Download Invertebrate Zoology Lecture 2, March 31, 1999

Marine Biology, June 9, 2006
Lecture 19: Antarctic Birds and Mammals
I.
II.
III.
IV.
Non-penguin seabirds: many species, including…
A.
Blackbrowed albatross (and other albatross species)
B.
Southern giant petrel
C.
Wilson’s storm petrels
D.
Blue-eyed shags
E.
NOTE: Many others; birds are highly successful in the Southern Ocean!
Order Pinnipedia: Seals, sea lions and walruses (but no walruses in the Antarctic)
A.
Family Phocidae: true (earless) seals
1.
Phocid characteristics
a.
no external ear
b.
short foreflippers
c.
hindlimbs held parallel, work together for propulsion
d.
relatively short neck
e.
Sex organs retractable; testes internal
f.
Best divers are in this group (Elephant seals: deepest pinniped divers)
2.
Antarctic species
a.
Crabeater seal
b.
Elephant seal
c.
Leopard seal
d.
Weddell seal
e.
Ross Seal (relatively rare)
B. Family Otariidae: sea lions, fur seals
1.
Otariid characteristics
a.
small external ear
b.
long foreflippers used for standing (on land), and for propulsion
c.
hindlimbs can be splayed apart, turned under body for support on land
d.
Sex organs retractable; testes external
e.
Flexible neck: predation
f.
Porpoising behavior (not generally seen in the Phocidae)
2.
Antarctic species
a.
Antarctic fur seal; Subantarctic fur seal
C. Family Odobenidae: walruses: 1 species, circumpolar (N. Pacific and N. Atlantic subspecies; no
Antarctic species)
1.
No Antarctic species, so won’t go into…
Order Cetacea
A.
Suborder Mysticeti: the baleen whales
1.
Major characteristics
a.
Baleen plates for filter-feeding
2.
Key species
a.
Humpback whales
b.
Minke whales
Suborder Odontoceti: toothed whales
A.
Antarctic species = Orcas!
Study questions:
1.
Compare the characteristics of Family Phocidae vs. Family Otariidae within the Order Pinnipedia.
To which of these Families do most Antarctic pinnipeds belong?
2.
Be able to name several mammal and bird species that feed on…krill! Name others that do not
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eat the krill, but rely on them indirectly (perhaps via other food web links).
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