Marine Mammals: Part 4

1. Marine Mammals:Part 4 Marine Vertebrates: Lecture 10

2. 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

3. 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

4. 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

5. Order Cetacea, Suborder OdontocetiFamily Monodontidae, narwhals and belugas Narwhal A. Martin Beluga U.S. Navy

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. Tuna-dolphin issue • Dolphin-safe?

13. Order Cetacea: Suborder OdontocetiFamily Delphinidae Orca Photo: NOAA

14. 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

15. 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 eat…krill! Harbor porpoise Photo: Riverhead Foundation

16. 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