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)