190 likes | 756 Views
Marine Mammals. Order Cetacea & Sirenia Classification and Characteristics. Order Cetacea. Mysticeti (Baleen whales) Odontoceti (Toothed whales) Have made the most complete transition to aquatic life
E N D
Marine Mammals Order Cetacea & Sirenia Classification and Characteristics Order Cetacea & Sirenia
Order Cetacea • Mysticeti (Baleen whales) • Odontoceti (Toothed whales) • Have made the most complete transition to aquatic life • Have considerable morphological and ecological variability, but all share similar characteristics • Convergent evolution – different spp. develop similar structures due to a similar lifestyle Order Cetacea & Sirenia
Cetacea Characteristics • Elongated telescoped skull • Nostrils are on top of the head instead of in front, forming a single or double blowhole • Have a pair of front flippers, but the rear limbs have disappeared • Flukes are used for propulsion Order Cetacea & Sirenia
Suborder Mysticeti • Toothless or baleen whales, 11 spp. • Filter feeders which use baleen • Posses symmetrical dorsal skull with 2 blow holes • Are the largest whales and the largest animals that ever lived on earth Order Cetacea & Sirenia
The Roqurals • Includes: blue, fin, minke, and humpback • Feed by gulping large schools of krill or small fish • The lower part of the throat has grooves on the underside which distend when feeding Blue Whale Order Cetacea & Sirenia
The Right Whales • Includes: Bowhead and right whales • Swim at the surface with their mouths open Northern Right whale Order Cetacea & Sirenia
Mysticeti Feeding Types Order Cetacea & Sirenia
Suborder Odontoceti • Includes: Sperm whales, narwhals, beaked whales, oceanic dolphins, true porpoises, and river dolphins • Have teeth, adapted for a diet of squid, fish and other marine mammals • Dorsally asymmetrical skull with a single blow hole • More variable morphologically and ecologically Order Cetacea & Sirenia
Sperm Whale • Largest of the toothed Whales on earth (Physeter catodon) • Eat squid, especially from great depths • Squid beaks and other undigestibles accumulate in the gut creating ambergris Order Cetacea & Sirenia
Killer Whale • Orcinus orca is common in cold water, worldwide • Two distinct groups of killer whales • Piscivores • Marine mammal carnivores Order Cetacea & Sirenia
Dolphins & Porpoises • Dolphins • Falcate dorsal fin • Conical teeth • Distinct beak • Porpoises • Triangular dorsal fin • Spade shaped teeth • Lack a beak Order Cetacea & Sirenia
Order Sirenia • Inhabit shallow water and feed strictly on plants • Herbivores - digestive tract is similar to horses and elephants • Use a prehensile upper lip to feed • Occupy tropical and subtropical waters Order Cetacea & Sirenia
Is it the Rum, or are you beautiful? • Have been exploited for their meat (tastes like veal) and oil- rich blubber • Reproduce slowly 1 calf ever 3 years • Only four species remain, all close to extinction • Dugongs – 10 ft. and 930 lb. (East Africa to some pacific islands) • Manatees – 15 ft and 1,320 lb. Order Cetacea & Sirenia