Bottle Nose Dolphin essay example

1,669 words
This discussion tells the main characteristics of the Bottle nose dolphin. It explains the population, where many bottle nose dolphins live. It tells about the visible features of the dolphin and how they are used. It explains reproduction and how long it takes.

It also tells you about all the senses the bottlenose dolphin has and how important they are for their survival. Bottlenose dolphins are classified as "Tursiops Truncatus (Internet). Scientist believe the ancestors of bottle-nosed dolphins lived on land. Blood chemistry studies have shown that dolphins are "artiodactyl" or cows and camels! X-rays of flippers are pectoral fins which shows bone structure similar to the human hand, as shown in the picture to the right. Bottle nose dolphins live in tropical waters throughout the world.

In the Pacific ocean, they are found from Northen Japan and California to Australia and Chile. They are also found off shore in the eastern tropical pacific as far as the Hawaiian Islands. In the Atlantic ocean they can be found from Nova Scotia and Norway to Patagonia and tip of South Africa. They are most abundant along the United States and Cape Cod through the Gulf of Mexico.

Also bottle nose dolphins can be found in the Mediterranean Sea and in the Indian Ocean from Australia to South Africa. In the northwest Atlantic there are two ecotype. They can be differentiated by skull and body measurements and by blood (Internet) The coastal ecotype seems to be adapted for warm, shallow waters. Its smaller body and larger flippers suggest increased maneuverability and heat dissipation. They are usually in harbors, bays, lagoons and estuaries. The offshore ecotype are adapted for cooler, deeper waters.

Certain characteristics of their blood indicate that this form may be better suited for deep diving. Its larger body helps to conserve heat and defend itself against predators. The world wide population of dolphins, is unknown. In the United States Gulf of Mexico, their estimated to be about 67,000. In the north western Pacific and along Japan it is estimated to be about 35,000. In the Northwestern Atlantic ocean there is about 11,700.

Also, in the Mediterranean there is estimated to be about 10,000 (Internet). Female bottlenose dolphins become sexually mature when there about 5 to 12 years old and about 7.5 feet long. Males become sexually mature when they " re about 10 to 12 years old and about 8 to 8.5 feet long. Bottle nose dolphins may breed throughout the year.

Seasonal peaks, vary by location. Along the west coast of Florida the peak season is May, along the coast of Texas it is March. Along the Florida Indian River Lagoon peak season is April and August and in the Pacific ocean it is fall. Females can bare a calf every 2 years, but the average is 3 years. They hold their young for an year (Internet).

Calves are born in the water. When the female goes into labor she will stand on her head, lifting her tail out of the water to the level of her genital slit and alternately arching her back and flexing her abdomen. When the calf is out, the newborn will swim unattended to the surface for its first breath. The mother will use her tail and her rostrum to guide the calf to the traveling position, just below her dorsal fin. The calf learns to position itself close to its mothers side so it can "hitch a ride". Infants usually begin nursing within a few hours of birth.

Nursing hours are brief, each last five to six seconds on average. When separated from their mothers bottle nose dolphins usually join groups their own age, typically between three to thirteen years of age. Daughters usually go back to there parents more frequently then their sons (Wells, 1991). Bottlenose dolphins can eat 4% to 5% of their body weight per day. (Internet). They do not chew their food, they swallow the fish whole.

In open waters bottle nose dolphins travel in pods. When catching food they circle large school of fish. They take turns charging into the school of fish (Prevost, 1995). Bottle nose dolphins find their food with echolocation. Echolocation allows the dolphins to find food and keep away from danger and also communicate with other dolphins. Echolocation consists of clicks (puls ive) and whistles (to nels) that travel through the water.

When the sound returns to the dolphin it tells the dolphin where the object is, how large it is and how fast it is moving. (Prevost 1995), as shown in the diagram above. Also studies have shown that the bottle nose dolphin can stun its prey. "They use a big bang- a high-amplitude, low-frequency sonic impulse lasting hundred of milliseconds-or a series of bangs to possible stun or disorient their prey. They may use this method for stopping their larger, faster, free swimming prey.

(Sullivan, 2002). Bottlenose dolphins can travel up to 2 to 5 km per hour, sometimes up to 30 km per hour if alarmed. They can dive up to 300 miles. When resting the bottle nose Dolphin rises slowly to the surface with the head and dorsal fin breaking to the water, and remain afloat for up to 10 seconds then slowly submerge again (Internet). Bottle-nosed Dolphins have no sense of smell, but they have a sense of touch.

Touch to the bottlenose dolphins shows feelings. They can see well in and out of water and in by listening to returning echos. Dolphins have a well, developed sense of hearing. Bottle-nosed dolphins respond to tones within the frequency range of 1 to 150 kHz. The average hearing range for humans is about.

02 to 17 kHz. Peak range is about 40 to 100 kHz. Bottle-nosed dolphins can also detect sounds frequency of less than 1 KHz. Most sound is received through the lower jaw. Also through soft tissue and bone surrounding the ear (Internet), shown in the picture above. Dolphins have curiosity for self awareness.

They can recognize their own reflection just like humans do. During a serious of trials the bottle nose dolphin ignored spots that left no visible marks. After there were ink applications that were visible the dolphins began positioning themselves in front of mirrors. The dolphins repeatedly would view their own reflections. After the markings were gone, the dolphins spent little time in front of the mirrors (Bower, 2001). The typical color of the bottlenose dolphin is gray and can also be grayish-brown.

The belly is usually white and sometimes pink. The lower jaw and anal regions are also the same color as the belly. Their flippers are curved slightly and pointed at the tips. The bottle-nosed dolphins, use their flippers to steer and with help from the flukes, to stop. As shown in the picture at the bottom. The flukes are each lobed of the tail.

Flukes are flattened pads made of tough, dense, fibrous connective tissue, without bone or muscle. The spread of the flukes are about 20% of the tail. The dorsal fin is made just like the flukes. The dorsal fins help stabilize as the dolphin swims. Flukes and flippers and the arteries in the dorsal fin are surrounded by veins to help maintain body heat in cold water. The bottle nose dolphin's head is usually, 3 inches, marked by a lateral crease.

The teeth are conical and interlocking. The teeth are designed for grabbing food. Teeth vary, most have 20 to 25 teeth on each side of the upper jaw. The lower jaw has a total of 18 to 25. The total of teeth for a bottle nose dolphin is about 75 to 100 teeth. The eyes are on each side of the head, near the corners of the mouth.

The ears are located just behind the eyes. Also bottle nose dolphins have a blow hole located on the top, center, of the head. The blow hold is covered by a muscular flap, to open the blowhole the dolphin contracts the muscular flap (Internet). Bottle nose dolphins can live up to 48 years of age. The age can be determined by a sliced section of a tooth and counting these layers. As shown in the diagram below.

(Internet). In conclusion, bottle nose dolphins are highly populated. Classified as the Tursiops Truncatus. Bottle nose dolphins are very intelligent animals. They live throughout the world and adapt to the environment that they live in. Bottle nose dolphins often return to their parents.

They have many senses that are highly developed. These heightened sense are a key to the bottle nose dolphin survival. Also the ancestors of the bottle nose dolphin, is believed that they were land species. Literature Cited Bower, B. 2001. Dolphins May Seek Selves in Mirror Images. Science News 59 (18) Prevost, J.F. 1995.

Dolphins Bottlenose Dolphins. Abdo and Daughters, Minneapolis, Minnesota. Sullivan, R., G. Hickey 2002. Dolphins Stun Prey With Sound. Nature Australia; Winter 27 (5) 10 Wells, R. 1991.

Bringing Up Baby. Natural History 100 (8) April 23, 2003. Marine Dolphins. Retrieved from the world wide web [ web on October 13, 2003 Bottlenose Dolphins.

Retrieved from the world wide web [ web October 11, 2003 Bottlenose Dolphins, Fact File. Retrieved from the World Wide Web [ web October 17, 2003.