudinally along the tail in the lateral musculature of the vertebral column.[13] The impulses put out by the electric organs of the skate are considered to be weak, asynchronous, long-lasting signals.[15] Although the anatomy of the Skate EO is now commonly studied and well understood, there is not enough strong evidence to suggest what the actual function of the EO is. Some research suggests the electric impulses are too weak to be a mechanism used for defense or hunting, and it is also too irregular to be useful for electrolocation purposes.[15] The most reasonable explanation in the literature suggests that the electric organ discharges may be used as a form of communication. [15]

*I also intend to dissect the tail of our skate to take pictures of the electric organs. This may require use of a microscope.

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Behavior and ecology[edit]

*Copy Edit

The majority of skates feed on benthic (bottom dwelling) animals, such as shrimp, crab, oyster, clams, and other invertebrates. To feed on these animals they have grinding plates in their mouths. Filter feeding rays that eat plankton have gill rakers. Skates are an influential part of the food webs of demersal marine communities. They utilize similar resources to those of other upper trophic-level marine predators, such as seabirds, marine mammals, and sharks. The flattened body shape, ventral eyes and well developed spiracles of the the skate allows them to live benthically, buried in the sediment or using a longitudinal undulation of the pectoral fins known as Rajiform locomotion to glide along the water floor.[16] Current research suggests that some species of skates, in addition to their Rajiform locomotion, use their pelvic fins to perform ambulatory locomotion on the water floor.[11] This form of locomotion performed by the skate is being explored as a possible origin for our own development of walking by looking for similar neural pathways used for movement between skates and animals walking on land.[12]

Habitat and Distribution[edit]

*move habitat and distribution section from article here instead

Lifecycle[edit]

Reproduction (Replaces old section)[edit]

4 developing embryos located in an opened big skate egg case (mermaid's purse)

Skates mate at the same nursery ground each year. In order to fertilize the egg, males use claspers, a structure attached to the pelvic fins. The claspers allow them to direct the flow of semen into the female's cloaca. Skates are oviparous, meaning they lay eggs with very little development in the mother. This is one major difference from rays, which are viviparous, meaning they give birth to live young. When a female skate is fertilized, a protected case forms around the embryo called an egg case, or more commonly mermaid's purse. This egg case is then deposited out of the mothers body onto the ocean floor where the skates develop for up to 15 months before they enter the external environment[3].

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Gallery[edit]

The pictures are in my sandbox.

The Skate article already has a photo gallery on it and we want to add these photos to it, so they will not be directly inserted into any of the paragraphs.

Illustrating a Draft (Week 11)[edit]

We've added pictures to our Draft 2 under week 10. The pictures are intended to be with in the article, as well as additional pictures added to the existing gallery in the Skate article. See above.

Launching (week 12)[edit]

We added images to the skate page and shifted the distribution and habitats under the biology and ecology section. We are going to wait and see the response to our edits.

*to be added to Chondrichthyes anatomy section

Regions of a Chondrichthyes brain colored and labeled on dissected skate.

Nervous System[edit]

Chondrichthyes nervous system is composed of a small brain, 8-10 pairs of cranial nerves, and a spinal chord with spinal nerves[17]. They have several sensory organs which provide information to be processed. Ampullae of Lorenzini are a network of small jelly filled pores called electroreceptors which help the fish sense electric fields in water. This aids in finding prey, navigation, and sensing temperature. The Lateral line system has modified epithelial cells located externally which sense motion, vibration, and pressure in the water around them. Most subspecies have large well-developed eyes. Also, they have very powerful nostrils and olfactory organs. Their inner ears consist of 3 large semicircular canals which aid in balance and orientation. Their sound detecting apparatus has limited range and is typically more powerful at lower frequencies. Some subspecies have electric organs which can be used for defense and predation. They have relatively simple brains with the forebrain not greatly enlarged.

Week 13[edit]

  • I launched the nervous system paragraph onto the Chondrichthyes page. I plan on seeing how that goes before I add my image.
  • We added all of our other information to the Skate (fish) page.
  • We have worked on slight grammar edits in all of our text.

Final Draft (Week 14)[edit]

**Dr.Biology copied most of the material over to the live pages straight from this page but we all wrote the same amount of material.

*Added to Skate (fish) page

Anatomy and physiology[edit]

General batoidea characteristics[edit]

Skates are cartilaginous fishes like other Chondrichthyes.[18] However, skates, like rays and other Rajiformes, have a flat body shape with flat pectoral fins that extend the length of their body.[19] A large portion of the skate's dorsal body is covered by rough skin made of placoid scales. Placoid scales have a pointed tip that is oriented caudally and are homologous to teeth. Their mouths are located on the underside of the body, with a jaw suspension common to Batoids known as euhystyly.[18] Skate's gill slits are located ventrally as well, but dorsal spiracles allow the skate to be partially buried in floor sediment and still complete respiratory exchange.[20] Also located on the dorsal side of the skate are their two eyes which allow for predator awareness.[19] In addition to their pectoral fins, skates have a first and second dorsal fin, caudal fin and paired pelvic fins. Distinct from their rhomboidal shape is a long fleshy slender tail. While skate anatomy is similar to other Batoidea, features such as their electric organ and mermaids purse create clear distinctions.

Full view of a skate's mermaid's purse. Roughly 125 mm in length.

Skate specific characteristics[edit]

Mermaids purse[edit]

Skate's produce their young in an egg case called Mermaids Purse. These egg cases have distinct characteristics that are individualized to each species[21][22]. This makes a great tool for identifying different species of skates. One of these identifiable structures, is the keel. The keel is a flexible ridge that runs along the outside of the structure. Another characteristic is the number of embryos in the egg case. Some species contain only one embryo while others can have up to seven. The size of the fibrous shell around the case is another characteristic. Some species have thick layers on the exterior, however other species don't even have the presence of this layer.

Electric organ[edit]

The fibers of the skate electric organ are embedded in the muscles located lateral to the notochord in the tail.

The electric organ (EO) is a characteristic exclusive to fish. Among the Chondrichthyes, the only species to posses electric organs are the electric rays and the skates. Unlike many other electrogenic fishes, the skate is unique in that it has two paired electric organs, which run longitudinal along the tail in the lateral musculature of the notochord.[23] The impulses put out by the electric organs of the skate are considered to be weak, asynchronous, long-lasting signals.[24] Although the anatomy of the Skate EO is now commonly studied and well understood, there is not enough strong evidence to suggest what the actual function of the EO is. Some research suggests the electric impulses are too weak to be a mechanism used for defense or hunting, and it is also too irregular to be useful for electrolocation purposes.[24] The most reasonable explanation in the literature suggests that the electric organ discharges may be used as a form of communication. [24]

Behavior and ecology[edit]

Diet / Feeding[edit]

The majority of skates feed on bottom dwelling animals, such as shrimp, crab, oyster, clams, and other invertebrates. To feed on these animals they have grinding plates in their mouths. Filter feeding rays that eat plankton have gill rakers. Skates are an influential part of the food webs of demersal marine communities. They utilize similar resources to those of other upper trophic-level marine predators, such as seabirds, marine mammals, and sharks. The flattened body shape, ventral eyes and well developed spiracles of the the skate allows them to live benthically, buried in the sediment or using a longitudinal undulation of the pectoral fins known as Rajiform locomotion to glide along the water floor.[25] Current research suggests that some species of skates, in addition to their Rajiform locomotion, use their pelvic fins to perform ambulatory locomotion on the water floor.[26] This form of locomotion performed by the skate is being explored as a possible origin for our own development of walking by looking for similar neural pathways used for movement between skates and animals walking on land.[27]

Distribution and habitats[edit]

Skates are primarily found from the intertidal down to depths greater than 3,000 meters.[28] They are most commonly found along outer continental shelves and upper slopes.[29] They are typically more diverse at higher latitudes and in deep-water. In fact, skates are the only cartilaginous fish taxon to exhibit more diversity of species at higher latitudes. A cool, temperate to polar water in the deep sea can be a favorable environment for skates.[23] As the water becomes more shallow and warmer, skates are seen to be replaced by stingrays. Skates are absent from brackish and freshwater environments. However, there is a single estuarine species that has been found in Tasmania, Australia. Some skate fauna have been found inhabiting areas of rock cobble and high rocky relief.

Lifecycle[edit]

4 developing embryos located in an opened big skate egg case (mermaid's purse)

Reproduction[edit]

Skates mate at the same nursery ground each year. In order to fertilize the egg, males use claspers, a structure attached to the pelvic fins. The claspers allow them to direct the flow of semen into the female's cloaca. Skates are oviparous, meaning they lay eggs with very little development in the mother. This is one major difference from rays, which are viviparous, meaning they give birth to live young. When a female skate is fertilized, a protected case forms around the embryo called an egg case, or more commonly mermaid's purse. This egg case is then deposited out of the mothers body onto the ocean floor where the skates develop for up to 15 months before they enter the external environment.

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*Added to Chondrichthyes page.

Nervous System[edit]

Regions of a Chondrichthyes brain colored and labeled on dissected skate. The rostral end of the skate is to the right.

Chondrichthyes nervous system is composed of a small brain, 8-10 pairs of cranial nerves, and a spinal chord with spinal nerves[30]. They have several sensory organs which provide information to be processed. Ampullae of Lorenzini are a network of small jelly filled pores called electroreceptors which help the fish sense electric fields in water. This aids in finding prey, navigation, and sensing temperature. The Lateral line system has modified epithelial cells located externally which sense motion, vibration, and pressure in the water around them. Most subspecies have large well-developed eyes. Also, they have very powerful nostrils and olfactory organs. Their inner ears consist of 3 large semicircular canals which aid in balance and orientation. Their sound detecting apparatus has limited range and is typically more powerful at lower frequencies. Some subspecies have electric organs which can be used for defense and predation. They have relatively simple brains with the forebrain not greatly enlarged.

Reflection (Week 15)[edit]

Coming into this assignment, I didn’t really know what to expect. To be quite honest, it was a little overwhelming thinking about editing Wikipedia, especially because it was about a skate, which I didn’t even know existed before this project started. However, it was an extremely rewarding experience and it was fun to be able to work collaboratively to accomplish our goals.

My view of Wikipedia has changed a lot since starting the project. I’ve always been told that Wikipedia is not a refutable source and to stay away from it. I guess I typically am a rule follower so I didn’t use it too much. I learned two major things about it though through this project. The first being Wikipedia is usually a pretty reliable source. In all of the research I did, I never came across blatantly wrong information. I did however see a few instances of where information was either worded badly or incorrectly. This issue is not as big of an issue as wrong information, and is the reason people like us are important to Wikipedia. When people are viewing and editing Wikipedia often, it makes it more and more reliable. The other thing I learned is it is a great source for sources. All of the knowledge on Wikipedia is from unbiased refutable sources, and many times primary research. I had an assignment for another class on a biochemical disorder and almost every source I used, I got from the sources on Wikipedia. It is a great location for a hub of knowledge and information.

When approaching the assignment, the first thing we did was just read over the page. We talked at beginning stages about what we felt was not as good as it could be, and what was missing. We came up with a decent list that to start researching. As the semester went on, the project began to evolve. We learned more about the skate and were able to really know what was missing from the skate page. We started to add to our current information as well as add more. Another strategy we had was to check related pages. One thing we noticed was that there was no nervous system section on the Chondrichthyes page. We got this idea after the dissection of the skate brain went really well and we wanted to include an image of it. The dissection of our skate helped with the evolution of our project as well. It gave us a real understanding of what these systems looked like.

For our project, I wrote the mermaids purse section of skate specific characteristics, reproduction section of lifestyle, and the nervous system section on the Chondrichthyes page, as well as the images with those.  

Mermaids purse section of skate specific characteristics: The page before hand had briefly touched on this topic. I feel it was a good addition to the page, because it is one of the aspects that are very specific and identifiable in skates. The page after the addition was just more elaborated on the topic. I also moved an image from a different location in the article to it that fit better there.

Reproduction section of lifestyle: This section before my edit was decent, it just didn’t quite have as much information as we found necessary. I added a few sentences as well as linked a lot of terms. I also added an image of developing embryos in an egg case. I feel all this information helped to complete the section.

Nervous system section on the Chondrichthyes page: The Chondrichthyes page originally did not have this section at all. We felt it was a vital addition to this page, especially because it is a more popular page then skate. I added a bunch of links to important features. I also made an image with the brain regions of our dissected skate, which showed a typical chondrichthyes brain orientation.

This assignment went very smooth with my team. It was very easy to collaborate with them, and I never felt like I was contributing more than others on our product. Throughout the project, we were able to meet many times and work on our project. A lot of our collaboration was done person to person instead of through Wikipedia. We felt this was a more effective way to progress. Most of our ideas we added to the pages were thought of and mapped out together. We spent a lot of time trying to figure out how to structure our information together as well. We all edited all of the text for grammar throughout the process. Another thing I contributed is I helped Madi create the electric organ image that she wanted. While writing the reproduction section, Mckenna recommended to me an article that I ended up using to write a lot of the section. Overall, I felt very good about the collaboration of our group.

The only feedback from Wikipedia editors we received is we added a few pictures to a supplemental images section and a user deleted it. They stated that the images were not necessary to the page and covered in the passages. We talked about this issue together and decided that that was correct but figured out how to incorporate some of the images another way.

I thoroughly enjoyed this assignment. I even added to Wikipedia an image I made for a project in another class. One of the biggest differences in this project than normal class projects is the level of importance. On this assignment, if you do something wrong or bad, the repercussions are more than just getting a bad grade; it is spreading false information to the public. This being in the back of our mind forced us to be meticulous and perfect in the works that we produced. Editing Wikipedia is something I feel everyone who is an expert in a field should do. When you google nearly anything, the first page that pops up is Wikipedia. Since it is such a common source of knowledge, it is so important that it is reliable. The more people that add to it, and the more people that review it, will help broaden the easily accessible knowledge base available to everyone.

Comments from Dr. Schutz: (Week 5)[edit]

  1. Excellent start. You have identified some good gaps and found some potentially very good references that all look like primary literature (the gold standard).

Begin your work for next week by considering the following next steps:

  • How will you integrate each others edits? This may not be clear now and not always possible, but it should be attempted. You have already started to help each other out and are well on your way.
  • What kinds of images/illustrations will be useful for you to find (see info on appropriate use of images)/produce and contribute?
  • As you detail in your plan (very well done btw) many images can come directly from the dissections you will do, so think about how you want to approach that. Also, look ahead to week 11. The description for that assignment has numerous links to useful information for the appropriate use of images etc.
  • Start drafting some content as you prepare for next week.
  • Ask me in lab for your study animal so that you can make a plan for dissection.
  • Make sure all team members complete all training!
  • When asking for help (which is great) you will have better outcomes if you ask for specific feedback. Think about that when asking for a review or when posting in the talk pages...you have some great suggestions. I encourage you to post them.
  • It is clear to me who will focus on which sections, but you are going to want to establish a more formal organization to your page. I posted some sample sandboxes in the timeline for week two. Go back to those. I just suggest that you put names (real or wiki on the headings).
  • There is pretty much even contribution from all of you, great job.
  • watch out for some weird formatting around the "jump" form a link.
  • Just an idea, but you might want to consider dissecting the brain...and comparing it to our shark.

Osquaesitor (talk) 19:59, 12 March 2018 (UTC)

Sources[edit]

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  20. ^ Bustamante, Carlos; Lamilla, Julio; Concha, Francisco; Ebert, David A.; Bennett, Michael B. (2012-06-29). "Morphological Characters of the Thickbody Skate Amblyraja frerichsi (Krefft 1968) (Rajiformes: Rajidae), with Notes on Its Biology". PLOS ONE. 7 (6): e39963. doi:10.1371/journal.pone.0039963. ISSN 1932-6203.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  21. ^ Mabragaña, E.; Vazquez, D. M.; Gabbanelli, V.; Sabadin, D.; Barbini, S. A.; Lucifora, L. O. (2017-09-01). "Egg cases of the graytail skate Bathyraja griseocauda and the cuphead skate Bathyraja scaphiops from the south-west Atlantic Ocean". Journal of Fish Biology. 91 (3): 968–974. doi:10.1111/jfb.13380. ISSN 1095-8649.
  22. ^ Ebert, David; Davis, Chante (2007-01-18). Descriptions Of Skate Egg Cases (Chondrichthyes: Rajiformes: Rajoidei) From The Eastern North Pacific. Vol. 1393.
  23. ^ a b Macesic, Laura J.; Kajiura. "Electric organ morphology and function in the lesser electric ray, Narcine brasiliensis" (PDF). Zoology. 112: 442–450 – via ScienceDirect.
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  25. ^ Fins into limbs : evolution, development, and transformation. Hall, Brian K. (Brian Keith), 1941-. Chicago: University of Chicago Press. 2007. ISBN 9780226313405. OCLC 308649613.{{cite book}}: CS1 maint: others (link)
  26. ^ Lucifora, Luis O.; Vassallo, Aldo I. (2002-09-01). "Walking in skates (Chondrichthyes, Rajidae): anatomy, behaviour and analogies to tetrapod locomotion". Biological Journal of the Linnean Society. 77 (1): 35–41. doi:10.1046/j.1095-8312.2002.00085.x. ISSN 0024-4066.
  27. ^ Jung, Heekyung; Baek, Myungin; D’Elia, Kristen P.; Boisvert, Catherine; Currie, Peter D.; Tay, Boon-Hui; Venkatesh, Byrappa; Brown, Stuart M.; Heguy, Adriana (2018-02). "The Ancient Origins of Neural Substrates for Land Walking 3". Cell. 172 (4): 667–682.e15. doi:10.1016/j.cell.2018.01.013. PMC 5808577. PMID 29425489. {{cite journal}}: Check date values in: |date= (help)
  28. ^ Ebert, David A.; Compagno, Leonard J. V. (2007-10-01). "Biodiversity and systematics of skates (Chondrichthyes: Rajiformes: Rajoidei)". Environmental Biology of Fishes. 80 (2–3): 111–124. doi:10.1007/s10641-007-9247-0. ISSN 0378-1909.
  29. ^ Ebert, David A.; Bizzarro, Joseph J. (2007-10-01). "Standardized diet compositions and trophic levels of skates (Chondrichthyes: Rajiformes: Rajoidei)". Environmental Biology of Fishes. 80 (2–3): 221–237. doi:10.1007/s10641-007-9227-4. ISSN 0378-1909.
  30. ^ Collin, Shaun P. (2012). "The Neuroecology of Cartilaginous Fishes: Sensory Strategies for Survival". Brain, Behavior and Evolution. 80 (2): 80–96. doi:10.1159/000339870. ISSN 1421-9743.