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The Bottle-Nosed Dolphin Essay, Research Paper
The Bottle-nosed Dolphin is the most studied and generally the best-known species of dolphin. Bottle-nosed dolphins are classified “Tursiops truncates” in scientific name, and belong to the family Delphinidae, in the suborder Odontoceti, order Cetacea.
This animal is a very intelligent individual. Bottle-nosed dolphins are commonly found in zoos or marine parks because of their capability to perform tricks. They can jump through hoops 5 meters high because of their incredibly powerful tail. As well as jumping, Bottle-nosed dolphins can raise themselves upright out of the water and travel backwards, by threshing their tails.
Bottle-nosed dolphins are generally coastal creatures, occurring along almost all tropical and temperate coasts, although offshore varieties also occur. In addition, the Bottle-nosed dolphin is called the “all-ocean” dolphin, meaning that it lives in every ocean. It is common for a school of 20 dolphins to live together in coastal regions, but school of 200 dolphins are found in the offshore verities. These schools do not seem to have a leader and generally stay together for life.
Such sea life as shrimp, squid, small sharks, other vertebrates and fish are all a part of a Bottle-nosed dolphins diet. When they find a large school of fish, several schools of dolphins join up to form groups of up to 1000 dolphins. They work together to head and catch the fish. Another feeding method the Bottle-nosed dolphin has developed is chasing the fish on to mud banks and snaps them in the air.
Bottle-nosed dolphins are an extremely adaptable mammal. For example, the Atlantic Ocean form tends to be a little smaller and stockier with a shorter rostrum (nose) compared to the Pacific form. In Scottish waters, Bottle-nosed dolphins are chubby with a dark gray complexion, while the in Australian waters, Bottle-nosed dolphins are thin, light gray appearance, with a dominant circle around each eye. The reason why this dolphin may change its physical appearance is because there may be more fish in Scotland, or the prey may be a slower breed, making the Bottle-nosed dolphin not work as hard for its food, therefore creating a chubbier breed of Bottle-nosed dolphin compared to other parts of the world. Bottle-nosed dolphin have recently been introduced and are now bonding with humans in dolphin watching and swim-with-dolphin tourism activities in nature.
A female Bottle-nosed dolphin will mature between the age of 5 to 12 years, and males at 9 to 13 years. Bottle-nosed dolphins live for 30 to 50 years and grow from about a 6-inch calf, up to 10-foot long mature adult in some cases. The female Bottle-nosed dolphin has a gestation period of 12 months long, after which the mother nurses the calf for about 18 months. During this period, the calf will learn practical skills such as how to find and capture food, how to recognize other dolphins. Bottle-nosed dolphins have a multimale, multifemale mating society. There no aggression when it comes to mating from either male or female.
Generally, Bottle-nosed dolphins are a dark gray or black colour above, with a lighter colour on its stomach, which can change to a flushed pink colour in warm water. These animals have a prominent, curved back fin with a thin trailing edge that readily tatters. The Bottle-nosed dolphin gets its name from its rostrum, which is shaped like a bottle.
Bottle-nosed dolphins were hunted in the 19th and 20th century for their skin, but now are a legally protected species but killings still occurring due to angry fishermen and fishing nets. If this creature were to of become extinct, I believe there would not of been that greater change because the Bottle-nosed dolphin has no immediate predators and feeds on a wide range of sea life.
Bottle-nosed dolphins rarely fight with each other because there is no power to be gained by it. They communicate by means of whistles and rasping sounds. Also, the use of echolocation is practiced, which is sending high-frequency clicks that bounce off prey and other objects and use the returning echoes to identify the objects. Bottle-nosed dolphins have been known to swim with ships for food, which is a common occurrence for cruise ships. As for migration, this dolphin can live in any ocean it wishes to, except the Antarctic seas, but commonly sticks to the same oceans or sea for its entire life.
Bottle-nosed dolphins have great hearing capabilities, just as well because they use it like we use the power of speech. For example, they have a highly developed auditory cortex of the brain, with the auditory nerve carrying 67,900 cochlear fibers, which is twice as much as normal humans. Bottle-nosed dolphins respond to tones within the frequency range of 1 to 150 kHz (average hearing range for humans is about .02 to 17 kMz.) The reason why they have great hearing is because of their lower jaw and ear acts as a sound receptor. Tones of about 20 kMz are picked up through the lower jaw, which then travels to a fat-filled cavity, which conducts sound waves through to the middle ear.
A Bottle-nosed dolphins have an acute vision both in and out of the water. They have a highly developed tapetum lacidum, which is a light-reflecting layer that reflects light through the retina a second time, giving Bottle-nosed dolphins enhanced vision in dim light. Although it is not confirmed, rods and cones have been found in their retina, giving the question weather or not they can see colour. Other senses such as taste, smell and touch, are still to be questioned but through observations and behaviour, it is believed that they have a well-developed senses of touch.
A Bottle-nosed dolphin skeletal system is believed to be originated from the basic mammalian skeleton, but has gone through a number of changes. Firstly the forelimbs have been modified into flippers and the bones of the hind limbs have disappeared altogether. Such bones as the rib cage and the spin have also undergone transformation in the fact that they have cured and caved-in due to water pressure. These creatures hold their breath for about 15 minutes before having to submerge for air. The Bottle-nosed dolphin is an amazingly strong creature. Because it never stops swimming, the Bottle-nosed dolphin has a very powerful tail, which is capable of supporting its weight of about 400 kg.
Another factor of a Bottle-nosed dolphins anatomy, which needs mentioning, is its blood circulation. The remarkable feature of this system is its retia mirablilia. This feature is also labelled “wounder nets”, which is when the blood vessels create “nets” to protect vital organs form the effects of water pressure.
In conclusion, the Bottle-nosed dolphin has many incredible factors, which make it one of the smartest and elegant mammals in every ocean in the world.
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