LEC 12 - MARINE MAMMALS I (DIVERSITY) Flashcards
what are four traits of marine mammals?
- warm blooded
- air breathing
- fur/hair
-live young that suckle milk
what do the marine carnivora include? (5 groups)
how are they characterized from other marine mammals?
sea otters, seal lions, walruses, true seals, eared seals
notable traits incl prominent canine teeth for eating meat, live locally but are fast swimmers, live close to shore and breed on land
how do sea otters differ from river otters? what else do they do thats kinda fun
are adapted to live in water (dive to feed on shellfish and crustaceans)
use tools like rocks to break open shells, and store food in skin flaps that act like grocery bags
how do sea otters keep warm? (2 things to consider)
blow bubbles into their fur, and since air holds heat really well they stay insulated
they also gotta eat 25% body weight daily to keep metabolism up
what is a keystone species? how are otters keystone species?
keystone species are those whose presence affects the ecosystem itself
otters eat urchins, who graze on kelp. when otters are not present in an environment, urchins completely raze down kelp forests, leaving behind urchin barrens. the predation of otters over urchins maintains the kelp forest, making otters keystone species.
what are the tusks of walruses used for?
how do walruses find clams and other subterranean prey?
how do walruses keep warm?
walrus males use tusks to spar
use extremely sensitive whiskers to ascertain where clams and other prey are
keep warm w hella blubber
what are the tusks of walruses used for?
how do walruses find clams and other subterranean prey?
how do walruses keep warm?
walrus males use tusks to spar
walruses use extremely sensitive whiskers to ascertain where clams and other prey are
walruses stay warm w lots of blubber
how do phocids and otarids differ on:
- ears
- land/water adaptation
- positioning of legs
- foraging area
- sociality
phocids are true seals, otarids are eared seals (otarid and ear both start w vowels)
- P dont have ears, O do
- P are adapted for water, O are adapted for land
- P legs are flippers, O legs are positioned below the body for running
- P are deep divers, O are shallow water scavengers
- P are indep, O are social
how are the manatees doing?
not great :(
- large, solitary mammals
- eat sea grass (which is getting reduced by climate change)
- low fecundity, rear young for a long time (like most mammals)
what is the diff bw baleen whales and toothed whales?
baleen whales have baleen over mouths which they use to filter feed, toothed whales have teeth
what group is the fastest swimmer (carnivora, sirenians, cetaceans)
cetaceans (dolphins + rorquals go brazy)
what is the purpose of cetaceans producing ethylene oxide droplets?
sheds the skin –> reduces drag
what is ambergris?
expensive product found in perfume, produced sperm whales (either from shidding or throwing up)
what features distinguish cetaceans? (3)
streamlined bodies, forelimbs modified to flippers for everyone in the family, specialized inner ears for communication
what is sieving? what are the three methods that employ sieving?
sieving is another word for filter feeding
- skim feeders, who float on the surface (due to high blubber content) and eat microorganisms that live near the top of the water column
- bulldozers, who eat dirt and filter out the sediment to eat the dudes who live in it
- lunge feeders, who do the crazy jaws move and eat plankton in the process
