blue whale(藍鯨)

PHYSICAL DESCRIPTION: The blue whale is the largest mammal, possibly the largest animal, to ever inhabit the earth. Its body is long, somewhat tapered, and streamlined, with the head making up less than one-fourth of its total body length. Its rostrum (upper part of the head) is very broad and flat and almost U-shaped, with a single ridge that extends just forward of the blowholes to the tip of the snout. Its blowholes are contained in a large, raised "splash guard", and the blow is tall and straight and over 20 feet (6 meters) high. Its body is smooth and relatively free of parasites, but a few barnacles attach themselves to the edge of the fluke and occasionally to the tips of the flippers and to the dorsal fin. There are 55-68 ventral grooves or pleats extending from the lower jaw to near the navel.


COLOR: The blue whale is blue-gray in color, but often with lighter gray mottling on a darker background (or with darker spots on a lighter background). The underside of its flippers may be a lighter color or white, while the ventral (underside) of the fluke is dark. The blue whale acquires microorganisms called diatoms in the cold waters of the Antarctic and North Pacific and North Atlantic which give the underside of its body a yellowish green caste. Because of this yellow color, the early whalers gave it the name "sulfur bottom."

Length and Weight: The longest blue whale ever recorded was a 108-foot adult female caught during whaling efforts in Antarctica! In modern times, blue whales in the Southern Hemisphere reach lengths of 90-100 feet , but their Northern Hemisphere counterparts are smaller, on average 75 to 80 feet (23 to 24.5 m). Blue whales can weigh over 100 tons (99,800 kg). Females are larger than males of the same age, the largest perhaps weighing as much as 150 tons (136,000 kg).


Feeding: The blue whale is thought to feed almost exclusively on small, shrimp-like creatures called euphausiids or krill. During the summer feeding season the blue whale gorges itself, consuming an astounding 4 tons (3.6 metric tons) or more each day. This means it may eat up to 40 million krill a day. As a baleen whale, it has a series of 260-400 fringed overlapping plates hanging from each side of the upper jaw, where teeth might otherwise be located. These plates consist of a fingernail-like material called keratin that frays out into fine hairs on the ends inside the mouth near the tongue. The plates are black and measure about 20 inches (51 cm) in length toward the front of the mouth and about 40 inches (102 cm) at the rear. During feeding, large volumes of water and food can be taken into the mouth because the pleated grooves in the throat expand. As the mouth closes water is expelled through the baleen plates, which trap the food on the inside near the tongue to be swallowed.


Mating and Breeding: Recent research indicates that blue whales reach sexual maturity between the ages of 6-10 years, or when males average about 74 feet (23 m) and females are about 79 feet (24 m). Calves are born at intervals of 2 to 3 years and gestation is about 12 months. Calves are 23 to 27 feet (7-8.2 m) long at birth and 3 tons (2,722 kg). Calves nurse for 7 to 8 months and are weaned when they reach 52 feet (16 m) in length. At that time they weigh about 23 tons (20,900 kg). During the nursing period, calves consume 100 gallons (379 liters) of the fat-rich mother's milk each day, gain 200 pounds a day, or 8 pounds an hour, and grow 1 and 1/2 inches in length a day.

so long.........

PHYSICAL DESCRIPTION: The blue whale is the largest mammal, possibly the largest animal, to ever inhabit the earth. Its body is long, somewhat tapered, and streamlined, with the head making up less than one-fourth of its total body length. Its rostrum (upper part of the head) is very broad and flat and almost U-shaped, with a single ridge that extends just forward of the blowholes to the tip of the snout. Its blowholes are contained in a large, raised "splash guard", and the blow is tall and straight and over 20 feet (6 meters) high. Its body is smooth and relatively free of parasites, but a few barnacles attach themselves to the edge of the fluke and occasionally to the tips of the flippers and to the dorsal fin. There are 55-68 ventral grooves or pleats extending from the lower jaw to near the navel.


COLOR: The blue whale is blue-gray in color, but often with lighter gray mottling on a darker background (or with darker spots on a lighter background). The underside of its flippers may be a lighter color or white, while the ventral (underside) of the fluke is dark. The blue whale acquires microorganisms called diatoms in the cold waters of the Antarctic and North Pacific and North Atlantic which give the underside of its body a yellowish green caste. Because of this yellow color, the early whalers gave it the name "sulfur bottom."

Length and Weight: The longest blue whale ever recorded was a 108-foot adult female caught during whaling efforts in Antarctica! In modern times, blue whales in the Southern Hemisphere reach lengths of 90-100 feet , but their Northern Hemisphere counterparts are smaller, on average 75 to 80 feet (23 to 24.5 m). Blue whales can weigh over 100 tons (99,800 kg). Females are larger than males of the same age, the largest perhaps weighing as much as 150 tons (136,000 kg).


Feeding: The blue whale is thought to feed almost exclusively on small, shrimp-like creatures called euphausiids or krill. During the summer feeding season the blue whale gorges itself, consuming an astounding 4 tons (3.6 metric tons) or more each day. This means it may eat up to 40 million krill a day. As a baleen whale, it has a series of 260-400 fringed overlapping plates hanging from each side of the upper jaw, where teeth might otherwise be located. These plates consist of a fingernail-like material called keratin that frays out into fine hairs on the ends inside the mouth near the tongue. The plates are black and measure about 20 inches (51 cm) in length toward the front of the mouth and about 40 inches (102 cm) at the rear. During feeding, large volumes of water and food can be taken into the mouth because the pleated grooves in the throat expand. As the mouth closes water is expelled through the baleen plates, which trap the food on the inside near the tongue to be swallowed.


Mating and Breeding: Recent research indicates that blue whales reach sexual maturity between the ages of 6-10 years, or when males average about 74 feet (23 m) and females are about 79 feet (24 m). Calves are born at intervals of 2 to 3 years and gestation is about 12 months. Calves are 23 to 27 feet (7-8.2 m) long at birth and 3 tons (2,722 kg). Calves nurse for 7 to 8 months and are weaned when they reach 52 feet (16 m) in length. At that time they weigh about 23 tons (20,900 kg). During the nursing period, calves consume 100 gallons (379 liters) of the fat-rich mother's milk each day, gain 200 pounds a day, or 8 pounds an hour, and grow 1 and 1/2 inches in length a day.

還有更多關於藍鯨的網頁:
en.wikipedia.org/wiki/Blue_Whale
newport.pmel.noaa.gov/whales/bluecall.html
www.kidsplanet.org/factsheets/blue_whale.html
hk.knowledge.yahoo.com/question/?qid=7006110704113
hk.knowledge.yahoo.com/question/?qid=7006110703416
www.bluewhale-hk.com
www.bluewhaleltd.com
www.acsonline.org/factpack/bluewhl.htm

The blue whale is one of the rorquals, a family that also includes the humpback whale, fin whale, Bryde's whale, sei whale, and minke whale. On land an animal the size of a blue whale would be crushed by its own weight without the support of large heavy bones. Because its body is supported by water, as a sea animal, the need for heavy bones to support its weight disappeared. This, plus the availability of a large food supply, have made it possible for the blue whale to reach such an enormous size. The blue whale makes deep and rumbling sounds which can be felt as much as heard. These low-frequency sounds travel long distances through water, allowing blue whales to communicate with each other over hundreds of miles of ocean.

PHYSICAL DESCRIPTION: The blue whale is the largest mammal, possibly the largest animal, to ever inhabit the earth. Its body is long, somewhat tapered, and streamlined, with the head making up less than one-fourth of its total body length. Its rostrum (upper part of the head) is very broad and flat and almost U-shaped, with a single ridge that extends just forward of the blowholes to the tip of the snout. Its blowholes are contained in a large, raised "splash guard", and the blow is tall and straight and over 20 feet (6 meters) high. Its body is smooth and relatively free of parasites, but a few barnacles attach themselves to the edge of the fluke and occasionally to the tips of the flippers and to the dorsal fin. There are 55-68 ventral grooves or pleats extending from the lower jaw to near the navel.

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http://www.acsonline.org/factpack/bluewhl.htm

Live: Population and distribution today

A Blue Whale set against the backdrop of the Azores

Since the whaling ban, it is not well known whether the global Blue Whale population is increasing or remaining stable. In the Antarctic, best estimates show a significant increase since the end of illegal Soviet Union whaling, but numbers remain at under 1% of their original levels.[5] It has also been suggested that Icelandic and California populations are increasing but these increases are not statistically significant. The total world population was estimated to be between 5,000 and 12,000 in 2002 although there is great uncertainty in available estimates for many areas.[3] The Blue Whale remains listed as "endangered" on the IUCN Red List of threatened species as it has been since the list's inception. The largest known concentration, consisting of about 2,000 individuals, is the North-East Pacific population that ranges from Alaska to Costa Rica but is most commonly seen from California in summer. This group represents the best hope for a long-term recovery in Blue Whale population. Sometimes this population strays over to the North-West Pacific; infrequent sightings between Kamchatka and the northern tip of Japan have been recorded.

In the Southern Hemisphere, there appear to be two distinct subspecies, the Antarctic blue whale and the poorly-understood Pygmy blue whale, found in Indian Ocean waters. Recent abundance estimates for the Antarctic subspecies range from 1100[14] to 1700.[5] Research into the number of Pygmy Blues is on-going - the most recent reports suggest that there may be as many as 10,000 animals. If this is confirmed it will lead to a substantial upward revision in the global numbers.[4]

Migratory patterns of these subspecies are not well known. For example, pygmy blue whales have been recorded in the northern Indian Ocean (Oman, Maldives, Sri Lanka) where they may form a distinct resident population. In addition, the population of Blue Whales occurring off Chile and Peru may also be a distinct population. Some Antarctic blue whales approach the eastern South Atlantic coast in winter, and occasionally their sounds are heard off Peru, Western Australia, and in the northern Indian Ocean. In Chile, the Cetacean Conservation Center, with support from the Chilean Navy, is undertaking extensive research and conservation work on a recently discovered feeding aggregation of the species off the coast of Chiloe Island.

In the North Atlantic, two stocks are recognized. The first is found off Greenland, Newfoundland, Nova Scotia and the Gulf of Saint Lawrence. This group is estimated to total about 500. The second, more eastern group is spotted from the Azores in Spring to Iceland in July and August; it is presumed that the whales follow the Mid-Atlantic Ridge between the two volcanic islands. Beyond Iceland, Blue Whales have been spotted as far north as Spitsbergen and Jan Mayen though such sightings are rare. Scientists do not know where these whales spend their winters. The total North Atlantic population is between 600 and 1500.

Human threats to the potential recovery of Blue Whale populations include the accumulation of polychlorinated biphenyl (PCB) chemicals within the whale's blood, causing poisoning and premature death, and the ever-increasing amount of noise created by ocean traffic. This noise drowns out the noises produced by whales (see whale song), which may make it harder for whales to find a mate.

Efforts to calculate the Blue Whale population more accurately are supported by marine mammologists at Duke University who maintain the OBIS-SEAMAP (Ocean Biogeographic Information System - Spatial Ecological Analysis of Megavertebrate Populations), a collation of marine mammal sighting data from around 130 sources.

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