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 !!