Post on 09-Feb-2016
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Marine Reptiles, Birds, Mammals
Ancestors of these various animals re-invaded oceans after evolving adaptations to life on land.
They had to make a transition back to the oceanFour limbs two limbs (flippers)Lungs lungs with modification to store
oxygenDryer habitat water - adaptations to
osmoregulation
Marine Reptiles, Birds, Mammals – Fig. 9-1
Internal fertilization – External Development (ovoviviparous)
Leathery shells decrease water lossScales/dry skin – decreases water lossUric acid as a nitrogenous waste decreases
water lossEctotherm/poikilotherm
Marine Reptiles
Sea Turtles
Carapace – shell fused to backboneLegs modified into finsCan not retract head (land turtles can)Usually only leave water every 2-4 years to
lay eggs (mating occurs at sea)Females return to beaches from which they
were bornMigrate – navigate by wave motion &
magnetic field of earth100-160 eggs laid in sand to incubate for 60
days (Fig. 9-2)All nine species are endangered
Sea Turtles
http://www.arkive.org/loggerhead-turtle/caretta-caretta/video-09b.html (loggerhead turtle laying eggs)
http://www.youtube.com/watch?v=TYX0Kt73li8&NR=1 (turtle covering nest)
http://www.youtube.com/watch?v=fH9nNDdFh4w&feature=related (turtle heading back to sea)
http://www.youtube.com/watch?v=0TbzP0AT1Bk (sea turtles hatching)
http://www.youtube.com/watch?v=j9olIycYg0c (TED)
Sea Turtles
Totally marine
Most venomous but usually not aggressive
carnivores
Sea Snakes – Fig. 9-4
http://www.metacafe.com/watch/6192859/trending_topics_with_matt_zaller_episode_6/?source=playlist (sea snake)
http://www.youtube.com/watch?v=Xf240LcsPno (eagle catching sea snake)
Sea Snakes – Fig. 9-4
Marine iguana – Galapagos Island – Fig. 9-5Saltwater crocodile
Other Marine Reptiles
Live a large part of their life at seaFeathers – aid in warmth & buoyancy , water
proofEndotherms/homeothermicNest on landWebbed feet
Seabirds
Wings modified to flippers/can not flyHeavier bones decrease buoyancyStreamlined bodiesExcept for Galapagos, all live in cold climatesFat decreases heat lossEggs laid in winter in order to hatch during
spring when prey is abundantParental responsibilities are shared
Penguins – Fig. 9-6a
Penguins
Penguins
http://www.youtube.com/watch?v=r3RElQWsh34 (emperor penguin & leopard seal)
Penguins
Tubelike nostrils/heavy bills – curved Fig. 9-7a
Spend extended period of time at seaGreat flyersSalt glands to excrete excess salt
Turbernoses
Turbernoses
Webbing between all four toes
Pelicans
Largest variety of seabirds
Gulls and Related Birds
Do not swimFound along beaches and estuaries
Shorebirds
Viviparous – placentaEndotherm; homeothermicHair, mammary glands produce milkLarger brain than other vertebratesDo not give birth to a large number of young
because a lot of parental involvementMarine mammals followed different
evolutionary paths and adapted to the marine environment in different ways.
Marine Mammals
Evolved from terrestrial carnivorePaddle-shaped flippers for swimmingBreed and give birth on landBlubber – insulates, serves a food reserve and aids
in buoyancy (large body size also serves to decrease heat loss because of a decrease in the surface area to volume ratio)
Seals – rear flippers can not move forward, have internal ears
Sea lions – rear flippers can move forward, have external ears; front flippers can be rotated backward for support
Walrus - tusks
Seals, Sea Lions, WalrusesOrder Pinnipedia
Seals, Sea Lions, WalrusesOrder Pinnipedia
Seals, Sea Lions, WalrusesOrder Pinnipedia
Seals, Sea Lions, WalrusesOrder Pinnipedia
http://video.nationalgeographic.com/video/player/animals/mammals-animals/seals-and-manatees/walrus_cuddle.html (walrus mother and pup)
http://www.youtube.com/watch?v=9PKDbJ-0gzs (monk seal)
Seals, Sea Lions, WalrusesOrder Pinnipedia
Smallest marine mammal
Lacks blubber; insulates by air trapped in dense fur
Most of its time is spent in water including breeding & birth
http://www.arkive.org/sea-otter/enhydra-lutris/video-ne08a.html
Sea OttersOrder Carnivora
One pair of front flippers but no rear flippersHorizontal tailStrict herbivoresOne pup is born every 3 years
Manatees & Dugongs – “Sea Cows”Order - Sirenia
Manatees & Dugongs – “Sea Cows”Order - Sirenia
Manatees & Dugongs – “Sea Cows”Order - Sirenia
http://video.nationalgeographic.com/video/player/animals/mammals-animals/seals-and-manatees/dugong.html (dugong)
Whales/Dolphins/PorpoisesOrder Cetacea
Largest group of marine mammalsSpend entire life at seaConvergent evolution – different species develop similar
characteristics because of environmental pressures. This is achieved through natural selection
Paired anterior fins (posterior present in embryo only)Flukes – tailBlubberBaleen – fibrous plates that filters food from the waterBaleen whales have two blowholesToothed whales swallow food whole; have only one
blowhole
Whales/Dolphins/PorpoisesOrder Cetacea
Sperm Whale - toothed
Whales/Dol phins/PorpoisesOrder Cetacea
Humpback Whale(filter feeder)
Whales/Dolphins/PorpoisesOrder Cetacea
Blue Whale – filter feeder; largest animal
Whales/Dolphins/PorpoisesOrder Cetacea
Whales/Dolphins/PorpoisesOrder Cetacea
Whales/Dolphins/PorpoisesOrder Cetacea
Differences between dolphins and porpoises Porpoises have flattened, spade-shaped teeth.Another difference between these two similar
creatures is their lengths. Dolphins have an extremely wide range of lengths and widths, anywhere from 1.2 meters (4 ft) and 40 kilograms 88 pounds up to 9.5 meters (30 ft) and ten tons, referring to the killer whale. While the stubbly porpoise’s average length is just over 5 ft (1.5m) while females are slightly larger with average lengths of 5.5 ft (1.7m).
Whales/Dolphins/PorpoisesOrder Cetacea
Finally the most visible and easily spotted difference between these two mammals, their physical make up, the dolphins posses conical teeth and shorter beaks, while the porpoises generally tend to have flattened, spade shape teeth, the name porpoise in actuality was named from medieval times, porcopiscus (porcus pig + piscus fish).
http://library.thinkquest.org/J0110164/Life%20of%20the%20dolphin/dolphinvsporpoise.htm (dolphin vs porpoise)
Whales/Dolphins/PorpoisesOrder Cetacea
http://video.nationalgeographic.com/video/player/animals/mammals-animals/whales/whale_sperm.html (sperm whale diving)
http://arkive.org/blue-whale/balaenoptera-musculus/video-08.html (blue whale feeding)
http://www.youtube.com/watch?v=vJvfjiCTvq4 (humpback whales feeding)
http://www.youtube.com/watch?v=7-oL_MINZyo&feature=related (spinner dolphin)
Biology of Marine MammalsSwimming and Diving
Streamlined bodies a mustCetaceans move in an up and down motionAll other marine mammals paddle
Take quick breaths to avoid inhaling water (Cetaceans have blowhole on top to prevent this; can eat and breath at the same time)
Biology of Marine MammalsSwimming and Diving
Deep divers must be able to hold breath for extended period of time 90 % of O2 is exchanged during each breath (only
10-20% in humans)Have more blood with higher concentration of
RBC’s, therefore can carry more O2Muscles rich in protein myoglobin (stores O2)Reduce O2 consumption by slowing heart rate;
reducing blood flow to extremities & gutAdaptations to prevent N2 from dissolving in
blood; Lungs collapse & air is squeezed out – air is moved to central spaces where little nitrogen is absorbed
Biology of Marine MammalsEcholocation
Echolocation is the ability to sense surrounding by analyzing the reflection of sound waves, or “clicks”. Used to find prey and orientation
Clicks produced by pushing air through nasal passages
Clicks focused and directed into a beam by melon (fatty structure found in toothed whales)
Clicks are reflected back & received by lower jawSound transmitted to inner earElectrical stimulus is sent to brain & interpreted
(forms a mental image)http://www.youtube.com/watch?v=ZoNDW0zSRN
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Biology of Marine MammalsBehavior
Behavior – What an animal does and how it does it; results from both genes and environmental factors. Mammals exhibit more complex behaviors in which learning dominates over instinct
Biology of Marine MammalsBehavior
Vocal Communications – barks, grunts, whistles – species specificMaintain territoriesRecognize young or one anotherCetacean vocalization uses different types of
sounds than echolocationReflect moodSexual signalingMaintain distance between individualsWarning http://www.youtube.com/watch?v=v8b_I5IjNE4
Biology of Marine MammalsBehavior
Posture/Movement CommunicationsIndicate mood – Ex. Dolphins will open their mouth
as a threat postureTail slapping may be a warning signalhttp://www.youtube.com/watch?v=vv2VjaOK2iAPlay behavior – “just for fun” activities with no
apparent goals Dolphins will play with floating objects, “bow” ride
Breaching – warning signal; scanning surface; get rid of external parasites or maybe just for fun
Spy hopping – scanning surface (possibly used to recognize landmarks in migration http://www.youtube.com/watch?v=XLR8YkTEI1g&feature=related
Biology of Marine MammalsBehavior
Posture/Movement CommunicationsMutual assistance
Assist others when in trouble Enhances feeding “scout” report
Stranding/beaching – mystery; may become disoriented by storm, illness or injury; healthy individuals may follow
http://www.youtube.com/watch?v=ezzmkEQILO0&feature=fvwrel (mass stranding)
Biology of Marine MammalsMigration
Migration – usually from feeding summer areas to winter breeding area
Baleen whales tend to migrate more than toothed whalesUse landmarksEarth’s magnetic filedMay use current, temperature differences, or
day length
Biology of Marine MammalsReproduction
To keep body streamlined most male marine mammals have internal reproductive structures
Some form harems – one male and many females (“left out” males form bachelor groups)
Pinnepeds – embryo remains dormant (delayed implantation) and is not attached to uterine wall; therefore pups will not be born to early in the water (gestation is only 8 months)
Calves of cetaceans born tail first to prevent drowning
http://www.youtube.com/watch?v=GyClkrV4dI4 (beluga whale giving birth)