Marine mammals Characteristics of marine mammals Warmblooded Breathe

Marine mammals Characteristics of marine mammals: Warm-blooded Breathe air Have hair (or fur) Bear live young Females have mammary glands that produce milk for their young

Marine mammals: Order Carnivora All members of order Carnivora have prominent canine teeth Includes: Sea otters Polar bears Pinnipeds (flipper-footed) Walrus Seals Sea lions/fur seals California sea lions Figure 14 -17 c

Differences between seals and sea lions/fur seals Seals: Lack ear flaps Have small front flippers Have claws Cannot rotate hind flippers beneath themselves Figure 14 -18

Marine mammals: Order Sirenian characteristics: Large body size Sparse hair all over body Vegetarians Toenails (on manatees only) Includes: Manatees Dugongs

Marine mammals: Order Cetacean characteristics: Blowholes on top of skull Skull telescoped (streamlined shape) Very few hairs Includes: Whales, dolphins, and porpoises

Marine mammals: Order Cetacea Figure 14 -20

Two suborders of order Cetacea Suborder Odontoceti (toothed whales) Echolocate (send sound through water) Includes killer whale, sperm whale, dolphins, porpoises, and many others Suborder Mysticeti (baleen whales) Have rows of baleen plates instead of teeth Includes blue whale, finback whale, humpback whale, gray whale, and many others

Differences between dolphins and porpoises Dolphins have: An elongated snout (rostrum) A sickle-shaped (falcate) dorsal fin Teeth that end in points Killer whale jawbone Figure 14 -22

Generation of Odontoceti echolocation clicks Figure 14 -23

Odontoceti echolocation Sound is bounced off objects to determine: Size Shape Distance Internal structure Figure 14 -24

Mysticeti: The baleen whales Mysticeti whales have baleen instead of teeth Baleen plates: Hang as parallel rows from the upper jaw Are made of keratin Are used as a strainer to capture zooplankton Allows baleen whales to eat krill and small fish by the ton

Baleen Figure 14 -25

BALEEN

Types of baleen whales Baleen whales include three families: Gray whale (a bottom-feeder with short baleen) Rorqual whales (medium-sized baleen) Balaenopterids (blue whales, finback whales, and other large whales ) Megapterids (humpback whales) Right whales (surface skimmers with long baleen)

An example of migration: Gray whales undertake the longest annual migration of any mammal: Spend wintertime in birthing and breeding lagoons in Mexico Spend summertime feeding in highly productive Arctic waters Figure 14 -27