Marine mammals Maximum 7 Suborder breath-hold Order 1 or Family Common name Limbs and Locomotion Lifestyle / location (minutes) so. Mysticeti Baleen whales Completely aquatic, 80 Cetacea Forelimbs as flippers; Bowhead whale Various families Toothed whales hindlimbs vestigial only; including blue-water ocean; (relatives of some migrate from tropics 138 hippopotami) Delphinidae Dolphins 2 tail drives locomotion Sperm whale to polar oceans suborder 12 Odontoceti Phocoenidae Porpoises B'nose dolphin Completely aquatic (estuarine Sirenia Trichechidae Manatees Paddle-like forelimbs; 50 Ma (relatives of to coastal); consume macro- 16 elephants hindlimbs residual only; scopic plants and thus the West Indian and hyrax) Dugongidae Dugongs tail drives locomotion manatee Completely aquaticorders only vegetarians here 3,4 120 True seals or Swim by side-to-side Spend most of their time at female ele- Phocidae earless seals sinuosity with hindflippers, sea and migrate considerable phant seal (nineteen modern which are fused to pelvis so distances; wriggle onto ice or 82 species) that walking is impossible land to give birth and nurse. Weddell seal 4 Walruses Swim by sinuosity, Long tusks; no external ears. but can turn hind flippers Odobenidae (one species) Lives in Arctic, with long 13 to move on all fours migrations; can move on ice Mammalswith no external ear structure andswim that by flexing body and/or tail Largely terrestrial order Carnivora 3,4,5 (cat-like Hindlimbs can be turned Small external ears; (feliform) Fur seals Eared 15 Otariidae forward to allow move- spend more time out California and dog-like superfamily Pinnipedia Sea lions seals ment on all fours of water than true seals sea lion (caniform) Completely aquaticfamilies mammals – all at Legs and paws; swimming mostly Live along shorelines; 6 right are Mustelidae driven by back feet. Sea otter is only sometime break open caniform) (weasels, martens, Sea otters 4 badgers, otters) Marine otters marine mammal to catch fish with molluscs with rocks Sea otter forepaws rather than mouth and thus use tools swim using limbs Limbs are legs for walking, but Terrestrial ear structures and that Ursidae Polar bears with disproportionately large feet; and on ice Mammalswith external (bears) can run at 25 mph and in Arctic; largely < 2 can dog-paddle swim ≥ 100 km Largely terrestrial families eat true seals Notes: Sources: 1 In addition to these extant marine mammals are the mammals have other typically-protruding structures various Wikipedia pages; J.L. Sumich & J.F. extinct Oligocene-Miocene order Desmostylia and recessed in their bodies. Morrisey (2004) Introduction to the Biology of Miocene-Pliocene genus Thalassocnus (of the order 5 DNA studies have shown that the distinction between fur Marine Life (8th edn.); J.F. Schreer & K.M. Kovacs Pilosa, the sloths and anteaters), both of which were seals and sea lions has no phylogenetic significance. (1997) Allometry of diving capacity in air-breathing nearshore plant-eaters. 6 Sea otters are the only marine Carnivorans that can give vertbrates: Canadian Journal of Zoology, v. 75, p. 2 The Delphinidae include Orcas (killer whales) but not birth in the water. 339-358, and the IUCN/SSC Polar Bear Specialist river dolphins. 7 The breath-hold data shown are not necessarily maxima Group webpage at pbsg.npolar.no/en/faq.html. 3 “Seals” include members of two different families. for the entire family but only for the species shown. 4 External ears increase hydrodynamic drag and so are Caveat emptor: This table was prepared by a geology lost in more adapted marine mammals; many such professor for his elementary oceanography class. LBR 3030MarineMammalsTable3 4/2011.