Dogfish Shark free essay sample

Dog Fish Shark Dogfish sharks are the second largest sharks, there body shape is rounded. Dogfish sharks have a variety of different parts. Smell, taste, hearing, sight, touch, and electro reception are six sensory systems that sharks use. All of there senses allow them to explore the environment and survive. There senses help them locate prey, avoid danger, and also find mates. Sharks nostrils or names are under the edge of there snout. There names are separate from there mouth and throat, they are uses exactly for. Each name Is divided Into two parts by a nasal flap. The flaps increase surface area, and provide the shark with a better opportunity of smell. When sharks detect a smell that they want to investigate or eat, the swim in the direction it is coming from and move its head back in forth. The names also detect chemicals in the water. The sharks eyes are highly sensitive to light intensity, they can also control the amount of light entering the eye by dilating there pupils. For a shark to focus Its controlled by the rectums muscles, this pulls the lens closer or further away. Sharks possess great vision In din light conditions. Sharks have an piper and lower eyelid but they usually dont meet, so it doesnt necessarily protect the eye. The dogfish sharks mouth is located underneath it. Spiracles located behind the eye on top of the head are used to provide oxygenated blood directly to the eye. The dogfish teeth are extremely sharp of coursed used for biting into its prey, the sharks tongue is rough for helping hold its prey. They eat squid, fish, and crustaceans. The dogfish shark as of all sharks have been around for as long as dinosaurs. If the shark Is a female the uterus Is the function of the egg developments, f a boy there is testes an oval shaped; dorsal to the liver. Males have claspers finger- like projections that assist in sperm transfer during mating, this occurs only in males. Ovaries are two cream colored organs. The shark heart has two halves, the atrium and ventricles, the heart is a specialized muscle. The pericardia cavity holds the heart and branching arteries, this cavity also protects the heart. The gill rakes Increase the surface area of the gills in order to take In more oxygen. The gill arches are made of cartilaginous arches that support the gills and also the gill rakes. Gill lits allow water to exit after passing over the gills, the dogfish sharks have five gill slits. The atrium is small and has functions in forcing blood into the ventricles, the ventricle is larger and functions in contracting blood into the rest of the body. The spiracles on top of the head, allows water to pass through the gills even when the sharks mouth Is closed. The lateral line Is a pale line beginning at the pectoral fins and ending at the pelvic fins, small openings that open Into the underlying line canal. The cloaca is the digestive tract exit and opening for the sex organs. are bundles of segmented muscle in the trump and tail, they are arranged in a zig zag pattern. The myosepta is where the muscle originates and inserts. Of the five fins the dogfish has only two are paired and they are the pelvic and pectoral fins. The five fins the shark has Is of course the pelvic, pectoral, the two dorsals, and the caudal as the liver, gallbladder, stomach, pancreas, etc. The liver functions in storage and flotation, it has three lobes. The gallbladder functions in the storage of bile secreted from the liver, it is located within the small love of the liver. The stomach is a J- haped organ, it has an cardiac part and pyloric part and functions in digestion. The pancreas has two parts, the ventral and dorsal and its a long and thin organ. The duodenum is right after the stomach it receives the bile from the gallbladder. After the duodenum the ileum and spiral valve absorbs nutrients like vitamin 812 and bile salts. The pyloric sphincter is the end of the stomach, a muscular ring which opens and closes the stomach to the intestines. The esophageal papillae helps move food to the stomach. The colon absorbs water and salts from the solid wastes before its stored in the rectum. The rectum functions in the storage of solid waste. The rectal gland controls salt concentration within the body and releases it into the rectum to be excreted. The spleen of the shark works with filtering the blood, caudal to the stomach and proximal the spiral intestine. The dorsal aorta is the distribution of blood throughout the body. Dogfish arent attack sharks, there shy, and rarely caught in swimming areas. Sharks are boneless fish with cartilage where the bone should be. The second dorsal fin is smaller than the first and both fins have spines at their origin. The caudal fin is asymmetrical with the upper lobe being larger. The Jaws are smooth edged short and oblique teeth are similar in both upper and lower Jaw. The dogfish habitat, the shark is found in cold and warm temperate oceans at temperatures between O and 15 degrees Celsius. It can be caught and located in the water column from the surface depths of meters in other words 2,400 feet. The average adult length is between 75 and 105cm, 30 or 40 inches. But they have been known to grow to 130cm weighing 201bs. the dogfish is long lived and slow growing and has an estimated life span of 30 to 40 years. Ages as old as 70 years have been determined for some dogfish from Columbia. Studies show that some dogfish can migrate great distances. The dogfish is an omnivorous opportunistic feeder eating whatever prey is abundant. The diet is comprised of small fishes such as coupling, cod, haddock, hake, herring, menhaden, and also raffish. They also eat invertebrates such as krill, crabs, pilchard worms, Jellyfish,,, squid, and octopus. Development in this shark is. The gestation length is longest known for sharks at an estimated 18-22 months. Young are born in the warmer waters off on the northeaster U. S and Nova Scotia during the winter months. Development in this shark is. The gestation length is the longest known for sharks at an estimated 18-22 months. Young are born in the warmer waters off of the northeastern U. S. and Nova Scotia during the winter months. The number of young born in a litter is dependent on the size of the female, larger females bearing more pups. However most litters are between 1 and 14 individuals that are approximately 20 to 30 cm in length. The average litter is 5-6 pups. Sexual maturity in males is reached at a total length of about 64 cm and 10 years of age. Females reach total length. Reproduction occurs offshore in the winter.