Mammals Mammals Mammalian Characteristics Mammalian Diversity

Bumblebee bat Class Mammalia

 Order Carnivora – Suborder Pinnipedia

 Family Otariidae

 Family Phocidae

 Order Cetacea – Whales, dolphins and porpoises Pinnipeds

 Characteristics: – Must come to land/ice to breed

 Pagophilic – Feed on fish and squid – Most large in size – Residents of cold water – Enhanced diving ability Family Otariidae

 ‘Eared Seals’ Family Otariidae

 Steller Sea Lion – Eumetopias jubatus Family Phocidae

 ‘True Seals’

Order Cetacea

 Suborder Odontoceti – Family Physeteridae (sperm whales) – Family Delphinidae (dolphins) – Family Phocoenidae (porpoises)

 Suborder Mysticeti – Family Balaenidae (right whales) – Family Balaenopteridae (rorquals) Odontoceti

 Toothed Whales – Single blowhole – Sexual dimorphism – Echolocation Family Physeteridae

 Sperm whale (Physeter macrocephalus)

• Squared head • 36-50 conical teeth in lower jaw • Low dorsal hump • Off-center blowhole Spermaceti Organ Essex Family Delphinidae

 Killer Whale (Orcinus orca)

• Distinct coloration • Prominent dorsal fin • 20-26 teeth in upper and lower jaws • Fast swimmers Family Delphinidae

 Atl. Bottlenosed Dolphin (Tursiops truncatus)

• Well-defined beak • Lack patterns • Blue-gray to brown • Coastal and offshore forms Echolocation  1500 m/sec

 Object is 3 sec away

 4500 m away

Mysticetes

 Baleen whales – Divided blowhole – Differences in size between sexes – No echolocation Family Balaenidae

 Northern Right Whale (Balaena glacialis)

• Narrow, arching rostrum • No dorsal fin • V-shaped blow • No throat grooves Family Balaenopteridae

 Humpback Whale (Megaptera novaeangliae)

• Flat, broad head • Long flippers • Small dorsal fin with hump • Ventral throat grooves Mysticeti Feeding Types Swimming

 Streamlined bodies Breathing

 Quick breaths – Can empty and re-fill lungs in 2 seconds!!!  Renew ~90% of air in single breath – Humans ~10%

Diving Physiology  More blood than non-diving mammals – More hemoglobin – More myoglobin Dive Reflex

 Heart rate slows – Bradycardia  Blood flow reduced – Vasoconstriction  Increase in lactic acid The Bends  Decompression Sickness

– N2