1. Powerful tail flukes move up and down vertically to propel baleen whales through the water. Flukes are powered by muscle masses in the upper and lower regions of the tail stock.
2. Rorquals, which are more streamlined than other baleen whale families, are known for attaining the fastest speeds of baleen whales. It is estimated that the fastest rorquals can reach speeds near 32 kph (20 mph).
3. Other species travel at slower speeds. Gray whales migrate at about 10 to 11 kph (6-7 mph).
1. Baleen whales are not known to dive regularly to great depths. Many species feed in relatively shallow areas of the continental shelf. Gray whales make shallow dives of 15 to 50 m (50-165 ft.), but may dive as deep as 120 m (390 ft.) to feed in their polar feeding grounds. Humpback whales dive at least 148 m (485 ft.) , and fin whales dive to a maximum of about 355 m (1,165 ft.).
2. Dives last anywhere from 3 to 20 minutes or more depending on the species.
3. All marine mammals have special physiological adaptations during a dive. These adaptations enable a baleen whale to conserve oxygen while underwater.
a. Baleen whales, like other mammals, have a slower heart rate while diving.
b. When diving, blood is shunted away from tissues tolerant of low oxygen levels toward the lungs, heart, and brain, where oxygen is needed.
c. Compared to terrestrial mammals, baleen whales have twice the concentration of red
blood cells and up to nine times the concentration of the oxygen-binding protein
myoglobin. Myoglobin and red blood cells store oxygen and provide tissues with oxygen
while the whale dives.
1. Baleen whales breathe through two blowholes on top of the head. A baleen whale holds its breath while underwater, then opens its blowholes to exhale explosively. It quickly inhales, and then closes the water-tight seals on the blowholes before diving. For a gray whale, each exhalation/inhalation takes about two seconds.
2. Depending on the activity level, baleen whales breathe several times at the surface before submerging again for several minutes. For example, right whales usually stay underwater for 5-15 minutes, then surface and blow five to ten times at 15 to 30 second intervals before diving again.
3. The visible spout of a whale is not water rising from the blowhole. It's actually water vapor condensing as the respiratory gases expand in the open air.
4. Baleen whale species can sometimes be identified by the size and shape of the spout.
a. Right whales have a low bushy spout.
b. A blue whale's spout may reach 9 m (30 ft.) in the air.
c. A gray whale's spout looks heart-shaped when viewed from behind.
d. Minke whales sometimes have no visible spout.
5. Baleen whales exchange 80% to 90% of their lung air volume with each breath. (Humans
exchange only about 17% to 20% of their lung air with each breath.)
Baleen whales have been observed at the surface of the water virtually motionless for
minutes at a time, but sleep has not been well studied in baleen whales.
1. Heat loss in water is about 27 times greater than in air at the same temperature.
2. Baleen whales maintain a core body temperature somewhere between about 36.6 degrees C and 37.2 degrees C (98-99 degrees F). This temperature is similar to that of other large mammals. There is a heat gradient throughout the blubber to the skin.
3. A blubber layer just underneath the skin is made of fat cells and fibrous connective tissue. Blubber insulates the whale from the cold ocean water.
a. Blubber makes up 27% of a blue whale's body weight, 23% of a fin whale, 21% of a sei whale, 29% of a gray whale, and 36% to 45% of a right whale.
b. The blubber layer can reach a thickness of 50 cm (20 in.) on a bowhead whale.
c. The thick layer of blubber results in a streamlined, fusiform (torpedo-shaped) body, making a whale energy-efficient for swimming.
d. Blubber is an energy reserve.
4. A baleen whale's fusiform body shape and reduced limb size decrease the amount of surface area exposed to the external environment. This helps conserve body heat.
5. A baleen whale's circulatory system adjusts to conserve or dissipate body heat and maintain body temperature.
a. Some arteries of the flippers, flukes, and dorsal fin are surrounded by veins. Thus, some heat from the blood traveling through the arteries is transferred to the veinous blood rather than the environment. This countercurrent heat exchange aids whales in conserving body heat.
b. When a baleen whale dives, blood is shunted away from the surface. This decrease in circulation conserves body heat.
c. During prolonged exercise or in warm water a whale may need to dissipate body heat.
In this case, circulation increases in veins near the surface of the flippers, flukes, and
dorsal fin, and decreases in veins returning blood to the body core. Excess heat is shed
to the external environment.
SeaWorld/Busch Gardens Animal Information Database
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