marine mammals: part 4 marine vertebrates: lecture 10
TRANSCRIPT
Marine Mammals:Part 4
Marine Vertebrates: Lecture 10
Order CetaceaSuborder Odontoceti
• Teeth Simple teeth
• Single roots • conical crowns
Increase # of teeth (some)
Some with highly derived teeth or secondary loss of teeth • Example: sperm
whales
Scrimshaw; Robert Schoen
Pygmy sperm jaw; Arizona dry bones
Order Cetacea: Suborder OdontocetiFamily Physeteridae, sperm whales
Sperm WhaleArtist unknown
• Distribution
• Physical characteristics
Head Fins Body size
• Spermaceti organ
• Feeding ecology
• Conservation Most hunted whale
• Why so valuable?
Order Cetacea: Suborder OdontocetiFamily Kogiidae, pygmy sperm whale
Pygmy Sperm WhaleT. Komakko
• Similar head and oil as sperm whale• Not as large, and also not as elongate• Similar diet as sperm whales
Use of bioluminescent squid ink as defense!
Order Cetacea, Suborder OdontocetiFamily Monodontidae, narwhals and belugas
NarwhalA. Martin
BelugaU.S. Navy
Order Cetacea, Suborder OdontocetiFamily Monodontidae, narwhals and belugas• Distribution
Circumpolar, arctic only Migrations linked to advance and retreat
of the pack ice.
• Physical characteristics Small whales, up to ~5m Blunt head, small mouth, no dorsal fin,
small pectorals Narwhal’s tusk (♂) is a modified tooth; ♂ -
♂ competion
• Feeding ecology The two species have complementary
distributions and feeding behaviors
Order Cetacea: Suborder OdontocetiFamily Delphinidae: dophins
Bottlenose dolphinPhotographer unknown
• Most diverse group of Cetacea
33 species
• Primarily fish and squid eaters, but…
• Teeth• Fins• Pointed beak (in
some)• Elaborate social
systems
Order Cetacea: Suborder OdontocetiFamily Delphinidae: bottlenose dolphin
Bottlenose dolphinPhotographer unknown
• Distribution Range: Worldwide, Often in warm,
shallow inshore waters
Associate in schools from 10-500
May travel long distiances• No distinct migratory
patterns
• Speeds up to 19 mph.
Order Cetacea: Suborder OdontocetiFamily Delphinidae: bottlenose dolphin
Bottlenose dolphinPhotographer unknown
• Feeding ecology How do they find food? What do they eat?
• Other distinctive behaviors
Hold young and injured at surface to breathe• May increase deaths in
nets
• Conservation status Classified as
“threatened” by IUCN
Order Cetacea: Suborder OdontocetiFamily Delphinidae: Pacific white-sided dolphin
Pacific white-sided dolphin Photo: Peggy Stap
• North Pacific• Nocturnal feeders: squid and fish• Large pods (100 or more)
Spinner dolphin Photo: Andre Seale
Photographer unknown
Order Cetacea: Suborder OdontocetiFamily DelphinidaeSpinner dolphin• Worldwide, tropical
and subtropical local “races”
• Found among schools of yellowfin tuna
• Spinning behavior Communication to
help aggregate? Parasite or remora
removal?
Tuna-dolphin issue
•Dolphin-safe?
Order Cetacea: Suborder OdontocetiFamily Delphinidae
OrcaPhoto: NOAA
Order Cetacea: Suborder OdontocetiFamily Delphinidae
OrcaPhoto: NOAA
• Distribution: Worldwide
• Pods/group size
• Physical characteristics
Teeth Dorsal fin
• Feeding ecology
• Conservation status Local Puget Sound pod
= endangered Captivity issue
Order Cetacea: Suborder OdontocetiFamily Phocoenidae: porpoises
Harbor porpoisePhoto: Riverhead Foundation
• Compare w/Delphinidae
Spade-shaped teeth Triangular dorsal fin No pointed beak Small compared to
delphinids
• Focus: harbor porpoise Distribution: Northern
Hemisphere, temperate to subarctic waters
Common, but rarely seen on surface
Diet• A variety of fishes• calves will eat…krill!
Order Cetacea: Suborder OdontocetiFamily Zephiidae: Beaked whales
Beaked whalePhoto: Nan Hauser
• Overview Teeth reduced
or absent• Examples…
• Feeding ecology Squid!
• Conservation status
Most species are rare• Strapped whales
known only from strandings