marine mammals: part 3 marine vertebrates: lecture 9
Post on 17-Dec-2015
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Cetacea OriginsArchaeocetes (~50 mya)
• Pakicetus Long, slender
jaws Simple teeth Dorsal blowhole Robust pelvis and
hindlimbs
Order CetaceaSuborder Mysticeti
Overview
•Baleen
•Head
•# of species
•Location/ feeding
Right whale baleen; photographer unknown
Order Cetacea: Suborder Mysticeti
Family 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
Order Cetacea: Suborder Mysticeti
Family Balaenidae: bowhead whale
Bowhead whale; artist unknown
• 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
Order Cetacea: Suborder MysticetiFamily Balaenidae: Southern right whale
Southern right whale: Photo: Ocean Alliance
• Callosities
•Why called right whales?
• Two species
• Current status
Callosity close-up: Whale lice and barnacles on a right
whale
Whale licePhoto: Vicki Roundtree
Photo: Iain Kerr Ocean Alliance
Order Cetacea: Suborder Mysticeti
Family Eschrictiidae: Gray whales
Gigi the Gray WhalePhoto: Ron Church
• 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
Order Cetacea: Suborder Mysticeti
Family Balaenopteridae
Humpback Whale,Photo: K. Haberman
• Throat grooves: expansion during feeding• Depressed frontal bones• Small, posterior dorsal fin; flipper size varies• Relatively fast
Order Cetacea: Suborder Mysticeti
Family Balaenopteridae: minke whale
Minke Whale, Project Atlantis
• Worldwide distribution• To whale or not to whale?• Antarctic populations feed on…krill!• Northern pops feed on krill & fish
Order Cetacea: Suborder MysticetiFamily Balaenopteridae: humpback whale
Humpback WhalePhoto: H-C travel
• 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
Order Cetacea: Suborder MysticetiFamily Balaenopteridae: blue whale
Blue WhalePhoto: Project Atlantis
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…???
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