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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
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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 14-17c
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 Sirenia • Sirenian characteristics: • Large body size • Sparse hair all over body • Vegetarians • Toenails (on manatees only) • Includes: • Manatees • Dugongs
Marine mammals: Order Cetacea • 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
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 • 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