Sanmin Book 1 Unit 9: Sanmin Book 1 Unit 9 The Blue Whale Giants of the Sea (海中的巨人): Giants of the Sea (海中的巨人) 1.The Cetacean (鯨類動物) Cetaceans are divided into two groups: (1)Toothed Whales(齒鯨): killer whales,dolphins…
(2)Baleen Whales(鬚鯨) : blue whales, humpback
2. What is baleen(whalebone)?: 2. What is baleen(whalebone)? (1)Baleen is composed of keratin(角質), a protein compound that also makes up human hair and fingernails.
(2) The blue whale uses this sieve-like(篩子般的) device to filter small fish, krill(磷蝦) and plankton.
(3) They usually take in huge mouthfuls of water, the baleen traps the prey and water is forced back out of the mouth.
3.Are whales a type of fish?: 3.Are whales a type of fish? No, whales are mammals, like us.
4.What are mammals?: 4.What are mammals? Scientific Classification
Class(綱 )--Mammals. Mammals are characterized by the following features: 1. Mammals breathe air with lungs.
2. Mammals maintain a constant high body temperature
independent of their surroundings. 3. Mammals have a four-chambered heart. 4. As a rule, mammals bear live young. (Two primitive
mammals are exceptions to this rule: the duckbilled
platypus and the spiny anteater both lay eggs.) 5. Mammals nurse their young with milk. 6. Mammals have hair, at least at some stage in their
development . 5. A brief comparison of whales and fish.: 5. A brief comparison of whales and fish. 6.Some facts about whales.(1) Why do they blow?: 6.Some facts about whales. (1) Why do they blow? 1.They are in fact breathing through their lungs.
2.They have to surface to breathe from time to time.
3.The blowholes on their heads are their nostrils (noses).
4.When they dive under the sea, they close their blowholes tightly, and when they resurface, they immediately open up their blowholes,exhale ,and inhale. (2 )Why do they breach?(破浪而出): (2 )Why do they breach?(破浪而出) When a whale or a dolphin jumps out of the water,or slaps the water loudly with its flippers or tail, there are always big splashes and huge noises.
They can communicate with their companions within a certain distance through the huge noise they make when slapping the water. (3) Why do they sing?: (3) Why do they sing? The songs whales sing may be love songs that males sing to females.
Cetacean songs also help them to navigate under the sea.
The cetaceans can find prey or determine their routes according to the echoes of their voices.
The most moving songs come from the humpback whales.
1.Classification Blue whales are baleen whales. : 1.Classification Blue whales are baleen whales. Kingdom(界-- animals
2. General Description: 2. General Description The blue whale is the largest animal that ever lived on Earth. It is also the loudest animal on Earth, louder than a jet.
They live in pods(small groups and frequently swim in pairs.
Its skin is usually blue-gray with white-gray spots.
It has 2 blowholes and 5-30cm thick layer of blubber.
It has pleated throat grooves that allow its throat to expand during the huge intake of water during filter feeding.The 50-70 throat grooves run from the throat to mid-body. 3. Size: 3. Size A big blue whale can be 100 feet (30m long and weigh up to 150 tons (136,000kg.
That’s as large as a Boeing jet 737.
Its heart is as large as a small car. Fifty people could stand on its tongue.
Females are larger than males of the same age. A comparison of the size of the blue whale and other interesting animals: A comparison of the size of the blue whale and other interesting animals 4. Habitat and Range: 4. Habitat and Range 1.Blue whales are found throughout the world’s oceans.
2.They generally spend winters in temperate and subtropical zones, migrating toward the polar regions in spring and summer. 5. Reproduction: 5. Reproduction Blue whale breeding occurs mostly in the winter to early spring while near the surface and in warm waters.
The gestation period is about 11-12 months and the calf is born tail first (this is normal for cetaceans).
The newborn instinctively swims to the surface within 10 seconds for its first breath; it is helped by its mother, using her flippers.
Within 30 minutes of its birth the baby whale can swim.
Slide19: Twins are extremely rare(about 1% of births); there is almost always one calf.
The baby is nurtured with its mother’s fat-laden milk(it is 40-50% fat) and is weaned in about 7-8 months.
The mother and calf may stay together for a year or longer, until the calf is about 45 feet long (13m).
They reach maturity at 10-15 years.
6. Life Span: 6. Life Span Blue whales have a life expectancy of 35-40 years. 7. Population Count: 7. Population Count It is estimated that there are about 10,000-14,000 blue whales world-wide.
Blue whales are endangered species.
These whales(and many other large whales) were over-hunted for many years,since their meat, oil, and other body parts are very valuable.
Since whale hunting has decreased in the last few decades, their populations are starting to recover.
8. History and Status: 8. History and Status Blue whales once were considered too difficult to hunt because of their speed and tremendous size.
However, with the introduction of factory ships and the harpoon gun in the 1920s, blue whales were hunted intensively.
The slaughter peaked in 1931when over 29,000 were killed in one season.
By the 1960s, they were nearly extinct.
The International Whaling Commission (IWC) banned all hunting of blue whales in 1966 and gave them worldwide protection.
Today,blue whales face threats from entanglement in fishing nets,pollution,and illegal whaling.
Going Whale Watching: Going Whale Watching Going Whale Watching in Taiwan: Going Whale Watching in Taiwan There are about 80 species of cetaceans in the world, and as many as 31 species can be observed in the waters surrounding Taiwan year round.
The most common ones in these waters are smaller species such as Risso’s dolphins,bottlenose dolphins and Fraser’s dolphins etc.
Occasionally, medium-sized and large cetaceans such as killer whales,sperm whales or humpback whales also grace the waters off Taiwan.
Slide26: May to September is the prime time for whale-watching activities.
The first whale watching boat of Taiwan sailed out from Hualien Harbour in July 1997..
Today, there are at least 33 whale watching boats on the east coast of Taiwan, mainly in the counties of Ilan, Hualien and Taitung.
Saving Whales: Saving Whales A brief History of Conservation of Cetaceans in Taiwan: A brief History of Conservation of Cetaceans in Taiwan Taiwan Cetacean Stranding Network (TCSN: 0928-
539977 我想救救鯨鯨 ) was founded.
1997 Whale-watching off east coast of Taiwan initiated.
Taiwan Cetacean Society (TCS) was founded.
A mature male Risso’s dolphin ( A-tung) was
released on Sep. 8.
IFAW( International Fund for Animal Welfare)
reported that the whale–watching development in
Taiwan was the rapidest in the world.
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