MSCI 210 Lecture Notes - Lecture 17: Dugong, Blubber, Canine Tooth
Document Summary
Return to the oceans: mammals have returned to the ocean multiple times. Adaptations: vivipary, suckling young, thermo regulation, feeding, diving, osmoregulation. Two basic bioenergetic strategies used by animals: endothermy: warm blooded, ectothermy: cold blooded. Counter current exchange: view slide 6 for final, how mammals gain or get rid of heat. Marine birds: salt excretion in birds, has a nostril that secretes salt near its nose, uses same countercurrent exchange, penguins. Glands that produce milk for their young: marine mammals: order sirenia. Most complete transition to marine life along with whales and dolphins. Nostrils have valves to keep water out. Both species have one calf at a time. 1 calf every three years: manatee. Marine mammals: carnivores: all members have prominent canine teeth. Walrus, seals, sea lions: sea otter. Diet: sea urchins, mussels, crabs, can use tools: polar bears. Hunt seals and walruses, occasionally whales: pinipeds. 34 known species, differ in mode of locomotion: differences in seal and sea lions.
