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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 endo thermic . Traits.
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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 Fur coat No external ear flaps FLIPPERS Seal molting clip
SEA LIONS AND FUR SEALS • Have visible ears • Hind flippers that can be rotated forward for use as limbs on land • Walkor 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
PINNIPEDDIET • 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 slowheartbeat to use less oxygen • Have a thick layer of blubber to protect them from the cold • Have bigger lungs • Can slowmetabolism
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
TRAITS OF CETACEANS (WHALES) • Mammary glands • Endothermic • Viviparous • Smooth skin • Blubber under skin
KINDS OF WHALES • Odontecti - toothed whales • Mysteceti - baleen 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
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 and Porpoise Differences • Dolphin • Porpoise
The family Dephinidae includes Pilot whales Belugas Killer Whales Bottlenose Dolphins
FLUKESFLUKES • 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
Dolphin’s Head • Well defined rostrum (snout) • Conical interlocking teeth designed for grasping • 71-104 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
DOLPHINSENSES • 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 3 - 7 mph • Burst of up to 40 mph • Regularly dive 10 - 150 feet • Deepest trained dive up to 1,800 feet • Average of 1 - 6 breaths per minute • Dives can last 8 - 10 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
DOLPHIN RESPIRATION • A dolphin exchanges 80 - 90 % 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 98.4 0F • Body Fat is about 18 - 20 %
DOLPHIN SOCIAL ORGANIZATION • Live in groups called pods(2 - 20 in pods) • Pods are based on age, sex, and familial relations • Mature females and offspring • Mature males and sub adult males • Hunt together in teams • Have dating rituals and friendships • Express emotion
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 42 - 48 inches and weigh 25 - 40 lb. • Calves may nurse for 12 - 18 months 2 - 3 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 DOLPHINSpage 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 • Blowhole • Frontal Air Sac • 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