Marine Mammals Comparative Analysis By Dr. M. & Mr. K.

1.) Most are viviparous. 2.) Have mammary glands which produce milk to feed young. 3.) Young are usually altricial and need to be cared for by parents for a while. 4.) Are endothermic. Traits

5.) Most are carnivorous (not marine manatee). 6.) Have well developed organ systems, especially the nervous system. 7.) Many are covered with fur, but some are not. 8.) Top feeders in Marine food chain. Traits

PINNIPEDS Are fin footed mammals Are covered with fur Are excellent swimmers Are descendants of felines

Family’s of Pinnipeds True seals Sea Lions and Fur Seals Walruses

TRUE SEALS Have no external ears Hind flippers are permanently oriented backwards Wiggle on their bellies on land and swim via undulations of the body

TRUE SEAL FLIPPERS No external ear flaps Fur coat Seal molting clip

SEA LIONS AND FUR SEALS Have visible ears Hind flippers that can be rotated forward for use as limbs on land Walk or gallop on land and swim via powerful strokes of their front flippers

WALRUSES Have no external ears Hind legs rotate forward Only 1 species which lives in the artic ocean Eat shellfish and krill Have tusks Have air sacs in neck that can be inflated

PINNIPEDS ON PARADE

PINNIPED DIET Most Pinnipeds eat: Fish Squid Octopus Other invertebrates

PINNIPEDS ARE PREYED UPON BY Killer whales White sharks Other large sharks Lice Internal parasites

DIVING ADAPTATIONS IN PINNIPEDS Store oxygen in muscles Have more blood than land animals in proportion to their body size Can direct blood flow to only vital organs Can slow heartbeat to use less oxygen Have a thick layer of blubber to protect them from the cold Have bigger lungs Can slow metabolism

PINNIPED MATING Practice Harem Mating -a male defends a stretch of territory and mates with many females Females give birth within the males territory Some males are excluded and live in bachelor groups

PINNIPED MATING Giant Belligerent males mate with small females Males engage in pushing, biting, and bluffing contest Old males who lose disappear and are never seen again

PINNIPED LIFE CYCLES Females give birth to 1 pup then leaves the pup on land to feed at sea She returns once a week for a day long nursing session Pups enter the water 4 weeks after birth Males leave the island 1st, then females and pups leave in November for coasts south

HOW PINNIPEDS BENEFIT HUMANS Provide food Retrieve missiles for navy Retrieve traps and tools Entertainment

WHAT IS A WHALE?

TRAITS OF CETACEANS (WHALES) Mammary glands Endothermic Viviparous Smooth skin Blubber under skin

KINDS OF WHALES Odontecti - toothed whales Mysteceti - baleen whales

EVOLUTION OF WHALES

Characteristics of Odonteceti Conical shaped teeth Smaller than mysteceti Are carnivorous (eat fish, squid, etc.) Can dive up to 2000 m Can breath hold up to 90 minutes Over 65 species Sperm whale is largest toothed whale (65 feet)

Odonteceti continued Communicate while hunting Live and travel in groups called pods Some mate for life Females and offspring travel in groups with last year’s offspring Some older males live in bachelor groups Oldest males like Moby Dick live solitary lives May migrate - wintering near equator and summering near poles

Traits of Odonteceti

Teeth of odonteceti

WHALES HUNTING

DOLPHIN AND PORPOISE DIFFERENCES Dolphins Have beaks Conical teeth 4m in length Extroverted Sociable Live in groups Porpoises No beaks Spade shaped teeth Reach 2m Introverted or in pairs

Dolphin and Porpoise Differences Dolphin Porpoise

The family Dephinidae includes Pilot whales Belugas Killer Whales Bottlenose Dolphins

FLUKES Each lobe of the tail is a fluke Flukes have no bones or muscles Muscles of back and caudal peduncle move flukes Spread of flukes=20% of body length Arteries and veins are oriented in a countercurrent system

COUNTERCURRENT SYSTEM

Dolphin’s Head Well defined rostrum (snout) Conical interlocking teeth designed for grasping teeth Eyes are on the side of the head near the corners of the mouth Ears are located behind the eyes. Small openings with no external flap

DOLPHIN SENSES EXCELLENT VISION IN AND OUT OF WATER Eyes have rods (black and white) and cones (color vision) Skin is sensitive to touch Have taste buds No olfactory bulb, possibly no sense of smell

DOLPHIN SWIMMING Regularly swim at mph Burst of up to 40 mph Regularly dive feet Deepest trained dive up to 1,800 feet Average of breaths per minute Dives can last minutes

ADAPTATIONS FOR DIVING Heartbeat is reduced Blood is directed to vital organs (heart, lungs, and brain) Muscles have myoglobin, which stores oxygen and helps prevent oxygen deficiency

Adaptations for diving

DOLPHIN RESPIRATION A dolphin exchanges % of the air in its lungs with each breath (humans exchange 17%) Dolphins inhale and exhale in less than 2 seconds Water vapor is expelled through the blow hole

DOLPHIN SLEEP Russian studies show that dolphins may have deep sleep in one hemisphere at a time.

DOLPHIN BODY REGULATION Body Temperature is F Body Fat is about %

DOLPHIN SOCIAL ORGANIZATION

Social Behavior

FOOD Eat fish, squid, and crustaceans Eat 4 - 6% of body weight daily Do not chew their food but swallow it whole head first so spines won’t catch in their throat

REPRODUCTION Gestation is 12 months Worldwide calves are born all year Usually give birth to 1 calf every 2 years Calves are inches and weigh lb. Calves may nurse for months hrs a day 1 minute at a time Dolphin milk is 17% fat, 10% protein, 71% water. (human is 4.5% fat, 1.1% protein and 87.4% water)

ECHOLOCATION IN DOLPHINS Air sacs - make clicks Melon - focuses clicks Lower jaw - detects returning sounds

ECHOLOCATION IN DOLPHINS page 2 Used to sense landscape in the dark Used to locate prey May be used to locate one another May be used to stun prey Works like sonar Echolocation video

Echolocation in a Sperm Whale A.Blowhole B.Frontal Air Sac C.Distal Air Sac D. Monkey’s Muzzle

ECHOLOCATION Gives the whale a detailed picture of the seascape Allows whales to dive to depths of 2,000 meters to locate prey and avoid injury in total darkness

ECHOLOCATION IN SPERM WHALES Clicks are generated by a pair of hard lips tightly compressed inside the skull called the monkey’s muzzle Sound is focused by an oil filled organ inside the head called the spermeceti organ (occupies 40% of whale length) once used in oil lamps and helps adjust density in the sperm whale Returning sounds are received by the lower jawbone and processed by the nervous system.

ECHOLOCATION IN SPERM WHALES

Dolphin Intelligence Have a brain structure similar to humans Can process the complexities of social relationships when living in organized groups Have a large number of interconnections between neurons

INDICATIONS OF DOLPHIN INTELLIGENCE Can learn languages and respond correctly to sentences never uttered to them before ex. Frisbee fetch hoop Can rearrange environment to follow a command ex. Swim through a hoop, but hoop is on the bottom of the pool

TRAITS OF MYSTECETI (BALLEEN WHALES) Have baleen instead of teeth Are larger than toothed whales ex. Blue whale is 100 feet long and weighs 300,000 lbs. - Largest animal on earth Have 2 blowholes Ribs are are not attached to sternum Invent own stunts Play competitive sports

HUMPBACK WHALES Eat enough in summer to last rest of the year Hunt together creating bubble nets to drive schools of fish close together and then swim up from underneath Communicate over long distances Males sing long songs over and over again to attract females Breach, lobtail, and spyhop

HUMPBACK WHALES

BLUE WHALE

BALEEN

Baleen Whales Documentary