Order Cetacea & Sirenia Classification and Characteristics 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 Porpoises 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