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Evolution
• From land mammals• Related to horse and sheep
Temperature Regulation
• Blubber – Also aids with buoyancy• Muscle movement generates heat• Body parts are not exposed to elements,
instead are all tucked in
Oxygen
• Blowhole on top of the head-better placement for animals who spend time with head under water
• Huge lungs that can fill/empty quickly (2 sec)• High gas exchange rate-whales absorb 90%,
humans only absorb 2% of oxygen• Can slow heart rate & shunt blood from non-vital
organs when diving
Anatomy
• Streamlined• Adults – no hair• Internalized body parts
(penis, mammary glands, ears) reduce friction
• No hind limbs• Fluke = tail; up/down;
used for identification
Senses
• Echolocation – biological sonar• Excellent hearing – songs used for communication• Good eyesight (except in dark where echolocation
is used instead)
Special Adaptations
• Collapsible lungs for when diving• Nostrils stay shut while diving• Do not get “the bends” (accumulation of Nitrogen
bubbles from diving)
Two Whale Types
• Suborder Odontoceti – Toothed Whales
• Suborder Mysticeti – Baleen Whales
Odontoceti – The Toothed Whales
• Grab food with teeth, don’t chew• Chase/hunt food so can dive deeper than baleen
whales• Most don’t migrate and travel in Pods (groups)• Examples: Sperm, Orca, Pilot, Dolphin, Porpoise
Mysticeti – The Baleen Whales
• No teeth – instead 600-800 baleen plates to filter krill through accordion-like pleats under mouth
• Their food lives nearer to surface, so they aren’t deep divers
• Examples: Blue, Humpback, Right
Reproduction
• Internal fertilization and development
• Bear live young• Nurse young• Young grow
extremely quickly• Low birth weight
Behaviors
• Breaching – jumping completely out of water• Spyhopping – face up out of water• Beaching – swimming up onto beach and
often dying when stuck there
Issues
Whaling:– Nearly wiped out many species– Was for food, oil, etc.– Marine Mammal Protection Act (MMPA) – bans
hunting/harassing marine mammals– International Whaling Commission (IWC) – makes
regulations pertaining to whaling