MARINE MAMMALS

Mammals have a 4 chambered heart.

Mammals are warm-blooded.

Mammals have hair/fur.

Mammals have mammary glands.

Mammals give birth to live young.

1. PINNIPEDS• Seals, Sea Lions, Walruses• Marine mammals that have flippers and

blubber.• Need to breed on land. • Live in cold water• Mostly carnivores and feed on squid and

fish.• Streamlined bodies and are excellent

swimmers.

A. Seals• Have rear flippers.• They move forward by

pulling themselves along the ground.

• Do not have ear flaps.• There are approximately

19 species.

B. Sea Lions• Also called eared seals,

because they have external ear flaps.

• They can move their rear flippers forward to walk.

• They are graceful and agile swimmers.

C. Walruses• Have large

protruding tusks for digging up mollusks.

• They have stiff whiskers for feeling around on the ocean floor.

• They are the largest Pinniped, weighing up to 2700 lbs!

2. SEA OTTERS

• They are the smallest Marine Mammal, weighing 60-80 lbs.

• They lack a layer of blubber, and make up for it by trapping air in their dense fur.

• They eat mostly shell fish and urchins and spend most of the day maintaining their fur.

3. POLAR BEARS• They are semi

aquatic, so they inhabit both the land and the sea.

• They feed primarily on seals.

• They have recently been put on the endangered species list because of loss of habitat due to global warming.

POLAR BEAR VS.WALRUS COLONY

• http://www.youtube.com/watch?v=v6iDtvGbIOU

4. CETACEANS• This is the largest group of Marine

Mammals, consisting of Whales , Dolphins, and Porpoises.

• Spend their entire lives in the water. • They are streamlined, and look fish-like.• They breathe air through lungs and have

nostrils on the tops of their heads called a blowhole (some single, some double).

• There are more than 90 species divided into two groups: – Toothed Whales– Toothless Whales

A. Mysticeti = Baleen Whales• Instead of teeth, have rows

of flexible, fibrous plates, that hang from the upper jaws (called a Baleen).

• These are used to filter out plankton and tiny organisms from the water.

• The largest animals to ever have lived on this planet.

• 13 species

• Blue Whale is the largest at up to 110 ft. long, and up to 200 tons.

Examples

• Right Whale• Minke Whale• Grey Whale• Sei Whale • Bowhead Whale• Fin Whale• Blue Whale• Humpback Whale

Sei Whale & Calf

Minke Whale

Baleen Whale General Anatomy

B. Odontoceti = Toothed Whales• Teeth are adapted for a

diet of squid, fish, and other prey and are used to catch and hold prey, not to chew it.

• There are 80 species.

• The largest is the sperm whale, made famous by the novel “Moby Dick”.

Examples

• Sperm Whale• Beaked Whale• Killer Whale• Pilot Whale• Beluga Whale• Bottlenose Whale• Dolphins• Porpoise

Pilot Whale

Northern Bottlenose Whale

Dolphins

• Highly intelligent creatures, that can be easily trained, are playful, and have been known to “escort” ships.

• It is common for dolphins to get caught in fishing nets meant for other species.

DOLPHIN ANATOMY

Porpoises

• Porpoises are divided in to six species.• Shorter than the average dolphin, more shy,

and they don’t tend to live as long.• Have flattened, spade-shaped teeth.

Dall's Porpoise

Harbour Porpoise

Communication• One way Cetaceans communicate is

through Echolocation (nature’s version of sonar).

• They release tiny bubbles through their blowholes and make clicking sounds to communicate with each other, determine distances, and warn others about danger.

• The Melon (fatty structure on the top of their heads) focuses and directs these sound waves.

Secrets of Dolphin Sonar • http://www.youtube.com/watch?v=ZoNDW0zSRNo&feature=fvsr

Humpback Whale Song• http://www.youtube.com/watch?v=-hGSBnkm8Qs&feature=fvsr

Breaching• When whales leap in the air and

loudly crash on the surface of the water.

• This can be a warning signal, a way to get rid of external parasites, a fun activity, or a way of scanning the surface.