Marine Mammals: Part 4 Marine Vertebrates: Lecture 10

Order Cetacea Suborder 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 Odontoceti Family Physeteridae, sperm whales Sperm Whale Artist unknown Distribution Physical characteristics  Head  Fins  Body size Spermaceti organ Feeding ecology Conservation  Most hunted whale Why so valuable?

Order Cetacea: Suborder Odontoceti Family Kogiidae, pygmy sperm whale Pygmy Sperm Whale T. 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 Odontoceti Family Monodontidae, narwhals and belugas Narwhal A. Martin Beluga U.S. Navy

Order Cetacea, Suborder Odontoceti Family 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 Odontoceti Family Delphinidae: dophins Bottlenose dolphin Photographer 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 Odontoceti Family Delphinidae: bottlenose dolphin Bottlenose dolphin Photographer unknown Distribution  Range: Worldwide,  Often in warm, shallow inshore waters  Associate in schools from  May travel long distiances No distinct migratory patterns Speeds up to 19 mph.

Order Cetacea: Suborder Odontoceti Family Delphinidae: bottlenose dolphin Bottlenose dolphin Photographer 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 Odontoceti Family 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 Odontoceti Family Delphinidae Spinner 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 Odontoceti Family Delphinidae Orca Photo: NOAA

Order Cetacea: Suborder Odontoceti Family Delphinidae Orca Photo: 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 Odontoceti Family Phocoenidae: porpoises Harbor porpoise Photo: 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 Odontoceti Family Zephiidae: Beaked whales Beaked whale Photo: Nan Hauser Overview  Teeth reduced or absent Examples… Feeding ecology  Squid! Conservation status  Most species are rare Strapped whales known only from strandings