User:IreneIIS/sandbox

Article Evaluation

Shark anatomy

I am not sure if this how the citations on wikipedia work, but various citations, especially in the fin section, lead to other Wikipedia articles and not primary research papers. There are definite content gaps in the article, mainly in the internal organs section.

FINS

"Shark fins are supported by internal rays called ceratotrichia.”

• No citation

The whale shark citation did have several references like the IUCN and other research articles which is good.

I noticed that several of the citations in the article link to other wikipedia articles and has a very limited amount of citation to primary research articles

I think the article could include the development of structures for the shark

• Phylogeny tree
• The homologues of the 5 synapomorphies for the shark as a derived chordate.

TAIL

“Extreme”???- I think getting rid of exaggerated wording would help in keep the article neutral.

Dogfishshark citation has limited information- it leads to another wikipedia page that only has a few citations

It does well in mentioning the different tails that can be found in different shark species, the varying lobe sizes

TEETH

"Shark teeth are strong and made of enamel”

• Citation??

"Many sharks have 3 rows of teeth.”

• Citation???

INTERNAL ORGANS

Requires information about the spleen and the rectal glad

Information about the pancreas does not have a citation

Temperature

section can use more citations

The article is also missing information regarding reproduction as mentioned in the Talk page.

Although the history of the shark may seem irrelevant it can be useful to include how the different parts of the anatomy came to rise.

This article was part of a WikiProject.

Group Evaluation Questions

When reading through this article we noticed some content gaps where certain areas were left blank. Our question is what is the function of the shark's spleen and rectal gland? Where are these organs located and what do they look like? TBDoten (talk) 17:20, 25 February 2021 (UTC)TBDoten

When reading the article, I noticed the lack of primary literature, how can the use of primary literature help support the claims made in the article?~~~~

Group Discussion

We mainly discussed the importance of a source being bias, such as in blog posts, press releases, and company websites. These three sources will be able to write their own opinions and views on a certain topic and here on wikipedia we want to keep a neutral stance of the topics we choose to discuss. For a press release we did discuss that although the information that is being used may be true it is possible that the information is very one sided and is not giving both sides.

Plagiarism is when someones ideas are not given credit and a copyright violation is when something like a certain image is copied without permission.

To avoid close paraphrasing it would help to read the article until it is fulling understood and to take notes about the important points. When paraphrasing it will help to write using the notes from the article but without looking at the article to avoid accidental close paraphrasing.

Feedback: Discussion

• One thing I will remind you of is that plagiarism is more than not citing, it is also having too much similarity with the original work and this includes sentence structure.Osquaesitor (talk) 19:48, 12 March 2021 (UTC)

Spiny dogfish

Spiny dogfish#cite note-Animal-7

The spiny dogfish, spurdog, mud shark, or piked dogfish (Squalus acanthias) is one of the best known species of the Squalidae (dogfish) family of sharks, which is part of the Squaliformes order. While these common names may apply to several species, Squalus acanthias is distinguished by having two spines[citation needed] (one anterior to each dorsal fin) and lacks an anal fin. It is found mostly in shallow waters and further offshore in most parts of the world[citation needed], especially in temperate waters. Spiny dogfish in the northern Pacific Ocean have recently been reevaluated and found to constitute a separate species, now known as "Pacific spiny dogfish", Squalus suckleyi.

Feedback: Adding to an Article 1

• I am not sure if this is the edited original. I think it is your suggested edit.
• What about the "citation needed" part? Did you add that?
• Now that I am going to put you in groups, annotating your work and guiding your reader is key.
• One suggestion I have is that you copy and paste the original and then briefly describe what you are going to edit, then show those edits below.Osquaesitor (talk) 20:05, 12 March 2021 (UTC)

Description and behaviour[edit]

The spiny dogfish has dorsal fins, no anal fin, and white spots along its back. The caudal fin has asymmetrical lobes, forming a heterocercal tail. The species name acanthias refers to the shark's two spines. These are used defensively. If captured, the shark can arch its back to pierce its captor with spines near the dorsal fins that secrete a mild venom into its predator.

This shark is known to hunt in packs that can range up into the thousands. They are aggressive hunters and have a sizable diet that can range from squid, fish, crab, jellyfish, sea cucumber, shrimp and other invertebrates.

Males mature at around 11 years of age, growing to 80–100 cm (31–39 in) in length; females mature in 18–21 years and are slightly larger than males, reaching 98.5–159 cm (38.8–62.6 in). Both sexes are greyish brown in color and are countershaded. Males are identified by a pair of pelvic fins modified as sperm-transfer organs, or "claspers".[citation needed] The male inserts one clasper into the female cloaca during copulation. [citation needed]

Reproduction is aplacental viviparous, which was once called ovoviviparity. Fertilization is internal. The male inserts one clasper into the female oviduct orifice and injects sperm along a groove on the clasper's dorsal section. Immediately following fertilization, the eggs are surrounded by thin shells called "candles" with one candle usually surrounding several eggs. Mating takes place in the winter months with gestation lasting 22–24 months. Litters range between two and eleven, but average six or seven. [citations needed]

Spiny dogfish are bottom-dwellers. They are commonly found at depths of around 50–149 m (160–490 ft), but have been found deeper than 700 m (2,300 ft). [citations needed]

Life span estimates based on analysis of vertebral centra and annuli in the dorsal spines range from 35 to 54 years.

Commercial use[edit]

Braised dogfish Spiny dogfish are consumed as human food in Europe, the United States, Canada, New Zealand and Chile. The meat is primarily consumed in England, France, Italy, the Benelux countries, and Germany.[citation needed] The fins and tails are processed into fin needles and are used in less-expensive versions of shark fin soup in Chinese cuisine.^{[citation needed]} In England this and other dogfish are sold in fish-and-chip shops as "huss", and it was historically sold as "rock salmon" until the term was outlawed by consumer legislation. In France it is sold as "small salmon" (saumonette) and in Belgium and Germany it is sold as "sea eel" (zeepaling and Seeaal, respectively).[citation needed] It is also used as fertilizer, liver oil, and pet food. [citation needed]

-The liver oil from Spiny dogfish had served several purposes ranging from lamp, machine lubricant, and vitamin A, etc.

Because of its availability, cartilaginous skull, and manageable size, it is a popular vertebrate dissection specimen in both high schools and universities.[citation needed] Reported catches in 2000–2009 varied between 13,800 tonnes (in 2008) and 31,700 tonnes (in 2000).[10]- citation did not work

Bottom trawlers and sink gillnets are the primary equipment used to harvest spiny dogfish. In Mid-Atlantic and Southern New England fisheries, they are often caught when harvesting larger groundfish, classified as bycatch, and discarded. Recreational fishing accounts for an insignificant portion of the spiny dogfish harvest.

The Cape Cod Commercial Fishermen's Alliance has sponsored an initiative which promotes local, sustainably-caught use of the dogfish in restaurants and fish markets in the Cape Cod area of Massachusetts. The effort is funded by the National Oceanographic and Atmospheric Administration and attempts to get the public to consume under-utilized fish.

Conservation status and management[edit]

Once the most abundant shark species in the world, populations of Squalus acanthias have declined significantly. They are classified in the IUCN Red List of threatened species as Vulnerableglobally and Critically endangered in the Northeast Atlantic, meaning stocks around Europe have decreased by at least 95%. This is a direct result of overfishing to supply northern Europe's taste for rock salmon, saumonette, and zeepaling. Despite these alarming figures, very few management or conservation measures are in place for Squalus acanthias. In EU waters, a Total Allowable Catch (TAC) has been in place since 1999, but until 2007 it only applied to ICES Areas IIa and IV. It was also set well above the actual weight of fish being caught until 2005, rendering it meaningless. Since 2009 a maximum landing size of one metre (3 ft 3 in) has been imposed in order to protect the most valuable mature females. The TAC for 2011 was set at 0 tons, ending targeted fishing for the species in EU waters. It remains to be seen if populations will be able to recover.

In the recent past^[when?] the European market for spiny dogfish has increased dramatically, which led to the overfishing and decline of the species. This drastic increase led to the creation and implementation of many fishery management policies placing restrictions on the fishing of spiny dogfish. However, since the species is a late-maturing fish, it takes a while^[quantify] to rebuild the population.

In 2010, Greenpeace International added the spiny dogfish to its seafood red list. "The Greenpeace International seafood red list is a list of fish that are commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries." In the same year, the Convention on Migratory Species (CMS; also known as the Bonn Convention) listed the species (Northern Hemisphere populations) under Annex I of its Migratory Shark Memorandum of Understanding.

In recent years, however, the US has implemented fishing controls and opened up the fishery.^{[clarification needed]} The proposed quota for 2011 was 16.1 million kilograms (35.5 million lb) with a trip limit of 1,800 kg (4,000 lb), an increase over past years in which the quota has ranged from 2 to 9 million kilograms (5 to 20 million lb), with trip limits from 900 to 1,400 kg (2,000 to 3,000 lb). In 2010, NOAA announced the Eastern US Atlantic spiny dogfish stocks to be rebuilt, and in 2011, concerns about dogfish posing a serious predatory threat to other stocks resulted in an emergency amendment of the quota with nearly 6.8 million kilograms (15 million lb) being added.

In June 2018, the New Zealand Department of Conservation classified Squalus acanthias Linnaeus as "Not Threatened" with the qualifier "Secure Overseas" under the New Zealand Threat Classification System.

Feedback: Adding to an Article General Feedback

• My feedback above applies to all of the suggested edits you have here. In order to understand what you are doing, that requires me having your text open and the page itself side by side. This makes for difficult comparisons and it is hard for me or your colleagues (in the class or other Wikipedia editors) to help you. I think the suggestion I made above will be very useful here.
• I also think that organizing your work by WEEK and then by topic within week would have been a useful tool up to this point. See my advice sent to the class about checking out various other sandboxes for ideas.
• Ultimately, I think these sections that you point out are very good candidates for edits and I urge you to pick some of these as testing grounds for submissions to talk pages.
• A benefit of doing that is the potential feedback of other Wikipedians working on this page. They can help direct your potential edits and point you in useful directions.
• Remember to "sign" your work after submission. Even though this is your sandbox and you do not need to do it, get into the habit as it is an expectation of good faith practice when contributing to articles or talk pages.Osquaesitor (talk) 20:14, 12 March 2021 (UTC)

Fossil range[edit]

As a cartilaginous fish, shark tissues usually do not fossilize.

Squalus acanthias fossils date back to the Miocene 11 MYA.

Another group question we have is: What is the evolution of Sharks? The article could include a separate section providing information on the past ancestry of sharks, species that are closely related, and how their morphological and anatomical characteristics relate to past ancestors and other species. Knowl8dge (talk) 17:27, 25 February 2021 (UTC)

Proposed pages for editing

1.) Spiny dogfish

I would best be able to contribute to the description and behavior section. These sections could be separated and further elaborated upon.

- Squaliformes

- adding the phylogeny tree, and how ancestors have contributed to physical aspects of spiny dogfish

- aplacental viviparous

2.) Shark Anatomy

I would want to elaborate more on the sections that are already present like the skeleton section and the internal organ section

- Circulatory System

-spiracle

- Skin

3.) Lamprey

- check for plagiarism

- some websites do not exist, specifically in the fossil record section

- Hagfish, possibly elaborate on their close relationship

Week 6: 3/22-3/26

Draft 1 for Lamprey article

The internal anatomy of the lamprey contains various components. Some of these organs include a heart, brain, intestines, etc.

One of the key physical components to the lamprey are the intestines. The intestines are located ventral to the notochord. Intestines aid in osmoregulation and are also responsible for digestion. Intestines aid in osmoregulation by intaking water from its environment and desalinating the water they intake to an iso-osmotic state with respect to blood.

The buccal cavity, anterior to the gonads, are responsible to attaching, through suction, to either a stone or their prey. This then allows the tongue to be able to have contact with the stone to rasp algae or tear at the flesh or their prey to be able to drink their blood.

The heart of the lamprey is anterior to the intestines. It contains the sinus, one atrium, and one ventricle protected by the pericardial cartilages. Another organ the lamprey possesses is a brain. Their brain is divided into a forebrain, diencephalon, midbrain, cerebellum, and medulla.

The pineal gland of the lamprey is located in the midline of its body. For lampreys, the pineal eye is accompanied by the parapineal organ. The pineal gland is a photosensitive organ regulating melatonin production. This is done by capturing light signals through the photoreceptors cells converting them into intercellular signals. ~~~

PEER REVIEW WEEK 8- Cephalochordate

ABBY-

- you do a great job including other wikipedia articles into your paragraph. this is definitely something I need to contribute into my draft.

- I believe Asymmetron lucayanum need to be italicized

- the new edits a more concise and well cited

Noah

- Do you plan on continuing the morphology section?

- You did really well on citing your statements in your edits

- The intro paragraph is well written and well cited where needed.

- Since the intro section mentions the 5 synapomorphies it would be helpful to the page to discuss these more in depth in an additional section.

Katelyn

- I think the feeding section is written out really well.

- Feeding section needs citations

- also referencing other wikipedia articles could be helpful

Week 6: Drafting Edits[edit]

Abby's Edits to Cephalochordate[edit]

Old (Noah's Edit): A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly calledamphioxus or lancelets. Cephalochordates possess 5 synapomorphies, or primary characteristics, that all chordates have at some point during their larval or adulthood stages. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle, pharyngeal slits, and a post-anal tail (see chordate for descriptions of each). The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes and are commonly found in warm temperate and tropical seas worldwide.

New addition to Noah's edit: A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called amphioxus or lancelets. Cephalochordates possess 5 synapomorphies, or primary characteristics, that all chordates have at some point during their larval or adulthood stages. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle, pharyngeal slits, and a post-anal tail (see chordate for descriptions of each). The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes and are commonly found in warm temperate and tropical seas worldwide. With the presence of a notochord, adult amphioxus are able to swim and tolerate the tides of coastal environments, but they are most likely to be found within the sediment of these communities.

Old (2): Characteristics of Cephalochordata include that they are segmented marine animals that possess elongated bodies with a notochord that extends the length of the body, extending from head to tail, persisting throughout the animal's life. The members of this subphylum are very small and have no hard parts, making their fossils difficult to find. Fossilized species have been found in very old rocks predating vertebrates. There is a famous fossil shale from the Middle Cambrian, the Burgess Shale of British Columbia, which has yielded Pikaia fossils. Recently, a different cephalochordate fossil (Yunnanozoon) has been found in south China. It dates to the early Cambrian period, and is the earliest known fossil of the cephalochordate lineage. Members of this lineage have numerous gill slits, and have separate sexes.

New (2): Cephalochordates are segmented marine animals that possess elongated bodies containing a notochord that extends the length of the body from head to tail. They are only a few centimeters in length and due to their lack of a mineralized skeleton, their presence in the fossil record is minimal." There is a famous fossil shale from the Middle Cambrian, the Burgess Shale of British Columbia, which has yielded Pikaia fossils. Recently, a different cephalochordate fossil (Yunnanozoon) has been found in south China. It dates to the early Cambrian period, and is the earliest known fossil of the cephalochordate lineage.

Noah's edits to Cephalochordate[edit]

Morphology Section

• New/beginning: The general cephalochordate body plan is considered to be a dorsoventrally flipped version of earlier deuterostomes. Gene-expression studies on embryonic patterning suggest that body axis formation has inverted somewhere between hemichordates and chordates, where the ventral formation of body structures in earlier hemichordates is observed to be dorsal in cephalochordates.

Feeding Section[edit]

• Old: Cephalochordates employ a filter feeding system to consume microorganisms. The oral hood serves as the entrance for food particles, and possesses buccal cirri, which assist in sifting out larger food particles before they enter the buccal cavity. Epithelial cilia lining the mouth and pharynx form a specialized "wheel organ" situated at the dorsal and posterior end of the cavity. The motion of the cilia resembles the motion of a turning wheel, hence the organ's name, and transports the captured food particles. Behind this organ is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before being brought to the epibranchial groove on the dorsal side of the pharynx.Following this, the food is transferred to the gut, and excess water is pumped from the pharynx through the pharyngeal slits. This excess water passes through the atriopore and is then excreted from the body.
• New: "The oral hood serves as the entrance for incoming food particles. Buccal cirri, projections that originate from the free edge of the oral hood, assist in sifting out larger food particles before they enter the buccal cavity. Epithelial cilia lining the inside walls of the oral hood then bring the food particles into the mouth. The coordinated movement of several ciliated tracts helps facilitate food ingestion through a rotating motion that is similar to that of a wheel, causes cilia to be referred to as “wheel organ”. One of these ciliated tracts located on the oral hood forms a ciliated cavity, called Hatschek's pit, which aids in food collection by secreting mucous into the buccal cavity to capture food particles. Located behind the buccal cirri is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before being brought to the epibranchial groove on the dorsal side of the pharynx. Food particles are then transferred to the gut and excess water is pumped out of the pharynx through the pharyngeal slits. Excess water passes through the single atriopore as it is excreted from the body."

Intro Paragraph[edit]

• Old: A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called amphioxus or lancelets. Cephalochordates are chordates with all 5 synapomorphies, the characteristics all chordates have during the larval or adulthood stages. These synapomorphies include: notochord, dorsal hollow nerve cord, endostyle, pharynx and post-anal tail. The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum.Cephalochordates are represented in modern oceans by the Amphioxiformes.
• New: A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called amphioxus or lancelets. Cephalochordates possess 5 synapomorphies, or primary characteristics, that all chordates have at some point during their larval or adulthood stages. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle, pharyngeal slits, and a post-anal tail (see chordate for descriptions of each). The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes and are commonly found in warm temperate and tropical seas worldwide.NoahMcGoff (talk) 02:10, 24 March 2021 (UTC)

Noah's edits to Chordate[edit]

Intro paragraph[edit]

• Old: A chordate (/ˈkɔːrdeɪt/) is an animal of the phylum Chordata (/kɔːrˈdeɪtə/). During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, and a post-anal tail: these four anatomical features define this phylum. Chordates are also bilaterally symmetric, and have a coelom, metameric segmentation, and circulatory system.
• New: A chordate (/ˈkɔːrdeɪt/) is an animal of the phylum Chordata (/kɔːrˈdeɪtə/). All chordates possess 5 synapomorphies, or primary characteristics, at some point during their larval or adulthood stages that distinguish them from all other taxa. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle or thyroid, pharyngeal slits, and a post-anal tail. Chordates get their name from their characteristic “notochord”, which plays a significant role in chordate structure and movement. Chordates are also bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit metameric segmentation.NoahMcGoff (talk) 02:10, 24 March 2021 (UTC)

Katelyn's edits to Cephalochordate[edit]

• Morphological Section
  • Noah's New/beginning Morphological Section: The general cephalochordate body plan is considered to be a dorsoventrally flipped version of earlier deuterostomes. Gene-expression studies on embryonic patterning suggest that body axis formation has inverted somewhere between hemichordates and chordates, where the ventral formation of body structures in earlier hemichordates is observed to be dorsal in cephalochordates.
  • My additions including muscles: Studies have shown that there is a correlation between the branchiomeric muscles of vertebrates with the orobranchial muscles within the pharynx of chordates. These orobranchial muscles begin to develop in the early larval stages of the cephalochordates. The muscles eventually form into the adult hood during metaphorphsis. (I will add on more later, I just need to fully understand and research more.)
• Feeding Section
  • Noah's new edits: "The oral hood serves as the entrance for incoming food particles. Buccal cirri, projections that originate from the free edge of the oral hood, assist in sifting out larger food particles before they enter the buccal cavity. Epithelial cilia lining the inside walls of the oral hood then bring the food particles into the mouth. The coordinated movement of several ciliated tracts helps facilitate food ingestion through a rotating motion that is similar to that of a wheel, causes cilia to be referred to as “wheel organ”. One of these ciliated tracts located on the oral hood forms a ciliated cavity, called Hatschek's pit, which aids in food collection by secreting mucous into the buccal cavity to capture food particles. Located behind the buccal cirri is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before being brought to the epibranchial groove on the dorsal side of the pharynx. Food particles are then transferred to the gut and excess water is pumped out of the pharynx through the pharyngeal slits. Excess water passes through the single atriopore as it is excreted from the body."
  • My changes/additions: Cephalochordates have developed a filter feeding system, called the oral hood, that serves as the entrance for incoming food particles. The free edge of the oral hood contains Buccal cirri, small filament-like projections, that assist in sifting out larger food particles before they enter the buccal cavity. These projections are chemoreceptors that stimulate the epithelial cilia lining inside the walls of the oral hood to bring food particles into the mouth. The coordinated movement of several ciliated tracts helps facilitate food ingestion through a rotating motion that is similar to that of a wheel, causing cilia to be referred to as “wheel organ”. One of these ciliated tracts located on the oral hood forms a ciliated cavity, called Hatschek's pit, which aids in food collection by secreting mucous into the buccal cavity to capture food particles. Located behind the buccal cirri is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before transferring to the epibranchial groove on the dorsal side of the pharynx. Food particles are then transported to the gut while excess water is pumped out of the pharynx through the pharyngeal slits. The excess water will exit the atrium using the single atriopore as it is excretes from the body."

Peer review for - shark anatomists

Alyssa J.

- You did really well in citing sources for your different statements

- adding a citation to the first sentence of the skin section

- I do agree that the skin section should be made a sub-heading under the integument section

- your draft has a clear structure of what you are planning to rearrange and add to the page

Taylor S.

- Your draft is very easy to follow. I was just wondering where in the article this would be added to.

- I'm not sure if the first sentence would be appropriate. The synapomorphies didn't necessary evolve for the sharks, so possibly changing the wording could be helpful

Alexia

- Your section was very interesting to read!

- not very neutral in the first sentence

- reliable resources

- do you plan to add previous work from the teeth section to your work?

Week 6: Draft 1 - Alyssa Jordan[edit]

• Possible rearrangement and addition of information:
  • In the Shark anatomy page, they have sections on "Skin" and "Integument," but what should really be changed about this is that the Integument section should be it's own heading, with "Skin" as a subheading because skin is a component of integument. Also, the Ampullae of Lorenzini page could be used to create another subsection under integument that is referenced.
  • Here is the possible rearrangement and addition for the new section:

Integument[edit]

Main article: Dermal denticle

Unlike bony fish, the sharks have a complex dermal corset made of flexible collagenous fibres and arranged as a helical network surrounding their body. This works as an outer skeleton, providing attachment for their swimming muscles and thus saving energy. A similar arrangement of collagen fibres has been discovered in dolphins and squid. Their dermal teeth give them hydrodynamic advantages as they reduce turbulence while swimming.

Skin[edit]

Unlike other fish, sharks do not have scales, but rather denticles. Denticles are made of layers of dentine and a surface of enamel, they are V-shaped. Riblets are sockets in the shark's skin which hold the denticles. These denticles on the skin allow for the shark to move almost effortlessly, move faster, and move quietly. The skin of sharks is similar to the feeling of sandpaper, rough and abrasive.

Ampullae of Lorenzini[edit]

Being most prevalent in cartilaginous fish, fish have a series of sensory organs that are arranged as a network of hundreds to thousands of pores filled with jelly near their eyes, ears, mouth, and nose. These electroreceptors are called ampullae of Lorenzini and in 1678 they were first discovered by an Italian physician and ichthyologist, Stefano Lorenzini. These pores are used to sense and detect electromagnetic fields, and often times these aid in navigational skills and hunting down prey. This can be particularly important at night, because sharks can't just depend on their vision in dark settings, they need another mechanism to help them navigate. Specifically, they are able to detect prey that is buried beneath the sand. There are two different forms of electrolocation, passive electrolocation and active electrolocation, and sharks rely heavily on these for navigation.

Placoid Scales[edit]

Main article: Fish scale

Rough and rigid placoid scales (dermal denticles) coat the skin of sharks, rays and cartilaginous fishes. Homologous in structure to the teeth of vertebrates, these extremely strong scales serve the function of reducing turbulence and drag in water as they are reduce high velocity flow. The larger the fish, the more placoid scales they are likely to have. These projections are extremely teeth-like.

Muscles[edit]

Viewed as pelagic predators, sharks have a constantly elevated body temperature through their continuity in swimming, ultimately posing as a physiological advantage for sharks. A large reason they possess this advantage is due to the fact that they possess a red, aerobic, locomotor muscle (RM) and a white locomotor muscle (WM). Temperature largely affects the ability for muscles to contract, and this is with respect to both the environment and internal organismal temperature.

Red Locomotor Muscle[edit]

Producing approximately 25-50% of a shark's power, the RM is what powers the continuous swimming of sharks. This muscle thrives in elevated temperatures and is seen as almost mammal-like. The optimal temperature range for function is 20 to 30 degrees Celsius, and the muscles are deemed ineffective if exposed to cooler temperatures. Overall, the temperature of the RM is retained metabolically and is greatly above that of the external water temperature. This muscles also receives a sufficient blood supply which is why sharks can swim for extended periods of time, which helps break down fat. This muscle is concentrated in the ventral region of the shark, and is next to the vertebral column ultimately making the spinal column stronger. In other words, the first dorsal fin is posterior to the RM. In other fishes, the RM is more lateral. This muscle is increasingly thermally sensitive in both salmon shark and tuna.

White Locomotor Muscle[edit]

The WM in sharks is not as thermally dependent, therefore it is more optimal in functioning across various temperatures. The help power short bursts in a shark's swimming. This muscle is in close proximity to the RM, ultimately allowing for heat transfer from the RM to the WM. Although more suitable for cold temperatures, there has been considerable benefit from its proximal location the RM, only increasing its function. This muscle is really important in tail locomotion, and is responsible for the pulsating of a sharks tail and propelling the shark forward. The muscle contracts, and then stiffens to allow the shark to coast through the water.

The Five Synapomorphies - Taylor Stokes[edit]

The Five Cephalochordate Synapomorphies[edit]

The chondricthyes 5 synapomorphies, otherwise known as sharks, evolved from the cephalochordates. The five synapomorphies are pharyngeal slit, dorsal nerve cord, notochord, Endostyle, and the post-anal-tail. In cephalochordates, the  pharyngeal slit, or pharynx, are lateral to the throat of the chordate and work as filters by letting water pass over this region in order to retain nutrients and oxygen from gas exchange occurring. The dorsal nerve cord serves as a hollow-like backbone where signals are sent throughout the body due to nervous tissue being located in this region. The notochord is also toward the back of the chordate but closer toward the middle of the body than the dorsal nerve cord and is a water-filled structure that allows the chordate to move in water. Endostyle is underneath the pharyngeal gill slits where proteins give the chordate energy and sustenance. Lastly, the post-anal-tail is muscular and allows the chordate to move in water.

The Five Derived Synapomorphies in Sharks[edit]

These chordate synapomorphies changed and developed into characteristics that were more desirable traits for sharks' needs. These evolved synapomorphies are crucial for the current sharks lifestyle, for example, the pharyngeal slit changed to form into become a jaw and gills. The dorsal nerve cord still sends signals to the body but in a more organized fashion, namely using the central nervous system. The notochord changed from allowing movement in water to discs being formed in between vertebrae allowing for protection and acting as a buffer when movement occurs. The Endostyle changed to adapt to the sharks metabolism to become faster and allow for the thyroid hormone to become present. The post-anal-tail helps the shark move in water but also helps with balance too. An article that provided good incite for this topic was in homology review of cephalochordates and in Figure 1 and 2 it discussed gill slits and had good depictions of the cephalochordate in the larva stage.

Shark Internal Organs[edit]

The shark internal organs are fascinating and serve as having important functions for the shark. It was found on the Shark page that sharks reproductive organs serve to reproduce sexually where the male delivers sperm to the female using claspers that insert into the females oviduct. This then allows the female to give birth to live young, although some do lay eggs. The shark anatomy page describes the shark stomach but doesn't touch base on how buoyancy is established from air taking up space and providing sharks the ability to float as described in the sharkpage. The stomach also has shorter intestines than most animals, also discussed on the shark page, which causes food to take greater amounts of time to fully digest before excreted from the body. At the very end of the short intestine lies the rectal gland which is important for the excretion waste from the animal. The shark liver is also discussed on the shark page and shark anatomypage where it is full of an oily-like substance called shark liver oil that helps the sharks be more buoyant and acts as an energy storer where it can be utilized when needed. The sharks liver also helps with filtrating the blood and waste while also acting as a storage region for vitamins which is incredibly important especially if the shark goes a long time without eating or if the shark has extreme amounts of urea within the system, the liver helps with both of these scenarios. Sharks also have osmoregulation which allows the shark to have high concentrations and amounts of urea which allows them to not become dehydrated from living in seawater as opposed to freshwater. The shark kidney excretes the urea that is needed for the shark to have in its system to not become dehydrated from living in seawater. Sharks hearts have two chambers and the way the heart pumps is described on the shark page. The shark hearts main importance though is providing oxygenated blood to the entire body while filtering out the deoxygenated blood. A good media picture is depicted in the this shark anatomy Shark Anatomy (50693674756) photo where it shows the beginning half of the shark, especially the gills. Shark gills were derived from the synapomorphy pharyngeal gill slits and are essential for them to breathe underwater and the process to breathe is described in the shark page. A sharks spleen is also incredibly important because it is where red blood cells (RBC's) are derived and is also where the immune system functions to fight off pathogens. The pancreas of the shark helps with digestion by producing the enzymes needed to break down the large chunks of food most sharks bite out of and the pancreas serves to help keep the metabolism at a fast pace to accommodate for the large amounts of food taken in.   

Shark teeth - Alexia Sioda[edit]

Main Article: Shark tooth

A shark tooth is one of the numerous teeth of a shark. Shark teeth are a very fascinating study subject because they are highly mineralized tissues that are continually being produced by sharks. Sharks have a constant shedding of their teeth and for example, Carcharhiniformes shed approximately 35,000 teeth in a lifetime, replacing those that fall out. Several studies suggest that sharks are able to replace their teeth once a week because they grow in the gum tissue unlike most vertebrates that grow their teeth in alveoli. They are only shed once new teeth are formed underneath and push them out of the connective tissue that was holding them in place. There are four basic types of shark teeth: dense flattened, needle-like, pointed lower with triangular upper, and non-functional. The type of tooth that a shark has depends on its diet and feeding habits.

Fossilized evidence of teeth have dated back to almost 450 million years ago indicating the most ancient types of sharks occurred during the Late Ordovician period.

The sex of the shark also plays a role in the development of teeth and the differences in teeth in species due to gender is called sexual heterodonty.Usually, females have larger teeth because on average they are usually larger than males. Also, age can change the shape of teeth in which "juvenile teeth start out more narrow ad robust, while adult teeth are broader and thinner".

WEEK 9: 4/12-4/16

The internal anatomy of the lamprey contains various components. Some of these organs include a heart, brain, intestines.

One of the key physical components to the lamprey are the intestines. The intestines are located ventral to the notochord. Intestines aid in osmoregulation by intaking water from its environment and desalinating the water they intake to an iso-osmotic state with respect to blood.

The buccal cavity, anterior to the gonads, are responsible to attaching, through suction, to either a stone or their prey. This then allows the tongue to be able to have contact with the stone to rasp algae or tear at the flesh or their prey to be able to drink their blood, and are also responsible for digestion.

The heart of the lamprey is anterior to the intestines. It contains the sinus, one atrium, and one ventricle protected by the pericardial cartilages. Another organ the lamprey possesses is a brain. Their brain is divided into a forebrain, diencephalon, midbrain, cerebellum, and medulla.

The pineal gland of the lamprey is located in the midline of its body. For lampreys, the pineal eye is accompanied by the parapineal organ. The pineal gland is a photosensitive organ regulating melatonin production. This is done by capturing light signals through the photoreceptors cells converting them into intercellular signals.

What I plan to edit:

- edit wording of sentences to make sentences flow better and be more concise

- add additional links to text, wiki link, adding wikipedia articles to certain words in sentences

Edited draft

The internal anatomy of the lamprey contains various components. Some of these organs include a heart, brain, and intestines.

One of the key physical components to the lamprey are the intestines, which are located ventral to the notochord. Intestines aid in osmoregulation by intaking water from its environment and desalinating the water they intake to an iso-osmotic state with respect to blood, and are also responsible for digestion.

The buccal cavity, anterior to the gonads, are responsible to attaching, through suction, to either a stone or their prey. This then allows the tongue to be able to have contact with the stone to rasp algae or tear at the flesh of their prey to be able to drink their blood. The heart of the lamprey is anterior to the intestines. It contains the sinus, one atrium, and one ventricle protected by the pericardial cartilages.

The brain is divided into a forebrain, diencephalon, midbrain, cerebellum, and medulla.

The pineal gland, a photosensitive organ regulating melatonin production by capturing light signals through the photoreceptor cell converting them into intercellular signals, of the lamprey is located in the midline of its body. For lampreys, the pineal eye is accompanied by the parapineal organ.

Week 11 second draft

The internal anatomy of the lamprey contains various components. Some of these organs include a heart, brain, and intestines.

One of the key physical components to the lamprey are the intestines, which are located ventral to the notochord. Intestines aid in osmoregulation by intaking water from its environment and desalinating the water they intake to an iso-osmotic state with respect to blood, and are also responsible for digestion.

The buccal cavity, anterior to the gonads, are responsible to attaching, through suction, to either a stone or their prey. This then allows the tongue to be able to have contact with the stone to rasp algae or tear at the flesh of their prey to be able to drink their blood.

The heart of the lamprey is anterior to the intestines. It contains the sinus, one atrium, and one ventricle protected by the pericardial cartilages.

The brain is divided into a forebrain, diencephalon, midbrain, cerebellum, and medulla.

The pineal gland, a photosensitive organ regulating melatonin production by capturing light signals through the photoreceptor cell converting them into intercellular signals, of the lamprey is located in the midline of its body. For lampreys, the pineal eye is accompanied by the parapineal organ.

Final Draft for Lamprey Article

Lateral cross-section of Lamprey demonstrating internal anatomy.

The internal anatomy of the lamprey contains various components. Some of these organs include a heart, brain, and intestines.

One of the key physical components to the lamprey are the intestines, which are located ventral to the notochord. Intestines aid in osmoregulation by intaking water from its environment and desalinating the water they intake to an iso-osmotic state with respect to blood, and are also responsible for digestion.

The buccal cavity, anterior to the gonads, are responsible to attaching, through suction, to either a stone or their prey. This then allows the tongue to be able to have contact with the stone to rasp algae or tear at the flesh of their prey to be able to drink their blood.

The heart of the lamprey is anterior to the intestines. It contains the sinus, one atrium, and one ventricle protected by the pericardial cartilages.

The brain is divided into the forebrain, diencephalon, midbrain, cerebellum, and medulla.

The pineal gland, a photosensitive organ regulating melatonin production by capturing light signals through the photoreceptor cell concerting them into intercellular signals, of the lamprey is located in the midline of its body, for lamprey, the pineal eye is accompanied by the parapineal organ.