CETACEA

WHALES, DOLPHINS & PORPOISES

FISH-LIKE CHARACTERISTICS

• Convergent evolution due to environmental pressure

• Front flippers, no rear flippers

• Has a dorsal fin for balance

• Tail called a fluke & is horizontal with up & down motion

Adaptations

• Streamlined body to reduce water resistance

• Nostrils are blowholes on top of head

• Blubber for insulation & buoyancy

Baleen Whales - toothless

• Filter feed on fish & krill

• Baleen –rows of fibrous plates from upper jaw

• Some have throat grooves that expand

• Examples: blue whale, humpback, right

Toothed Whales

• Carnivorous, use teeth to catch prey & swallow it whole, diet includes squid, fish & seals

• One blowhole

• Examples: sperm whale (largest), dolphins & porpoises

Interesting Facts

• Sperm whale: spermaceti in head is used as a high quality wax

• Also ambergris from intestine is in perfume

• Dives to great depths to feed on giant squid

ORCA – KILLER WHALE

• Distinctive black & white coloration

• High dorsal fin, rounded flippers

• Fastest whale (30 mph)

• Social groups - pods

Delphinids: Dolphins & Porpoises

• Dolphins: have a beaklike snout

• Porpoises: have a rounded head

• Live in pods

• Known for intelligence & playful behavior

Splash !!