The basics

Marine Tetrapods 4 limbs Breathe air with lungs Terrestrial ancestor species Reptiles, birds, mammals + 1 species of frog in Asia

Part 1 of test You will be identifying BY ENGLISH, COMMON NAME, not latin species name.

Beluga Whale

Blue Whale

Dolphin

Humpback whale

Manatee

Orca (Killer Whale)

Sea Otter

Sea Lion

Seal

Walrus

FYI Fossil and DNA evidence shows that the ancestors of ocean mammals were LAND mammals.

Traits of ALL Marine Mammals Viviparous (internal nourishment and development of fetus) Body hair (on many but not all) Mammary glands Specialized teeth (type of teeth corresponds to type of food) External opening of reproductive system DIFFERENT from external opening of digestive system

Pinnipeds Fin footed mammals Carnivores Walrus, seal species, sea lion species Only one species of walrus Seals swim w/ rear flipper for power Sea lions swim w/ front flippers for power

Manatees + Dugongs Paddle like tails No pelvic limbs Herbivores Shallow tropical oceans

Cetaceans (whales) No pelvic limbs (do have remnants of pelvic bones in skeleton!) No body hair Dorsal blowholes for breathing Swim w/ horizontal tails for power Baleen- adaptation for filter feeding in some whales Toothed whales- carnivores

Breathing Hypoxia- state of small amounts of oxygen in the body Must reach surface of water to breathe. Amount of time spent underwater between breaths varies based on species Rapid exhale-inhale pattern at surface then hold breath while underwater called APNEUSTIC BREATHING PATTERN Lungs collapse from water pressure in deep dives- marine mammals can handle this!

Don’t memorize, but be impressed! ANIMALMAX KNOWN DIVING DEPTH (m) MAX KNOWN DURATION OF TIME UNDER WATER (min) Human676 Dolphin53512 Sperm whale Manatee6006 Sea otter232.3 Elephant sealMale 1530, Female 1273Male 89, Female ~100 meters under water the lungs collapse completely

HOW??? Oxygen forced out of lungs as they collapse store oxygen in red blood cells Have more red blood cells than humans

Communication Sound! They “sing” to each other. Humpback Whale "songs“ For reproduction and hunting Behavior- watch each other’s movements and move in appropriate response. Dolphins play and hunt in groups Orca's use sound and visuals to hunt together

Reproduction Sexual reproduction Live birth Babies must be able to swim with mom immediately Milk often has very high fat content to help babies grow fast Time the mother’s spend with baby varies greatly mother and calf gray whale Baja Mexico FYI Newborn gray whale ~16ft long, compared to mother ~49ft long!

Chapter 12

This week Friday Starting Thursday, ending Friday we are watching the Blue Planet episode about the North and south Pole ecosystems

North and South Poles are VERY different!

NORTH: Arctic Mammals Polar bears, harp seals, hooded seals, ringed seals, walruses, gray whales, killer whales, beluga whales, narwhals

Adaptation: Milk Fat Milk produced can be up to 60% fat so the baby gains weight quickly. Cow’s milk 3-5% fat Needed because newborns do not have enough fat and fur to stay warm on their own. Hooded Seals: Baby weaned after 4 days! Adults need to maintain large amounts of blubber/fat in order to survive in the cold water/air.

Adaptation: Migrating animals Cold water contains more small organisms to feed on than warm water Gray Whales migrate 18,000km per year: Summer near Bering Sea (lots of food) ~September leave and start swimming south January-March near Baja, Mexico (calves born there) ~April leave and start swimming north again

Time on Land v. in water Common for sea mammals to give birth OUT of water WHY??? What common traits do you see in the seal pups below? (cute doesn’t count!) EXCEPTION: Cetaceans

Mating Areas on land EXAMPLES: Walrus leks Lek- arrangement where males pick a spot and show off, females get to decide which male with mate with FYI walrus gestation= 15 months! Baby spends about 1 year living off milk from mom. walrus on russian coast

Why are polar bears considered sea mammals? Ursus maritimus Hunt on sea ice Will swim long distances for the next meal

Polar bears Polar bear video (on DVD) e=UTF- 8&hq=&hnear=0x526fd949c8f9f537:0xd10c44d dd,Churchill,+MB,+Canada&gl=us&ei=bOomU- uMIIfF0QGCi4GgCA&ved=0CKkBELYD e=UTF- 8&hq=&hnear=0x526fd949c8f9f537:0xd10c44d dd,Churchill,+MB,+Canada&gl=us&ei=bOomU- uMIIfF0QGCi4GgCA&ved=0CKkBELYD YES, polar bears have black skin. WHY is that useful? Polar bear fur is not actually “white”, but nearly see- though. (like a dusty window)

How Baleen Whales Eat Skimming Engulfment Gray whales have short baleen therefore a different way of feeding

Toothed Whales in Arctic All carnivores Living in groups called “pods”

And the strange animal award goes to… THE NARWHAL Eat fish and squid in deep arctic waters 1 tusk on males(left incisor tooth) Can sense salinity, temperature, and pressure of water!

Adaptations for Hunting Echolocation (like sonar that submarines use) Works for schools of fish, not good for mammals or individual fish Vision and Brute force Works for individuals or small groups of hunters going after other sea mammals Orca hunting video shown last week

SOUTH: Antarctic Mammals Weddell, crabeater, leopard, elephant seals Humpback, orca, minke, fin whales

For the most part animals in the antarctic require similar adaptations as those in the arctic Need to survive cold air/water Need to eat enough Need to avoid predators

Adaptation: teeth Teeth are designed for the animals specific prey species Small or large teeth or baleen I hope the penguin moved after this picture was taken!

Surprising uses of teeth Weddell seal uses teeth to scrape open an air hole in ice. Teeth become smaller and duller over time Animal becomes less proficient at finding prey Weddell seals tend to have shorter lives than other species.

How humans changed Antarctic Ecosystems Cold water = many fish Overfishing and whaling in last 100 years Fewer larger mammals and more smaller mammals Example: ~30000 blue whales feeding in 1929, ~2000 blue whales feeding 2010 Remember the moral of Happy Feet!

The Antarctic Food chain Depends on krill Top predator is IN the water: Leopard Seal leopard seal hunting

Toothed whales All are migrating animals Here Killer Whales mainly eat seals Sperm whales are most widely distributed whales on earth Think Moby Dick.

Final Thought Question Why are the arctic and antarctic ecosystems vital to the entire world even though they have fewer types of organisms than other areas?