marine vertebrates reptiles and birds. 7 classes agnatha condrichthyes osteichthyes reptilia...

Marine Vertebrates

Reptiles and Birds

7 classes

• Agnatha

• Condrichthyes

• Osteichthyes

• Reptilia

• Amphibia (no marine species)

• Aves

• Mammalia

Class Reptilia

• (3 major groups of marine reptiles)• Only marine reptiles on our coast are

American Crocodile and 5 species of sea turtle

• Sea snakes are also marine reptiles, but none are in the Atlantic

• Cold blooded, air breathing, covered with scales

• Internal fertilization

3 groups of marine reptiles:

• Sea turtles

• Sea snakes

• Marine lizards

• mostly tropical. Why?– cold blooded

Turtles

• Lightweight, streamlined shell

• ribs, backbone are attached to shell

• Top – carapace• Bottom – plastron• Neck cant be pulled into

shell• Legs are modified paddle

like flippers• Pharynx acts like gill

Turtles

• Specialties– salt glands – eyes (tears are salty)– Osmoregulation

• excrete nitrogen wastes as uric acid crystals• reabsorb water from urine• Green sea turtle unique – produces large amounts

of watery urine

Turtles

– Turtle migration – every 2-4 years, they go back to ancestral nesting areas.

• Instinct guides them• Eggs – shell in sand and moist

– protects from predators– keeps warm– keeps from drying out

• Female lays eggs 5 times each year• After 60 days, babies hatch

Turtles

• Cold – stay in warmer water– Exception – leatherback turtle (increased fat and

blood flow system to decrease warm blood to skin)• Fat deposits or flippers• Spongy bone to float• Green sea turtle has green fat• Streamlined, flippers, flat from top to bottom to

decrease water resistance• Leatherback can eat Portuguese Man of War

without getting stung• Exploited for meat, jewelry, oil and eggs

• Lizards

• only living marine lizard is the Galapagos marine iguana

Birds

• Bouyancy

• fatty deposits

• thin, light bones

• oil glands (secrete preen)

• air sacs within thorax

Birds

• Most birds (except cormorant and frigate birds) float on the water

• Warm blooded

• Evolved from reptiles

• Most can fly

• All have feathers

Birds

• lightweight, durable insulation• Minimal taste and smell• Hearing and sight are acute• Excess salt accumulates near nostrils and oozes

out• High metabolism, 4 chambered heart• webbed feet typical• All marine birds must return to the shore to nest

Gulls:

• lack of specialization• feed on anything• scavengers• can fly up with a clam

and drop it to a hard surface cracking it open

Cormorants

• eat fish• swim• heavy bones• no oil glands• plumage is not

waterproof • need to dry feathers

– wings outstretched on rock to dry

• Produce lots of guano (solid waste)

Penguins

• thick layer of fat under the skin

• dense fur like feathers

• short appendages to maintain internal body heat

• Emperor can dive to 900 feet for up to 18 minutes!

Pelagic Birds

• spend almost their entire lives beyond sight of land– Puffins– Albatrosses