User:Ahyneman/sandbox
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Analyzing Craniate Article
[edit]Is each fact referenced with an appropriate, reliable reference?
Most of the facts that are provided in the Wikipedia article have references, a few that do have sources have ones that need to be "verified" though. Other than that, most of the sources appear to be from textbooks of some sort which means they are reliable. However, the sources lack variety. It would you a good touch to add some journal articles or research in maybe.
Where does the information come from? Are these neutral sources? If biased, is that bias noted?
As mentioned above, most of the information from textbooks which are good, unbiased resources. However, it would be nice to to see some other unbiased resources added.
Are there viewpoints that are over-represented, or under-represented?
Pretty much everything on the page is under-represented. It is just mentioned briefly and then given a broad explanation.
Check a few citations. Do the links work? Is there any close paraphrasing or plagiarism in the article? Yes all the links work. There does not appear to be plagiarism. I used one of those anti-plagiarism sites who didn't thinks so either.
Is any information out of date? missing that could be added? Overall, this article is missing lots of details compared to other pages like the Tunicate page. It appears to have been put together in a rush and only brushes the the surface of what craniate are. For example, this page only covers the characteristics while other pages covers things like feeding cycles, body structures and goes more in-depth to classifications.
Dissection Proposal
[edit]- Proteidae
- Why? Growing up in the South, we spent a lot time as kids catching mudpuppes (we called them waterdogs) and I think it would be interesting to learn more about them in addition to dissecting the organism and working with it's internal structures.
- Proposed pages to edit:
- Chimaera
- Why? I would like to dissect the Chimaera because I enjoyed working with the shark in lab and according to the Wikipedia page, their closest living relatives are the sharks therefore I am more interested in this organism.
- Proposed pages to edit:
- Operculum (fish)
- Rhinochimaeridae
- The Chimaera page itself (link provided above)
- Columbidae / Pigeon (disambiguation)
- Why? My aunt raised pigeons so I have experience working with caring for them and would be interested in working with the organism in a different setting.
- Proposed pages to edit:
Week 5: Find Sources (03/05-03/11)
[edit]Pages to Edit:
- Egg case (Chondrichthyes) (Lead: Sophia)
- Possible Resources
- http://web.a.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=b57446c8-982e-4a78-8ebc-946aa818fdb1%40sessionmgr4006&vid=5&hid=4107
- Fischer, Jan, Martin Licht, Jürgen Kriwet, Jörg W. Schneider, Michael Buchwitz, and Peter Bartsch. "Egg capsule morphology provides new information about the interrelationships of chondrichthyan fishes." Journal of Systematic Palaeontology 12.3 (2013): 389-99. Web.
- “Egg capsule morphology provides new information about the interrelationships of chondrichthyan fishes”.
- Great simplistic diagrams comparing the morphology of many different types of egg cases. This information could be potentially helpful to the wiki page, however I am not confident this diagram would be able to be appropriately referenced.
- The article above compares the oviparity of various species, relating it to the evolutionary history of the chondrichthyan egg. Ten primary egg capsule morphotypes are compared with one another and explained in great detail, with accompanying diagrams. The information regarding the Chimaeridae egg capsule (and accompanying diagram) is of particular interest, as the wikipage for Egg Cases currently has only one sentance regarding the egg case produced by the chimaera. The fossil record, as well as the current phylogenetic tree, are also described and pictured within the document.
- http://web.a.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=b57446c8-982e-4a78-8ebc-946aa818fdb1%40sessionmgr4006&vid=7&hid=4107
- Mabragaña, E., D. E. Figueroa, L. B. Scenna, J. M. Díaz De Astarloa, J. H. Colonello, and G. Delpiani. "Chondrichthyan egg cases from the south-west Atlantic Ocean." Journal of Fish Biology 79.5 (2011): 1261-290. Web.
- “Chondrichthyan egg cases from the south-west Atlantic ocean”.
- Oviparity method compared between egg cases collected from 21 different chondrichthyan species--nice, simplistic egg case diagram included.
- http://web.a.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=b57446c8-982e-4a78-8ebc-946aa818fdb1%40sessionmgr4006&vid=19&hid=4107
- Reichert, Amber N., Lonny Lundsten, and David A. Ebert. "First North Pacific records of the pointy nosed blue chimaera, Hydrolagus cf. trolli (Chondrichthyes: Chimaeriformes: Chimaeridae)." Marine Biodiversity Records9.1 (2016): n. pag. Web.
- “First North Pacific records of pointy blue nosed chimera…”.
- General migratory sightings of (blue-nosed) chimaeras
- http://web.a.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=b57446c8-982e-4a78-8ebc-946aa818fdb1%40sessionmgr4006&vid=5&hid=4107
- Possible Resources
- Rabbit fish (Lead: Azana)
- Possible Resources:
- https://academic.oup.com/icesjms/article/70/6/1198/636894/Distribution-patterns-and-sexual-segregation-in
- Holt, R. E., Foggo, A., Neat, F. C., and Howell, K. L. "Distribution patterns and sexual segregation in chimaeras: implications for conservation and management." ICES Journal of Marine Science, 70: 1198–1205. Web. 09 Mar. 2017.
- "Distribution patterns and sexual segregation in chimaeras: implications for conservation and management."
- This journal article provides in-depth information about segregation that is related to sex and where each sex can be found.
- http://www.academia.edu/4055649/Preliminary_Age_and_Growth_Estimates_of_the_Rabbitfish_Chimaera_monstrosa_with_Implications_for_Future_Resource_Management
- Calis, E., Jackson, E. H., Nolan, C. P. and Jeal. "Preliminary Age and Growth Estimates of the Rabbitfish, Chimaera monstrosa, with Implications for Future Resource Management." Journal of Northwest Atlantic Fisheries 35 (2005). Web. 09 Mar. 2017.
- "Preliminary Age and Growth Estimates of the Rabbitfish, Chimaera monstrosa, with Implications for Future Resource Management."
- Provides information on dorsal spine related to growth in the rabbit fish. It has some good charts and figures that might be nice to add to the page as well
- MacPherson, E. "Food and feeding of Chimaera monstrosa, Linnaeus 1758, in the western Mediterranean." Journal du Conseil, 39(1980), 26-29.
- "Food and feeding of Chimaera monstrosa, Linnaeus 1758, in the western Mediterranean."
- This book provides information about the feeding habits of the rabbit fish, which is not a topic covered on the page yet.
- https://academic.oup.com/icesjms/article/70/6/1198/636894/Distribution-patterns-and-sexual-segregation-in
- Possible Resources:
- Venom (Lead: Chris)
- Possible resources for Venom wiki page:
- http://www.mdpi.com/2072-6651/7/5/1497/htm
- Rebekah Ziegman, and Paul Alewood. "Bioactive Components in Fish Venoms." MDPI. Multidisciplinary Digital Publishing Institute, 30 Apr. 2015. Web. 09 Mar. 2017.
- “Bioactive Components in Fish Venoms”
- The is a good cladogram showing all the venomous fish. There is also information on the possible medicinal properties of venom, which could be a good section to add the venom wiki page.
- http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8649.2009.02362.x/abstract
- Barnett, L. A. K., D. A. Ebert, and G. M. Cailliet. "Assessment of the Dorsal Fin Spine for Chimaeroid (Holocephali: Chimaeriformes) Age Estimation." Journal of Fish Biology. Blackwell Publishing Ltd, 09 Nov. 2009. Web. 09 Mar. 2017.
- “Assessment of the Dorsal Fin Spine for Chimaeroid Age Estimation”
- This article has some good information on the actual structure of the venomous spine in chimaera.
- http://onlinelibrary.wiley.com/doi/10.1111/j.1467-2979.2008.00309.x/abstract
- Sivan, Gisha. "Fish Venom: Pharmacological Features and Biological Significance." Fish and Fisheries. Blackwell Publishing Ltd, 06 Feb. 2009. Web. 09 Mar. 2017.
- "Fish venom: pharmacological features and biological significance"
- Could add on some information about the physiological effects of fish venom on the body
- http://www.mdpi.com/2072-6651/7/5/1497/htm
- Possible resources for Venom wiki page:
Week #6: Draft 1
[edit]Venom (Lead: Chris)
- What is the Systemic Source of Venom? After looking into a couple articles, it appears that chimaera my have a glandular epithelium that is located posterior to the dorsal spine. This could be a good potential anatomical structure to look further into for the chimaera. I have attached a link below to the article:
https://www.jstor.org/stable/1439692?seq=1#page_scan_tab_contents
- Other Related Taxa with Toxin Production.. Among the chondrites there are two subclasses, the Elasmobranchii and Holecephal (chimaera). The sharks and rays are among the Elasmobranchii are very closely related to the chimaera. There are certain species of rays that produce toxins. This may be an important clue into how the chimaera transfer their venom. It could also provide a totally novel mechanism to research further.
- Does Chimaera Produce Venom or Poison? Apparently a poison is any substance that causes irritation and must be touched, inhaled, or ingested. While venom is any poison that is delivered by a spine or injection like mechanism. Technically, since the chimaera uses a spine, it must be producing venom. Benson02 (talk) 04:25, 18 March 2017 (UTC)
Egg Case (Lead: Sophia)
- Source: Fischer, Jan, Martin Licht, Jürgen Kriwet, Jörg W. Schneider, Michael Buchwitz, and Peter Bartsch. "Egg capsule morphology provides new information about the interrelationships of chondrichthyan fishes." Journal of Systematic Palaeontology 12.3 (2013): 389-99. Web.
- Title of Article: “Egg capsule morphology provides new information about the interrelationships of chondrichthyan fishes”.
- General information: Great simplistic diagrams comparing the morphology of many different types of egg cases. This information could be potentially helpful to the wiki page, however I am not confident this diagram would be able to be appropriately referenced.
- ROUGH outline of discussion points: The article above compares the oviparity of various species, relating it to the evolutionary history of the chondrichthyan egg. Ten primary egg capsule morphotypes are compared with one another and explained in great detail, with accompanying diagrams. The information regarding the Chimaeridae egg capsule (and accompanying diagram) is of particular interest, as the wiki page for Egg Cases currently has only one sentence regarding the egg case produced by the chimaera. The fossil record, as well as the current phylogenetic tree, are also described and pictured within the document. Hansonsl (talk) 17:22, 20 March 2017 (UTC)
- Rabbit Fish (Lead: Azana)
- Title: "Food and feeding of Chimaera monstrosa, Linnaeus 1758, in the western Mediterranean"
- General Information: This article discusses the average diet of the Chimaera monstra. There are over thirty prey that are consumed by species, however their most prominent consumptions was a crabs which constituted for over 60 percent of their diet. This article provides a well laid out chart which shows the proportions of the various prey that are consumed.
- Although seasonal variations and changes in development do effect the diet of the Rabbit Fish, it is not dependent on differences in sex.
Week 7: Peer Review and Copy Edit (03/19-03/25)
[edit]Week 8: Spring Break (03/24-04/01)
[edit]Week 9: Respond to Peer Review (04/02-04/08)
[edit]Chris:
Group feedback themes: Some of the group feedback overlap included organization, narrowing focus, altering citations to wikipedia format and condensing topics. Response: I think we can consolidate drafts one and two (at lease I think this is what was meant by "merge sections"). I think this change would also clear up some organization issues as well. Also,I believe that we would all benefit by adding a specific written draft that would go on our chosen pages. In addition, I am going to change the citation to wikipedia format.
Personal feedback: The main feedback I saw was to maybe flesh out a more specific game plan and actually write out a draft. I plan on taking a couple pictures of the unique claspers on the Chimaera and post those to the wiki "claspers" page. Then I will make a hyperlink from the chimaera page to the claspers page. Finally, I am going to write a short summary of the unique features of the claspers on the chimaera page, with the hyperlink imbedded in the text. In addition to this I have done more research on the chimaera venom gland. I believe the gland may be a sacciform cell if it is indeed a unicellular gland. In response to the question posted by Murry4329, "are you going to compare the rabbit fish with other lineages?" Yes, I may compare the Chimaera, in reference to venom, because I found a great cladogram with venomous fishes. However, I believe there is still plenty to do on just the Chimaera first. That may be something else that could be researched later on if there is still time.Benson02 (talk) 01:01, 11 April 2017 (UTC)
Azana:
- You mention sex. Can you develop this further? Do you intend on looking at sexual dimorphism?
- I was intending to look at the sexual dimorphism and how that effects various processes such as growth, interactions between the two sexes and segregation.
- My first two resources are directed at this.
- After reading the feedback I received, I am considering switching from focusing on the processes to actually looking at physical characteristics or anatomical structures.
- Most of my feedback was directed toward me needing to pick an actual anatomical structure. I had a few in mind but was waiting to see if ours was going to be male or female. After seeing our team Chimaera and analyzing it up close, I was able to see that it has significantly sized pelvic claspers. I was considering picking this as my anatomical structure.
- I was intending to look at the sexual dimorphism and how that effects various processes such as growth, interactions between the two sexes and segregation.
- There was lot of confusion on why I included the feeding information. After looking at the page I realized that it did not include any information on feeding habits and thought that this would be a useful contribution to the page. However now I realize that it is probably to large of task to do both the sexual dimorphism and feeding.
- If I choose this topic to focus on instead of the pelvic claspers, I would probably use the jaws as my anatomical structure and do more research into what the anatomical structures are that are involved in feeding.
Sophia:
- There were parallel comments from reviewers encouraging the need for a diagram from resources I have found. I will continue moving forward with my plan to add said figure to the Egg Case page. Other parallel comments encouraged the further explanation of Chondrichthyan egg case morphology, and how it compares to other models.
- After reading the reviews, I realize that I hadn't previously written what I am envisioning for the Egg Case page. I will be working to craft a version of text I'd like to add to the Wikipedia page that explains, versus "tells" what I'd like to explain. The chondrichthyan egg case morphology will be the topic of my written addition to the page.
- I believe, and it seems that my reviewers agree, that there is strong enough content and resources gathered for me to write a strong addition to the Egg Case Wikipedia page. Therefore, despite my doubts (because the egg case is not actually observable during our Chimaera section in lab), I will continue to pursue a well-written addition to this particular page.
- As a team, after viewing the Chimaera in person, we were able to observe the large pelvic claspers. These would be an incredibly interesting and viable topic which is deserving of further research.
Week 10: Draft #2 (04/09-04/15)
[edit]Venom/Claspers (Chris)
[edit]The chimaera claspers are unique in that they are covered in tiny spine like projections. The many denticle protrusions face the anterior of the fish and are thought to aid in grasping onto to the female during mating[1]. When compared to its sister group, the elasmobrachii, the claspers of holocephali are much more exaggerated and are extremely large in proportion to its body. Also, they display either a bifurcate or trifurcate characteristics.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/11/Chimaera_Clasper.jpg/220px-Chimaera_Clasper.jpg)
- There are a couple changes/additions I might make next week. First, I would like to add a scale bar to the image as a point of reference. Second, I would like to make some actual physical measurements to the claspers and the body as a whole. Finally, it might be interesting to get a saggital plane view of the clasper and further explore the interior anatomy. All of this content will be added to the wiki clasper page.
- Unfortunately I haven't found much on venom gland during the direction. I am going to look further into next week and see what I can come up with.
Egg Case (Sophia)
[edit]…of the sea floor. Chimaeras (subclass Holocephali), some sharks, and skates are among the 43% of known Chondrichthian species to exhibit oviparity.[2] However, there are some key morphological differences that are specific to chimaeras. The spotted ratfish chimaera is also known as Hydrolagus colliei. There are currently 11 holocephalan fossil species that were found throughout the United States, Canada, Germany, and Russia.[2] The holocephalan egg capsule, or egg case, has a bulbous center flanked laterally by flattened collagen tissue. The flattened collagen tissue joins on the anterior end of the egg capsule to form a tail.[2]
Starting with the ellipses to potentially finish the sentence that is already posted on the Egg case (Chondrichthyes) wiki page.
Source primarily used:
Fischer, Jan, Martin Licht, Jürgen Kriwet, Jörg W. Schneider, Michael Buchwitz, and Peter Bartsch. "Egg capsule morphology provides new information about the interrelationships of chondrichthyan fishes." Journal of Systematic Palaeontology 12.3 (2013): 389-99. Web.
Spotted Ratfish Page Edit (Description- Jaws and Teeth, Diet) (Azana)
[edit]On Wikipedia page now: " It has a duckbill shaped snout and a rabbit-like face. The mouth is small and contains forward directed, incisor-shaped teeth, that act as plate-like grinding teeth."
- My Rough Edit: "...The mouth is small and contains one pair of forward directed, incisor-shaped teeth in the bottom jaw and two pairs in the top jaw. Unlike sharks who have sharp teeth that are easily replaceable, the spotted ratfish teeth are plate shaped, mineralized and permanent which assist them in grinding their prey.[3]"
- Huber, D.R., Dean, M.N., Summers, A. P. 2008. . Hard prey, soft jaws and the ontogeny of feeding mechanics in the spotted ratfish Hydrolagus collie. Journal of the Royal Society Interface 5 (25), 941-953.
- I want to mention in the diet section that they are known to be cannibals and feed on their egg cases and other chimaera, which I have seen on many reliable websites. However I have not found a source appropriate to use as a reference on the Wikipedia page yet. I am also still working on added some information about their jaws which I know are fused to their skull and have one the strongest bite forces which help them feed on the crunchy foods since they have soft jaws.
- I also want add a picuture of the teeth if I can find one since they are pretty unique.
Week #11: Begin Moving Work to Wikipedia (04/16-04/22)
[edit]Egg Case (Sophia)
[edit]Work added to Egg Case: Chondrichthyes page:
[edit]...of the sea floor. Chimaeras (subclass Holocephali), some sharks, and skates are among the 43% of known Chondrichthian species to exhibit oviparity. However, there are some key morphological differences that are specific to chimaeras. The spotted ratfish chimaera is also known as Hydrolagus colliei. There are currently 11 holocephalan fossil species that were found throughout the United States, Canada, Germany, and Russia. The holocephalan egg capsule, or egg case, has a bulbous center flanked laterally by flattened collagen tissue. The flattened collagen tissue joins on the anterior end of the egg capsule to form a tail.
Resource included in citation format:
Fischer, Jan, Martin Licht, Jürgen Kriwet, Jörg W. Schneider, Michael Buchwitz, and Peter Bartsch. "Egg capsule morphology provides new information about the interrelationships of chondrichthyan fishes." Journal of Systematic Palaeontology 12.3 (2013): 389-99. Web.
Venom/ Claspers (Chris)
[edit]Work added to Spotted ratfish page:
The male spotted ratfish possesses a cephalic clasper (tentaculum), which is a unique club-like organ not found in any other vertebrates.[4] The cephalic clasper is located on the head of the fish, just anterior to the eyes. The tip of the retractable organ is fleshy and lined with numerous small, sharp barbs. In order for the male to stay attached during courtship, the clasper has been observed to clamp down on the pectoral fin of the female.[5][6]
Edits continued on clasper but NOT added yet:
The chimaera claspers are unique to chimaeroid fishes because they are covered in tiny spine like projections. The many denticle-like protrusions face the anterior of the fish and are thought to aid in grasping the ventral side of the female during copulation. When compared to its sister group, the elasmobranchs, the claspers of holocephali are much more exaggerated and are extremely large in proportion to its body. Also, they display bifurcate characteristics on the interior of the clasper.
Jaws/Teeth (Azana)Work added to spotted ratfish page:
[edit]- The mouth is small and contains one pair of forward directed, incisor-shaped teeth in the bottom jaw and two pairs in the top jaw. Unlike sharks who have sharp teeth that are easily replaceable, the spotted ratfish teeth are plate shaped, mineralized and permanent which assist them in grinding their prey.
Continued edits for page:
- Like many bony fishes but unlike its sister group, the elasmobranchii, the upper jaw of the chimaera is fused with the skull. Although their jaws are soft and mouths are relatively small, they have the largest biting force and jaw leverage found within the holocephali which supports their ability to consume the prey that they do. [7][8]
- (Diet) In addition to the prey mentioned above, there is also evidence that ratfish exhibit cannibalism by eating other ratfish and egg cases.
Other citations:
Johnson A.G., Horton H.F. 1972 Length–weight relationship, food habits, parasites, and sex and age determination of the ratfish, Hydrolagus colliei (Lay and Bennett) Fish Bull. 70. p. 421–429.
Week #12: Continue improving your article (04/24-04/26)
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/11/Chimaera_Clasper.jpg/220px-Chimaera_Clasper.jpg)
Week #13: Continue Improving Article/ Illustrate Article (4/30-05/06)
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/e/ea/Spotted_Ratfish_Clasper.png/300px-Spotted_Ratfish_Clasper.png)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/16/Chimaera_Frontal_Tenaculum.jpg/220px-Chimaera_Frontal_Tenaculum.jpg)
Egg Case (Sophia)
[edit]Additions to wikipedia Egg Case:Chondrichthyes page:
[edit]I linked key words mentioned within my written portion about Chimaeras to their corresponding wikipedia pages. I also linked the term "egg cases" on the Nidamental Gland wikipedia page to the Egg Case disambiguation page offered by wikipedia.
I am looking into the nidamental glands as suggested, however after further reading, I believe these are only present in the Cephalopod class and not the Chondrichthyes class. Therefore, linking nidamental glands to the "Egg Case: Chondrichthyes" page may not be doable.
I will be conducting further research on the glands, especially considering the corresponding nidamental gland wikipedia page is offers limited information.
Illustrated Article Contributions:
[edit]To the Spotted ratfish page, I added an image depicting the cephalic clasper, also known as the frontal tenaculum.
Venom/Claspers (Chris)
[edit]Potential addition to Spotted ratfish page:
Male Spotted ratfish have a few secondary sexual characteristics, which include pared pelvic claspers, a single front tanaculum, and paired pelvic tentacula.[6] The pelvic claspers are located on the ventral side of the fish. They protrude out from the pelvic fins and are responsible for the movement of sperm to the oviducts of the female. [6] The interior of the pelvic clasper is supported by cartilage and separates into two branches, ultimately ending in a fleshing lobe on the posterior end.
Illustrated Article Contributions:
To the clasper page, I added an image depicting the clasper
**Hey Chris, I love what you did to the image in order to not only show a close up version of the clasper, but to give the reader context as well with a "zoomed out" picture of the posterior trunk of the animal. Very cool! I also like the three sentences above to be added to the Spotted ratfish page. I think the content, the way you have written it, is approachable and easy to understand in true wiki-fashion. May I just suggest, that instead of "...a few secondary sexual characteristics, which include..." that you try "...have multiple secondary sexual characteristics, of which include...". Also, the very end of the text stating "...ending in a fleshing lobe...", maybe should read "...ending in a fleshy lobe...".
**Hi Sophia, thank you for the thoughtful suggestions! I will definitely make the necessary adjustments. Benson02 (talk) 23:22, 12 May 2017 (UTC)
Week #14: Final Article (05/08-05/12)
[edit]Sophia
[edit]-Last week I added a photo of the frontal tenaculum onto the Spotted ratfish page. This week I will be "highlighting" the clasper structure itself as was suggested.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Highlighted_Frontal_Tenaculum_of_Spotted_ratfish_Chimaera.png/220px-Highlighted_Frontal_Tenaculum_of_Spotted_ratfish_Chimaera.png)
-Below I have added a proposed updated version of the image. Originally, I tried simply adding a boxed frame around the cephalic clasper, however I have yet to be successful. Let me know what you think!
-Another option I could try is formatting the frontal tenaculum photo similarly to how the ventral chimaera claspers are imaged now: I could add a second photo of only the frontal tenaculum in a text box and overlay it onto the original photo in order to highlight the structure in that way.
-Within the text The Biology of Sharks and Rays by A. Peter Klimley offers up some good information about Chimaera embryo development within the egg case while in utero and after extrusion. Below is a proposed draft of text to add to the Egg Case page.
Sharp projections located on the anterior and posterior end of the egg case serve to better secure the egg case in between rocks, as well as protection against potential predators.[5]
I also added a link from the Spotted ratfish page onto the Egg Case: Chondrichthyes page. There was already comprehensive information written about the childbirth process under the "Reproductive" subheading within the Spotted ratfish page, and I felt it would be redundant if I were to add that same information to the subheading titled "Chimaera" within the Egg Case page.
Chris
[edit]-Last week: I edited my initial high resolution clasper image and added a second "back ground" image to better help orient the viewer.
-This week: I have added the following to the Spotted ratfish (below). I felt the "reproduction" section could use more on the male sexual characteristics, so I added this short summary:
Male Spotted ratfish have multiple secondary sexual characteristics, which include paired pelvic claspers, a single frontal tenaculum, and paired pelvic tentacula.[6] The pelvic claspers are located on the ventral side of the fish. They protrude out from the pelvic fins and are responsible for the movement of sperm to the oviduct of the female. [6] The interior of the pelvic clasper is supported by cartilage and separates into two branches, ultimately ending in a fleshy lobe on the posterior end.
-This week: In addition, I made a few minor changes to my existing past edit and also added a few sentences to the end of the passage.
The cephalic clasper (tentaculum), possessed by the male fish, is a unique club-like organ not found in any other vertebrates.[4] The cephalic clasper is located on the head of the fish, just anterior to the eyes. The tip of the retractable organ is fleshy and lined with numerous small, sharp barbs. In order for the male to stay attached during courtship, the clasper has been observed to clamp down on the pectoral fin of the female.[5][6] Additional evidence for this type of usage has been found in the form of scars and scratches on the dorsal side of females. The significantly smaller body size of males, which is a sexually dimorphic characteristic, may be a contributing factor to this type of mating behavior.[5]
In regards to the "venom" content: Over the course of the dissection I never found any venomous glands, or tissue that may have produced venom. In addition, the cross-section of the "spine" did not yield any opening or hole that would suggest venom was released from that location. In light of this information, I did not end up adding any information to the venom page.
Azana
[edit]- Last week, I was going to add an image of the spotted ratfish skull or teeth, which ever I could get a better picture of. However, due to the process of stripping all of the muscles away I was unable to. this week I added an image that highlights the key features of the skull in the Chimaera species, not specifically the spotted ratfish. I was unable to find any other images within the time period that we are allowed to choose from. I also uploaded an image of the plated teeth from our dissection organism.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/8/87/Hydrolagus_colliei_teeth.jpg/220px-Hydrolagus_colliei_teeth.jpg)
- I want to add a more updated image of the skull and/or teeth if I am able to finish the skull prior to the end of the semester that way I can remove the older image. However, I am not sure if I will be able to do this.
- Through my search I never found much more on the cannibalistic nature the chimera so I didn't add it to the actual spotted ratfish page due to only having sources from like museum websites.
- Overall, I think I added everything that I intended to for the jaw and teeth. I don't think that there is much more that would be a valuable addition at this time except for better images.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Holocephali_skull_structures.png/220px-Holocephali_skull_structures.png)
- ^ Leigh-Sharpe, W. Harold. "The comparative morphology of the secondary sexual characters of holocephali and elasmobranch fishes. the claspers, clasper siphons, and clasper glands." Journal of Morphology 36.2 (1922): 199-220.
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