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Marine Mammals. Kingdom Animalia Phylum Chordata Class Mammalia. General Characteristics. Endotherms: “warm-blooded” or able to maintain a constant temperature through their metabolism Viviparous: embryo receives nutrients and oxygen through the placenta (exceptions: platypus and akidna)
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Marine Mammals Kingdom Animalia Phylum Chordata Class Mammalia
General Characteristics • Endotherms: “warm-blooded” or able to maintain a constant temperature through their metabolism • Viviparous: embryo receives nutrients and oxygen through the placenta (exceptions: platypus and akidna) • Mammary glands: produce milk for newborn • Hair: at some point in their lives they have hair/fur. • Blubber: thick layer of fat to keep warm
Class Pinnipedia (Pinnipeds) • Seal, Sea Lions and Walruses • Predators: feed mostly on squid and fish • Bodies are streamlined and adapted for swimming • Paddle-shaped flippers • Related to dogs and cats
Seals • Family Phocidae: True Seals • Lack ear flaps (pinnae) • Fore-flippers are short and have claw on each of the fine digits • Hind-flippers cannot be rotated forward • Swim with powerful strokes of rear flippers • Use only fore-flippers on land
Harbor Seal Adults to left Juvenile below
Elephant Seal • Largest pinnipeds • 20 ft long • 4 tons
Sea Lions and Fur Seals • Eared seals= have pinnae • Long, hairless or only partially haired fore-flippers with splayed digits • Large hind flippers; can rotate beneath the body • Swim mostly with fore-flippers • Can sit on land with head and neck raised.
Walruses • Distinct pair of protruding tusks • Feeds mostly on bottom invertebrates, particularly clams • Stiff whiskers act as feelers • Tusks used in defense and anchor on to ice
Sea Otter • Order Carnivora • Smallest marine mammals • Weighs 60 to 80 lbs • Lacks a layer of blubber • Dense fur to keep warm • Need to eat 25-30% of weight per day • Eat urchins, abalone, mussles, crabs
Manatees and Dugongs • Order Sirenia • Relatives of the elephants • Also known as a sea cow • Herbivores • Prefer warm water
Manatee • 15 feet and 3,000 lbs • Grayish in color • Tail is broad and rounded • 3 species • Found in Florida, South America and West Africa
Dugong • 10 feet and 600 lbs • Tail resembles a whales • One species • Found in Australia
Order Cetacea • Order Cetacea Three suborders: Archaeoceti- “ancient whales”; all extinct Mysticeti- “mustached whales” Odontoceti- “toothed whales”
1. Suborder Mysticeti (Baleen Whales) • Filter feeders, eat plankton & small fish • Baleen plates- made from protein, comb/ strain plankton • Largest whales- 150 tons; heart the size of a compact car; Blue whale: 103 ft. • Two blowholes, create a v-shape
a. Family Balaenidae (Right Whales) • Slowly swim at the surface • Many (more than 200) relatively short baleen plates • No throat pleats • 4 species; N & S Right Whales, Pygmy, & Bowhead
b. Family Balaenopteridea (Rorguals) • Take in huge gulps of water • Many (more than 200) relatively short baleen plates • Many (32-100) long gular grooves: throat pleats • 6 species; Blue, Fin, Sei, Bryde’s, Minke, Humpback
c. Eschirichtiidae (Gray Whales) • Feed by scraping the bottom floor • Fewer baleen plates (130-180) • No dorsal fin; 6-12 prominent dorsal knuckles • One species; California Gray Whale
B. Suborder Odontoceti (Toothed Whales) • Peg-like teeth • Active hunters • More social than baleen whales
Family Physseteridae (Sperm Whales) • Spermaceti- white waxy material in head mistaken for sperm • Largest of the toothed whale; largest carnivore • No gular grooves • Dorsal fin or hump • Prey on squid: Whale from Moby Dick
2. Family Monodontidae (Narwhal and Beluga) • Melon- fatty tissue used in echolocation • 8-11 irregularly shaped teeth • No dorsal fin (to deal w/ sea ice or to preserve body heat) • Narwhal- long tusk thought to be used as a show of dominance in males
3. Family Ziphiidae (Beaked Whales) • Reversed sexual dimorphism- females are larger than males • Beak is similar to dolphins • 1-2 pairs of teeth in lower jaw • Feed on bottom of ocean floor • Longest dive-85 minutes