Transcript Anatomy and Physiology of Whales

By. Sara Kowalski
Toothed Whales vs. Baleen Whales
Toothed Whales
(Odontoceti)
• Toothed whales are
predators that use
their teeth to catch
their prey
Baleen Whales
(Mysticeti)
• Baleen whales have a
sieve-like structure
called baleen that
catches huge
amounts of tiny krill
Anatomy of Baleen Whales
• In general, baleen whales weigh about 1 ton for each foot of
length
• Females are generally larger than males
• All Baleen Whales have two blowholes
• All toothed whales have a single blowhole
Anatomy of Baleen Whales Cont.
Skeletal System
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In all whales, the ribs are bound to the spine by flexible cartilage, which allows the
ribcage bend and adapt to higher pressures when diving.
The neck is made of compacted vertebrae to stiffen neck when diving and swimming
fast
The front flippers have a shortened humerus to stiffen into a paddle, they have extra
phalanges, but only four sets to form into a flipper for steering
Some whales have a vestigial pelvis — a remnant from four-legged land ancestor
Numerous vertebra behind pelvis, giving a lot of flexible movement for up/down
powering of fluke
Chevron bones for muscle attachment
 Fluke starts where chevron bones stop
Whale Digestion System
 Many whales have three stomachs, although some
whales, like the sperm whale, only have two
 The three stomachs:
 The first stomach (forestomach) mechanically crushes the
food
 The second stomach is where chemical breakdown begins
 The third stomach is the pyloric stomach and secrets
gastric juices
Circulatory System
 Warm blooded
 Has a large amount of red blood
cells
 Increases amount of oxygen carried
 The heart of a whale can make
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up about 2% of its body weight
The heartbeat of a whale varies
from whale to whale
In general, larger animals have a
slower heat rate than smaller
animals
Average heart rate of large
whales are about 10 to 30 heart
beats per minute underwater
Whales slow their heart rate
when they dive, conserving
oxygen and allowing them dive
longer
Thermoregulation
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Baleen whales maintain a body temperature between about 36.6°C and 37.2°C (98-99 °F)
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A blubber layer just underneath the skin is made of fat cells and fibrous connective tissue
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There is a heat gradient throughout the blubber to the skin
Blubber makes up 27% of a blue whale's body weight
23% of a fin whale
36% to 45% of a right whale
The blubber layer can reach up to a thickness of 20 in. on a bowhead whale
Thick layer of blubber results in a streamlined body, making it energy-efficient for
swimming
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Blubber is an energy reserve
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Reduced limb size decrease the amount of surface area exposed to the external
environment
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A baleen whale's circulatory system adjusts to conserve or dissipate body heat and
maintain body temperature
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This helps conserve body heat
When a baleen whale dives, blood is shunted away from the surface. This decrease in circulation
conserves body heat
Muscular System
 All whales have muscles with a high level of
Myoglobin
 This is a red pigment similar to hemoglobin that stores
oxygen in the muscles for use during deep dives
 Muscles prominently control the tail and the flukes
 Tail provides forward motion
 Flukes are used for steering
Senses
 SIGHT:
 vision is not extremely important to them except when they're at or
near the surface
 HEARING AND ECHOLOCATION:
 Dolphins and toothed whales have excellent hearing and use
echolocation to sense objects
 Baleen whales don't use sophisticated echolocation, probably because
they don't have to stalk prey
 SMELL:
 Have a very limited or non-existent sense of smell
 The olfactory bulb in the brain is primary for sense of smell, but these
olfactory bulbs are reduced in baleen whales and are absent in toothed
 TASTE:
 Research on the existence whales' taste buds is mixed and contradictory
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Experiments have shown that dolphins do have a sense of taste
 TOUCH:
 Skin is very sensitive to touch
 MAGNETISM:
 Whales may use the magnetic field of the Earth for navigation purposes
on their long migrations across the oceans
 It is not known how they sense magnetism
Resources
 http://www.enchantedlearning.com/subjects/whal
es/anatomy/
 http://science.howstuffworks.com/zoology/marine
-life/baleen-whale1.htm
 http://www.seaworld.org/animal-info/infobooks/baleen/physical-characteristics.htm
 http://oceantoday.noaa.gov/whaleanatomy/