Whales

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