Aquatic Flashcards
ursids
polar bear is apex of marine ecosystem
feed mainly on seals and walrus
most of life is spent on sea ice
mustelids
sea, river, and marine otters
belong to the weasel family and are carnivores
marine otter
lives along Pacific coast of South America
spends time in the ocean but lives on land
prefers rocky shores and kelp forests
sea otter
the only species that lives entire life in the ocean: grooming their fur creates air bubbles that help keep them buoyant and insulate them
marine otters
more closely related to the 3 species of American river otters than to sea otters which indicates that costal/marine lifestyle evolved twice in the weasel family
pinnipeds
seals, sea lions, walruses
have front and rear flippers
sea lions
“walk” on land using large flippers
have visible ear flaps
bark like dogs and are loud
California sea lions congregate in groups called rafts
seals
have small flippers
wriggle on their bellies on land
lack visible ear flaps
many varieties: Pacific harbor seal known for spotted fur; elephant seal has huge nose that looks like elephant trunk; fur seal is closely related to sea lion, have heavy fur, hunted for pelt, spend most time far from land
walrus
both females and males have tusks that grow with age and vacuum-like mouths for sucking up shellfish from the ocean floor
have air sacs in neck that can inflate to allow them to float
largest pinnipeds
sirenias
manatees and dugong “seacow”
aka sirens: where the mermaid legend came from
evolved from 4-legged land mammals: their flippers have vestigal toenails which is a remnant of the claws they had when they lived on land (Amazonian manatee doesn’t have)
manatees
have large egg-shaped head, flippers, and flat tail
aka sea cows because of their large stature, slow movements, and lolling nature, propensity to be eaten
closely related to elephants
swim alone or in pairs
in a group = mating herd or informal meeting sharing a warm area with large food supply
herbivores: prefer sea grasses
manatee anatomy
only have 6 neck vertebrae so can’t turn head sideways
algae and photosynthetic organisms often grow on their skin
can stay under water for 15 minutes without breathing
dugong
dugong dugon
similar to manatees
part of Sirenia order but different family: Dugongidae
have a notch in their tails and tusks
cetacea
whales, dolphins, and porpoises
split up into toothed and Baleen
toothed whales
sperm whales, killer whales, belugas, narwhals, porpoises, river dolphins
have single blowhole, teeth, and use echolocation
have a layer of fatty tissue under their skin called blubber which maintains body heat, and is an important energy source
very good eyesight
orcas
large dolphins
orcas and dolphins thought to be some of the smartest animals: very curious, exhibit complex social structures living in small groups for mating and often coordinated hunting
baleen whales
great whales: blue whale, right whales, minke whales, humpbacks
right and bowhead whales lack dorsal fin
they have double blowhole and upper jaw is hung with a baleen (stiff plates of keratin with fringes inside) instead of teeth
how do baleen whales feed?
by gulping large amounts of water and prey
when the whale brings its jaws together water is forced through the baleen fringes and out the sides of the mouth
baleen whales migration
most make long-range seasonal migrations and move toward polar feeding areas in the summer and toward low-latitude (tropical) calving areas in winter
juveniles and post-reproductive adults tend to stay in protected nearshore areas
beluga whales
small toothed whale that is brown-gray at birth and bright white in adulthood
only whale species that have a movable neck: can move up and down, side to side
narwhal whales
part of the “white whales” family
males have the characteristic tusk
ectothermic
cold blooded, influenced by the environment
teleost fish
bony fish found in salt and freshwater from the tropics to the Arctic and Antarctic, and from coasts to deepest parts of the ocean
teleost anatomy
scales are flat and covered by a thin layer of skin and mucus
fish breathe through gills which absorb dissolved oxygen in the water
water comes in through the mouth, passes over gills, and leaves out of operculum
have swim bladder filled with air for buoyancy
lateral line along spine = sensory organ that detects movement and vibration
vent: waste
2-chambered heart