Marine Mammals: Part 4

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Marine MammalsPart 4

• Marine Vertebrates Lecture 10

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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
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Order Cetacea Suborder OdontocetiFamily
Physeteridae, sperm whales

• Distribution
• Physical characteristics
• Head
• Fins
• Body size
• Spermaceti organ
• Feeding ecology
• Conservation
• Most hunted whale
• Why so valuable?

Sperm Whale Artist unknown
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Order Cetacea Suborder OdontocetiFamily
Kogiidae, pygmy sperm whale

• 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!

Pygmy Sperm Whale T. Komakko
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Order Cetacea, Suborder OdontocetiFamily
Monodontidae, narwhals and belugas
Narwhal A. Martin
Beluga U.S. Navy
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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
• Narwhals tusk (?) is a modified tooth ? - ?
  competion
• Feeding ecology
• The two species have complementary distributions
  and feeding behaviors

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Order Cetacea Suborder OdontocetiFamily
Delphinidae dophins

• Most diverse group of Cetacea
• 33 species
• Primarily fish and squid eaters, but
• Teeth
• Fins
• Pointed beak (in some)
• Elaborate social systems

Bottlenose dolphin Photographer unknown
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Order Cetacea Suborder OdontocetiFamily
Delphinidae bottlenose dolphin

• 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.

Bottlenose dolphin Photographer unknown
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Order Cetacea Suborder OdontocetiFamily
Delphinidae bottlenose dolphin

• 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

Bottlenose dolphin Photographer unknown
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Order Cetacea Suborder OdontocetiFamily
Delphinidae Pacific white-sided dolphin

• North Pacific
• Nocturnal feeders squid and fish
• Large pods (100 or more)

Pacific white-sided dolphin Photo Peggy Stap
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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?

Spinner dolphin Photo Andre Seale
Photographer unknown
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Tuna-dolphin issue

• Dolphin-safe?

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Order Cetacea Suborder OdontocetiFamily
Delphinidae
Orca Photo NOAA
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Order Cetacea Suborder OdontocetiFamily
Delphinidae

• Distribution Worldwide
• Pods/group size
• Physical characteristics
• Teeth
• Dorsal fin
• Feeding ecology
• Conservation status
• Local Puget Sound pod endangered
• Captivity issue

Orca Photo NOAA
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Order Cetacea Suborder OdontocetiFamily
Phocoenidae porpoises

• 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 eatkrill!

Harbor porpoise Photo Riverhead Foundation
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Order Cetacea Suborder OdontocetiFamily
Zephiidae Beaked whales

• Overview
• Teeth reduced or absent
• Examples
• Feeding ecology
• Squid!
• Conservation status
• Most species are rare
• Strapped whales known only from strandings

Beaked whale Photo Nan Hauser