Marine Reptiles, Birds, & Mammals

Kingdom Animalia

Subphylum Vertebrata Land dwelling vertebrates

What did land vertebrates evolve to live on land?

What type of fertilization method do they have? Internal or external?

Descended from what animal?

A Fish Called Latimeria (Coelacanth)

http://www.arkive.org/coelacanth/latimeria-chalumnae/video-00.html?offset=0px

Having adapted to land, some reptiles, birds & mammals turned around & reinvaded ocean = marine tetrapods

Class Reptilia Endothermic or ectothermic?

What adaptations do they have to keep from drying out?

Marine Reptiles - Sea turtles, sea snakes, marine iguanas, salt water crocodiles

Do marine reptiles still depend on land?

Read “The Endangered Sea Turtles”

Class Aves Endothermic or ectothermic? Adaptations to keep from drying out?

2 types of marine birds: 1. Seabirds – spend significant part of life at sea & feed on marine organisms - Nest on land & breed in large colonies Other adaptations for living in water?

Which seabird is fully adapted for sea life?

Penguins- most fully adapted for sea life What adaptations do they have?

Bill Shapes & Feeding

Fig. 9.7

Feeding Strategies

Fig. 9.8

2 types of marine birds: 2. Shorebirds – live along the coast - Do not have webbed feet - Also common in estuaries and coastal marshes

Shorebird Bill Shapes & Feeding Strategies

Class Mammalia Endothermic or ectothermic? How are mammals different from reptiles and birds?

Order Pinnipedia - seals, sea lions, walruses Evolved from terrestrial carnivores (cats, dogs, bears) Do they still depend on land?

Adaptations for living in the water?

Sea Lions vs. Seals

Sea Lion

Seal

Sea Lions vs. Seals

Sea Lions vs. Seals

Order Carnivora – sea otters, polar bears Sea otters - smallest of marine mammals (60-80 lbs ) Adaptations for living in water?

Polar bears - semiaquatic, spend large part of life on drifting ice in the Arctic Adaptations for living in water?

Order Sirenia – sea cows (manatees, sea dugongs) Spend entire life in water Large, gentle animals (10-15 ft., 900-1300 lbs.)

Feed on sea grasses Slow reproduction (1 calf/4 yrs) Adaptations for living in water?

Only 4 species remain and all are endanger of extinction Largest sirenian = stellar’s sea cow (25 ft., 10 tons) - Extinct since 1768

Only 4 species remain and all are endanger of extinction Propellors & habitat destruction are major threats

Read the online article “Sleek? Well, No. Complex? Yes, Indeed”

Order Cetacea –whales, dolphins & porpoises Largest group of marine mammals Do they still depend on land? Adaptations for living in water?

No rear limbs on adults

Tail ends in pair of finlike horizontal flukes

Nostrils are on top = blowhole

2 Groups of Cetaceans 1. Toothless (baleen whales) How do they feed? Blow hole openings?

Fig. 9.17

Blue Whale One of largest animals that ever lived on earth Record size = 110 ft., record weight = 200 tons

2 Groups of Cetaceans 2. Toothed (toothed whales) How do they feed? Blow hole openings?

2 Groups of Cetaceans

Fig. 9.18

Read “The Whales That Walked To Sea”

Biology of Marine Mammals Diving Marine Mammals Sea Otters : 4-5 minutes; 180 feet Pinnipeds: 30 minutes; 490 – 820 feet Weddell Seal: 1hour 13 minutes; 1,900 feet Sperm Whale; 1 hour; 7,380 feet

Sperm Whale – largest of the toothed whales

Huge mass of spermaceti (wax) surrounds large nasal passages. What are these used for? When diving, nasal passages fill with water. By controlling amount & the temperature of water at different depths, it can alter density of wax & adjust its buoyancy. Enables whale to make deep dives & remain down while searching for prey.

Echolocation: sensory system based on hearing (nature’s version of sonar) Emit sound waves (clicks) & listen for echoes that are reflected back from surrounding objects. Time it takes for echoes to return tells animal how far away object is, what size it is etc. What type of whales would want to use this?

Behavior: very complex

Highly social and live in groups. Do they talk to each other? Do they play with and help each other?

Migrations: Why migrate? During summer, baleen whales migrate to productive polar regions to feed on krill. During winter, migrate to warmer waters to breed.