Dogfish Shark Dissection Lab
Preparation for Lab & Learning the Anatomy
Before any actions may ensue, the correct tools must be collected. It is important to have the following: scalpel, dissection scissors, tweezers, latex gloves, forceps, teaser needles (angled and straight), and a tub large enough to hold the full length of the shark. In order to start the examination and observation, the first step before dissection, the bag containing the dogfish specimen must first be cut open and drained of the formaldehyde used to preserve the shark. Place the shark in the tub to examine the anatomy and make observations of the exterior of the shark. Always get a good feel of the animal before dissection. Next is the total measurement of the shark, it’s essential that it be measured in centimeters. Dogfish are an average of 70-100cm, the dogfish used in the lab was approximately 87 centimeters in length. The last step of preparation is to take a skin graft. It should be a section no larger than 2 square inches. Make sure to only trim the skin, and it should be cut at the thickest part of
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Using a scalpel, make an incision from the pectoral girdle all the way to the cloacal opening. You may use tweezers to hold the skin back while you make the cut. Now observe what can be seen of the inside by making this cut. The livers were the first prominent features that were noticed, as it is the largest organ in the body cavity and quite easy to see. Grab the livers and feel the texture. They are smooth and rather squishy to the touch. The liver is rich in oil which stores energy for the shark. (Brown, 2011) These oils cause it to feel supple, squishy, and smooth like observed earlier. The shark used in the lab was a female, and pregnant. An incision was made in the ovary to reveal the young. However, the offspring were not in at an advanced enough stage and appeared immature, like the image on the right-hand
The film Sharkwater is a documentary directed and produced by Rob Stewart. Rob is an underwater photographer and a biologist that has a fascination with sharks, and their behavioral aspects. His way of studying these creatures he is able to learn about life and how to survive on this earth. This film showed the characteristics of reflexive documentary, this is because of the attention drawn into the sharks, their behaviors, and how we are affecting them. A statement that really stuck the documentary is people are taught their whole entire lives that sharks are dangerous but when you finally see it underwater your whole life can change in a flash. Rob made a very valid point as well, which is believed to be his thesis statement.
Gabriel Fallopius was one of the most noteworthy and respected Italian anatomists of the sixteenth century. He was known for many things during his lifetime. Although, to this day, he is well known for many of the great discoveries he encountered. During his lifetime in the 16th century, many people didn’t know much about the inside of today’s reproductive system, how they looked like, or what they were. Gabriel Fallopius inspired so many of his students to continue researching in the medical field who later became famous medical professionals.
Once the external anatomy was observed the pig was then laid down on the dissection pan and held down by rubber bands exposing the ventral side of the pig. Then the cardiovascular and digestive systems were analyzed. The fetal pig did in fact have small teeth which were fairly sharp. Before the lab I wasn’t aware of the intricate details of the mouth cavity or that the kidneys were underneath the intestines. The hardest part was locating the trachea and the gall bladder. Additionally actually feeling the heart and various parts of the fetal pigs internal anatomy made learning the parts of the body
The Carcharhinus leucas commonly called the "bull shark" is a very unique shark. The bull shark can live in both salt water and fresh water but is commonly found along the Mississippi River and around Nicaragua. The bull sharks has a very blunt rounded nose giving it a bullish type of appearance thus giving it the name bull shark. The sharks are a dark black to a light grey with a white underbelly. Bull sharks can grow to be about 350 cm long and weigh around 230 kilograms. Bull sharks also tend to have smaller eyes compared to many other sharks which indicates that the bull sharks have limited vision. The bull sharks have triangular teeth like the great white shark (one of the bull sharks cousins). The bulls teeth are heavily serrated and are about 1.5 inches long which makes it easy to tear apart the flesh of their prey.
The experimenters noticed the mink was a male. The dissection began with an posterior I-Cut stemming from the shoulders, down the abdomen to the hips. A scalpel was used lightly to open the abdominal skin, however not cutting too deep to where the abdominal wall was opened. The skin was stiff near the abdominal area, thin on the arms, and thicker around the legs. After the skin was peeled back with forceps and scalpel, the muscle was exposed. The experimenters located ten muscles by using a probe to make the certain muscle located more visible. The first muscle found was the sternomastoid located in the center of the neck, following was the biceps brachii which was located in the shoulders, the pectoralis muscle was located in the mid-chest area, the sartorius was located in the top thigh area in the middle from hip region to the knee, the tibialis anterior was located right on the tibia bone. Next muscle was the triceps brachii, which was three muscles, located in the upper arm area. The masseter muscle was located on the head in between the ear canal and the jaw, the rectus abdominis was located posterior abdominal area, the gastrocnemius was located on the calf of the legs, and the last muscle located was the rectus femoris was on the upper thigh region on the femur
By the beginning of the 18th century, the theory of preformation was widely accepted and had become the dominant model of embryonic development. The research indicated, “This time period saw the beginning of the concept of emboîtement, meaning encasement: the idea that each offspring is contained pre-formed within the gonads of its parents” (Lawrence 2013). Nicolas Malebranche contributed to this theory and the model by creating a fully reasoned explanation of it based on the Cartesian principles of mechanism. Therefore, he was the first to declare that every life that would exist on earth was created at the moment of creation and that future members of each species were present in the ovary of the female. For example, this idea is often compared to the metaphor of the Russian nesting dolls with an infinite number of smaller dolls inside. During this period of time the ovist model of preformation, it was assumed that the seminal fluid from the male parent was only required to begin the process of growth in the preformed embryo. However, this theory was challenged by scientists that w...
“Second, eggs are retrieved through a minor surgical procedure that uses ultrasound imaging to guide a hollow needle through the pelvic cavity to
Information (sub-point): Shark finning affects the shark most clearly on an individualistic scale. The removal of the shark’s fins makes it nearly impossible for the shark to swim once it is dumped back into the ocean. According to author William J Bennetta, many species of sharks, known as “obligate ram ventilators”, lack the ability to pump water through their gills if they are not constantly moving, and “presumably asphyxiate if unable to move” (Bennetta, 1996). Along with all the cuts, gashes, and beatings that come along with shark finning, most sharks that undergo finning die a very long and painful death due to loss of blood and suffocation.
... numerous herbal ingredients which are beneficial to human health; still, it is not directly because of on shark fins.
Although scientific fiction movies are heavily criticized for being extremely exaggerated and containing little scientific value, sci-fi movies can be used as decent educational tools because they enabling viewers to discern fact from fiction within the film. This can especially be seen in the film Sharknado, which is based on dramatic and over-exaggerated scientific principles. Although the film consists of numerous occasions that are based on poor science, the lack of credibility within the film is especially seen in the concept and presence of a “sharknado,” the anatomy and behavior of the sharks, and the characters’ triumphant defeat of the “sharknado” at the finale of the film. The first example of poor science within the film can be found in the concept of the “sharknado.” This concept is initially
caused by a blunder in the process of cell division during the formation of the reproductive cells
On average they weigh 4,000-7,000 pounds and grow approximately 16-20 feet long ( Great white sharks 1). < commentary needed>Great Whites are the apex predator of the ocean containing 300 serrated teeth and highly-developed senses to hunt prey. Sharks have a great senses of smell, the Great White can smell a drop of blood thousand of miles away. They’re hearing is very powerful , being able to hear the vibrations of prey distances of about 800 ft away and find the exact location through ‘ear stone’( Great white 3). A shark 's sense of hearing truly shows their uniqueness as an apex predator. In addition to great hearing they’re known to have great sight by being able to see up to 50ft away and transition into seeing in light and dark. Additionally sharks have a lateral line on their back that reaches from the front to the back tail, allowing
The morphology of whale sharks is mostly similar to aquatic fish species, but many specific traits help differentiate them from the rest. Whale sharks are the largest fish in the world and can reach a size of around 20 meters (Martins, C., and C. Knickle). This is often compared to the size of a school bus. The shark has a very large transverse mouth. They have 5 very large gill slits and have a larger first dorsal fin compared to the second one (Whale Shark). They have a distinctive spotted “checkerboard” pattern with stripes (Martins, C., and C. Knickle). It is not exactly known why they have this specific body marking. It is believed that the body markings act as a camouflage. The strange thing about whale sharks is that they have 300 rows of teeth that play no role in feeding (Martins, C., and C. Knickle).
The first step was to obtain the White Rat and to tie it in the supine position, anterior surface facing up in side the dissection pan. To tie the animal, we used butcher’s twine and secured the front and hinds legs using a “lasso” technique, careful not touch the sharp claws. To make the first insicion I had to locate the Xifoid Process of the rat (distal aspect of the sternum). Once I had located the Xifoid Process, I had to use forceps to pull the skin of the animal’s abdomen up and use the scissors to cut. The first incision is made from stem to sternum, cutting through the errectos abdomen muscle down to the groin. The second incision ion is perpendicular to the first below the diaphragm. Because of this technique we were able to open the abdominal cavity first. The third and forth incisions were made bilaterally above the legs. The last two incisions were made in upside down “V” shape on the collarbone, to expose the thoracic cavity. This dissection was both sharp, because of the use of the scissors and scapel and blunt because of the use of the probe and forceps to move organs and skin to expose other organs not yet identified.
One particularly interesting sea creature is the whale shark, formally known as Rhincondon typus it was first discovered in 1828 by Andrew Smith (Rowat 2012). This large fish is found globally in warm tropical oceans and prefers to stay within 200 meters of the ocean’s surface in waters ranging from 4.2 to 28.7 degrees Celsius (Stevens 2006). This creature can be found all across the globe in any warm tropical seas. Aggregations of whale sharks have been seen off the coast of Australia at times, although it is primarily a creature of solitude. Whale sharks are filter feeders that consume plankton as well as small fish and are harmless to humans. The whale shark is a species with a fascinating ecology, life history, behavior, anatomy