Marine Mammals: Part 3

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Marine MammalsPart 3

• Marine Vertebrates Lecture 9

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Cetacea OriginsArchaeocetes (50 mya)

• Pakicetus
• Long, slender jaws
• Simple teeth
• Dorsal blowhole
• Robust pelvis and hindlimbs

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Cetacea OriginsArchaeocetes (50 mya)

• Basilosaurus
• More obviously aquatic
• Reduced hindlimbs

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Order CetaceaSuborder MysticetiOverview

• Baleen
• Head
• of species
• Location/ feeding

Right whale baleen photographer unknown
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Order Cetacea Suborder MysticetiFamily
Balaenidae

• Large heads
• Bowed (highly curved) mouth
• Adaptive value?
• Characteristics of baleen?
• Fins
• No dorsal
• Small pectoral fins
• Primarily known to feed on copepods
• Feed by skimming

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Order Cetacea Suborder MysticetiFamily
Balaenidae bowhead whale

• Arctic
• Follows cycle of ice
• Most northerly Mysticeti
• Hunting began 1600, near extinction by 1900
• Slow recovery
• Inuit hunting
• Head may be up to 40 of body length
• Baleen highly valued
• Silky and Long

Bowhead whale artist unknown
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Order Cetacea Suborder MysticetiFamily
Balaenidae Southern right whale

• Callosities
• Why called right whales?
• Two species
• Current status

Southern right whale Photo Ocean Alliance
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Callosity close-up Whale lice and barnacles on
a right whale
Photo Iain Kerr Ocean Alliance
Whale lice Photo Vicki Roundtree
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Order Cetacea Suborder MysticetiFamily
Eschrictiidae Gray whales

• Where found?
• Key Features
• Relatively slender
• Whale lice/barnacles
• Throat grooves (2-7)
• Bottom feeders
• Method? Key food?
• Migration
• Once near extinction
• Recovery
• Removed from U.S. endangered species list in 1994

Gigi the Gray Whale Photo Ron Church
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Order Cetacea Suborder MysticetiFamily
Balaenopteridae

• Throat grooves expansion during feeding
• Depressed frontal bones
• Small, posterior dorsal fin flipper size varies
• Relatively fast

Humpback Whale,Photo K. Haberman
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Order Cetacea Suborder MysticetiFamily
Balaenopteridae minke whale

• Worldwide distribution
• To whale or not to whale?
• Antarctic populations feed onkrill!
• Northern pops feed on krill fish

Minke Whale, Project Atlantis
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Order Cetacea Suborder MysticetiFamily
Balaenopteridae humpback whale

• Worldwide distribution
• Migrate cold water (feed) to tropics (breed)
• Feed on krill and fish
• Huge pectoral fins
• Distinctive white patches
• Scars, barnacles and cookie-cutter bites
• Distinctive behaviors
• Conservation status vulnerable
• Hunted by Carib natives

Humpback Whale Photo H-C travel
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Whale songs

• How produced?
• Which ones sing?
• Singing posture
• Song length
• Changes over time

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Order Cetacea Suborder MysticetiFamily
Balaenopteridae blue whale
Blue Whale Photo Project Atlantis
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Blue whale facts

• Distribution Once worldwide now largest
  populations are off coast of _____?
• Migrate to tropical waters for calving
• In some tropical areas, blue whales are seen year
  round
• Why might this be?
• Largest animal ever
• Up to 24.5 meters (female) Mouth alone of 6
  meters 190 tons
• Heart the size of a VW bug
• Spray from blow is about 6 meters high.
• Larger prior to mechanized whaling
• Only hunted after the development of the grenade
  harpoon (1800s)
• In one year, 30,000 were killed (not sure which
  year)
• Loudest,deepest voice of any animal 180 dB, 10
  Hz
• Diet is almost exclusively???