1. Give a brief overview of the evolution of fish. Fish were amongst the first known chordates about 500 million years ago. Therefore, they have a very elaborate and complicated evolutionary history. The first type of fish to appear during the Ordovician era were called Ostracoderms. They had their head and flanks covered with a bony armor while they had a cartilaginous back. The shield was used to keep off predators. The extinction of the Ostracoderms during the Devonian period saw the emergence of Placoderms. These types of fish were also armored, but their functional jaws distinguished them from their predecessors. They also have gills derived from their jaws that took over the specialized role of gaseous exchange. Evolution of …show more content…
What does it mean when we say that sharks are examples of chondrichthyan fish? Chondrichthyan fish such as sharks are a class of fish whose skeleton is made of cartilage. 5. Are these fish completely devoid of bone-like materials? Explain your answer. Their upper and lower jaws are also made of cartilage instead of bone. However, they are not devoid of bone-like materials because they have teeth that are made of bones. 6. How does the shark we will examine in the lab differ from other sharks? Sharks rely on several mechanisms to maintain their buoyancy in water. Firstly, their skeleton is made of cartilage that is less dense than bone. The second mechanism is the dynamic lift where they use their pectoral fins to maintain their buoyancy, just as the birds use their wings in the air. Liver contributes about 25% of the total mass of the shark. Moreover, it contains a natural compound known as Squalene. It is mainly used in the synthesis of Vitamin D and cholesterol. The compound has a lower density that assists the fish in maintaining buoyancy. However, fish with swim bladder have an advantage over sharks in that they can remain still in the water, unlike the shark that must stay in motion to control its …show more content…
How do sharks reproduce? While mating, the male shark fertilizes the eggs by inserting its clasper to the oviduct of the female shark. What happens after the fertilization varies from one species to another. There are shark species that lays their eggs while covered in a protective tissue. These eggs later hatch into young fish. Other species give birth to live young ones and then abandons them. 8. Briefly describe some of the ways the shark is able to detect its prey in the water. Emphasize the ways sharks rely on senses other than vision. Sharks use their sensory, hearing and sight senses to detect their prey in the water. They have sensory receptors forming what is referred to as the lateral line. These receptors detect any potential prey and then it moves towards the direction of the stimulus. Electroreception is another mechanism used by sharks to detect their prey. In electroreception, the Shark picks up frail electrical signals produced by muscle contraction of prey that is close. 9. What is the full taxonomic name and “popular name” of the shark that we will be examining in the lab? The popular name of the shark is the Smallfin gulper shark while its taxonomic name is the Centrophorus
...s in the water, as well as quick change in pace and direction. This again is to evade predation.
In addition to Western Australia’s targeted species being Great White sharks, Tiger Sharks and Bull Sharks, the QSCP contains a variety of additional target species, some of which have never been
Mojetta wrote about prehistoric sharks, and the history of these creatures. According to Angelo Mojetta, author of Sharks, Cladoselache genus, one of the first prehistoric sharks, was buried in sediment that kept it preserved. Unlike other sharks, Cladoselache genus had a circle of tiny plates around it’s eyes for protection against it’s victim’s attempts to fight back. These sharks lived over 400 million years ago. Sharks of the past could mostly be identified by their teeth, because shark’s bodies are made of cartilage. Another shark that was focused on was called, Stethacanthus. This shark had a very unique look. Stethacanthus had a brush like decoration on the top of it’s head, and an extra fin like part that had the same bristle like decorations on it. These characteristics were thought to be used as suction cups, to hitch rides from larger fish. One of the most famous sharks that looks like an over...
The differences between these two species concerning appearance,diet,size and other important factors of the species lives are important to know in case of close encounter and need of survival. It is important to know what they look like so to know their special abilities so they will be easier to evade. Hammerhead sharks and bull sharks are very aggressive towards their prey and take over most oceans. These species are very important because if you want to study them for research,then you should know their normal personality traits for easier behavioral comparisons. The appearance and design of hammerhead and bull sharks are very different.
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.
“In life, sharks are very flexible. Even hammerheads and large ocean sharks are quite flexible,” Lauder said. “If you watch a shark swim, the head does not move very much, so it could be that the denticles on the head are mostly reducing drag, but those on the tail are enhancing thrust. But we don’t know what that balance may be. Ultimately, though, one of the key messages of this paper is that shark skin needs to be studied when they’re moving, which hadn’t been done before.”
But how do the plakton know that the water is moving? And what forces act on animals as they swim?
When the word Shark comes to mind most people think of a monster that feeds on humans and is an enemy of all living beings. Contrary to popular belief less than 10 percent of sharks are known to attack humans unprovoked. Sharks are classified under the class of Chondrichthyes, which is fish that have characteristics of a skeleton made of cartilage, jaws, paired fins, and paired nostrils. The superorders are divided into two groups, which are Batoidea that have rays and their relatives and Selachii, which are sharks. Scientists have found isolated spines, teeth, and scales that appeared 350 to 400 million years ago in the Devonian Period known as "Age of Fishes". Most modern sharks have evolved 100 million years ago when dinosaurs lived on earth. (Matthews, 1989) Sharks have been known to inhabit tropical and temperate seas as well as some cold and polar seas. Migration of sharks is poorly understood due to not all species migrating. And in the species that do migrate the distance may be short or long and is based on availability of the food and environmental cycles. One American biologist Eugenie Clark is the world leader in shark study, she was the first person to learn how sharks behaved in captivity and how well sharks had the ability to understand.
The Grey Nurse Shark, also known as a Carcharias taurus is from the Odontaspididae family and is a species of fish that is critically endangered around Australia.
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
Thesis: Sharks should be conserved because they are an important part of the ocean, attacks are often incidental, and human behavior influences the behavior of sharks.
Most people think that sharks are large, fast-swimmers, and savage predators. This is true of some species and groups should be interested of the appealing aspects of biology found within it: all sharks have an excellent sense of smell; some can detect electrical discharges; some sharks give birth to one of the
Reproduction: They are able to reproduce when they are about 10-12 years old. The breeding takes place at night, in shallow waters and the male mounts the female. Mating occurs in early May and by late June/July the female lays 35-50 eggs.
Description: These fishes are characterized by their bright yellow to orange color with three distinctive white bars across its body. They are among the most recognizable reef-dwellers. Their average length –as reported- ranges about 11 cm.
There are nearly 400 different types of sharks that have been identified to this day, yet there are still new sharks being recognized every day. Atelomycterus marmoratus, also known as the coral catshark, is a member of the scyliorhinidae family, which is the largest shark family. The coral catshark belongs to the animalia kingdom, chondrichthyes class, elasmobranchii subclass, and the A. marmoratus species. Another common name for the coral catshark is the marbled catshark, which came from the original name, Scyllium Marmoratum. (Marmoratum being Latin for marbled) The life of the coral catshark is exposed and defined by looking in to the physical description, habitat and adaptations, feeding behavior, life history, and conservation status and threats.