Marine Mammals: Cetaceans, Pinnipeds, Sirenians, Sea Otters, Polar Bears

This set of flashcards covers key vocabulary and concepts related to marine mammals, focusing on characteristics, classifications, and ecological roles.

CETACEANS

Fully aquatic mammals including whales, dolphins, and porpoises.

Core traits of Cetaceans

Never come on land, forelimbs as flippers, horizontal tail flukes, thick blubber, and no external ears.

Baleen Whales (Mysticeti)

Filter feeders characterized by baleen plates used to trap food.

Odontoceti

Toothed whales that use echolocation and engage in active predation.

Echolocation

A method used by toothed whales to navigate and hunt by producing clicks.

Phocidae

True seals, known for not having external ear flaps and moving awkwardly on land.

Otariidae

Sea lions and fur seals, distinguished by external ear flaps and ability to rotate hind flippers.

Odobenidae

Walrus family, the only living member known for huge tusks and specialized feeding.

SIRENIANS

Order of fully aquatic herbivorous mammals, including manatees and dugongs.

Manatees

Sirenian family Trichechidae, which includes freshwater and marine species.

Dugongs

Sirenian family Dugongidae, known for strictly marine habitats.

Sea Otters

Least aquatic marine mammals, known for dense fur and tool use.

Polar Bears

Semi-marine carnivorous mammals dependent on sea ice for hunting.

Thick Blubber

Insulation and energy storage found in many marine mammals.

Benthic Feeder

An organism that feeds off the sea floor, such as the gray whale.

Convergent Evolution

The phenomenon where unrelated species develop similar traits due to similar environments.

Keystone Species

A species that has a disproportionately large effect on its environment, such as sea otters.

Apex Predator

A predator at the top of its food chain, like the killer whale.

Diagnostic Fossil Trait

A specific characteristic in fossils, such as the double-pulley astragalus in cetaceans.

Status of Pinnipeds

Semi-aquatic, coming on land or ice for birth, mating, and molting.

Geographic Rule for Polar Bears

Only found in the Northern Hemisphere, with no overlap with penguins.