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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