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Marine Reptiles and Birds. Chapter 9. Reptiles Vs. Birds Have scaly skin scaly skin limited to feet & legs Vertebrate Vertebrate Many lay eggs all lay eggs Exothermic Endothermic Found mainly in tropical and found from polar seas to
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Marine Reptiles and Birds Chapter 9
Reptiles Vs. Birds Have scaly skin scaly skin limited to feet & legs Vertebrate Vertebrate Many lay eggs all lay eggs Exothermic Endothermic Found mainly in tropical and found from polar seas to subtropical habitats tropical shores
Marine Reptiles • Belong to class Reptilia • Four main groups: sea turtles sea snakes marine lizards saltwater crocodiles
Adaptations: • Activities are dictated by the amount of warmth it receives from the sun. • Posses lungs for breathing at all stages of their lives • Have an amniotic egg; contains a large yolk to nourish the developing embryo • Egg is leathery to prevent it from losing water and drying out • Have scales
Internal fertilization • Most reptiles return to land to lay their eggs • All reptiles have a three-chambered heart except for the crocodilians; they have a four-chambered heart (enables the separation of oxygenated and deoxygenated blood) • Some sea snakes live-bear their young in the ocean
Sea turtles and marine lizards have salt glands: positioned above their eyes they secrete great quantities of salty tears; this enables them to live without access to freshwater
Have the ability to excrete very concentrated urine by reabsorbing most of the water from it.
Belong to the order Crocodilia • Often hunt by remaining just below the water’s surface, with only their eyes and nostrils above water. • Found in Africa, Asia, Australia, and the Americas • American saltwater crocodile (endangered) lives only in the Florida Keys
There are about 50 species of marine snakes • All of them are venomous • Range from 1 to 2 meters in length • Most prey on small fish • Inhabit Atlantic, Pacific, and Indian Oceans Venomous: Venom yield is low, but still considered potentially dangerous to humans. Size: 10 - 45 inches in length (25 - 114 cm.) Most snakes seen in the eastern Pacific are 18 - 25 inches long (46 - 64 cm.) Yellow-bellied sea snake
massive, highly poisonous sea snake, Aipysurus laevis, that mainly inhabits coral reefs. It is abundant in coastal waters off the northern half of Australia and southern New Guinea and in the Coral Sea. Adults may exceed 6 feet (1.8 meters) in length. Napoleon Wrasse Olive sea snake can grow up to 1.5 m and weigh up to 2 kg.They are highly venomous as they can produce 10-15 mg of venom (fatal dose only requires 1.5 mg). Fortunately, they have an inoffensive nature. They seldom bite even in self-defense. Yellow-lipped sea krait
Belong to the order Squamata; along with lizards • Have a flatter body and paddle-like tail for swimming more efficiently • Presence of salt glands in the mouth allow it to get rid of excess salts thereby maintaining normal water balance in the body • Special flap of tissue covers the nostrils which prevents water from entering the lungs • Can inflate their lungs to three-quarters of its body length; allows it to stay underwater for as long as 2 hours on a single breath
Mostly a land-dwelling animal • marine iguana swims and feeds in the ocean; live on the Galapagos Islands • Has a menacing look but quite harmless • Underwater movements are graceful • Has a flattened tail to aid in swimming • Dive into the ocean to graze on algae and seaweed that grow on rocks in the intertidal zone
The most widely distributed of all marine reptiles • Inhabit tropical and warm temperate oceans around the world • Belong to order Chelonia • Six species of marine turtles and all are endangered: Hawksbill Leatherback Loggerhead Kemp’s ridley Pacific (olive) ridley Green sea turtle
Different sea turtle species can be distinguished from one another by their size and by the pattern of scales on their top shell, carapace. • All marine turtles have a hard carapace except for the leatherback; its shell is leathery in texture • Largest marine turtle is the leatherback: average size measures 2 meters and can weigh up to 450 kg • Smallest is the Kemp’s ridley: about 60cm in length and weighs about 35kg.
Can live as long as 200 years • A sea turtle’s body is smooth and streamlined for ease of movement in the water • Limbs have evolved into flippers and can swim at speeds of up to 32km/hr • Have fatty deposits and lightweight bones for added buoyancy • Can stay underwater for up to 40 minutes on a single breath
Feeding Sea Turtles • Prefer coastal waters where food is plentiful • Have no teeth but strong jaws; used for breaking open shells if crabs, clams, and other shelled fish or for eating underwater vegetation Loggerhead: mollusks, crustaceans, fish, and jellyfish Hawksbill: mollusks and crustaceans, jellyfish and algae Green sea turtle: graze on turtle grass and eel grass that grow in shallow waters
Pacific ridley: invertebrates that live in eel grass • Leatherback: jellyfish Sea turtles that eat jellyfish sometimes die when they accidentally ingest garbage such as plastic bags, which resemble their prey
Reproduction and Development • Mature sea turtles return every few years to the beaches on which they were born to mate and lay their eggs • Mating occurs in shallow offshore waters • Female turtles swim to the shore and, during the night, emerges onto the beach. • Sea turtle drags herself up the slope of the sandy beach to find a nesting site above the high tide mark
Female first uses all four limbs to dig a depression in the sand; then uses her hind limbs to scoop out a hole about 30-60cm deep. • She lays about 100 fertilized leathery eggs • Over time, she will come ashore four or five more times to lay eggs • Turtle eggs that develop at about 28 degrees C and below become males; those that develop at 30 degrees C and above become females. • After development is complete, the hatchlings break through their shells and dig their way to the surface.
Seabirds: birds that depend on the ocean for their survival • Nearly 9000 species of birds • Belong to class Aves • All birds have feathers, which are attached to the skin. 2 main types of feathers: down feathers contour feathers powder feathers
Down feathers are the small, fluffy feathers closest to the skin • Trap warm air and hold in body heat
Contour feathers are the largest feathers that cover the wings and the body
Preening: a form of grooming where birds use their beaks to spread waterproof oil through their feathers • Powder feathers repel water to protect the underlying down feathers Some birds have a special gland near their tail that produces a waterproof oil
Most birds have lightweight hollow bones, an adaptation for flight • Some diving birds have denser bones; adaptive for birds that spend time swimming underwater in pursuit of fish • All marine birds have to return to land, or ice, to breed • Eggs are encased in a hard calcium-rich shell
Often both parents tend the eggs by keeping them warm and protecting them from predators • Birds nest in a variety of habitats: tree branches cliff edges along a rocky coast patches of vegetation pebbles and sand on a beach few stones out on the ice • Offspring are fed by the parent birds
Have a variety of feeding methods: foraging through sand and mud along the shoreline short trips to the sea, diving several times a day for their catch of fish and invertebrates
Seabird species that spend much of their time in and on the water have webbed feet for paddling and swimming • Have salt glands located on the nostrils • Conserve water by excreting a concentrated uric acid
Beak Common Shorebirds • You can tell what birds eats what by looking at its • Sandpiper: • Narrow pointed bill for poking in the sand for small invertebrates, worms and insects • Common shorebirds that move in small flocks in the intertidal zone
Oystercatcher: • Uses its long, red knifelike beak to catch and eat various types of mollusks • Inhabits the marshes and sandy beaches along parts of the Atlantic and Gulf coasts
Snowy Egret: • Inhabits salt marshes along Atlantic and Pacific coasts • Long flexible neck and pointed bill used for quickly grabbing small fish that dart in the shallow waters • Long stiltlike legs gives it the advantage of being able to spot fish
Sea Ducks: • Use their webbed feet like paddles for moving through the water • Layers of fat in addition to down and waterproof feathers keep the birds warm and dry • Marshes are used for nestion • Various species dive into the ocean to feed on mollusks, crustaceans, and fish
Cormorant: • Dives from the sky for its food • When it spots a fish, it folds its wings, tucks its feet, and dives into the water, where it catches the fish with its hooked beak
Common Tern: Nests on sandy beaches Makes spectacular aerial movements Can hover over the water before it dives to catch a small fish
Brown Pelican: • Large birds that live along the Florida, Gulf , and California coasts • Literally “make a splash” when they dive from the sky into the water. • Uses its large throat pouch like a net to scoop up fish • Water is squeezed out of the pouch and the fish are then swallowed headfirst to prevent the dorsal spines from getting stuck in the bird’s throat
Black Skimmer: • Flies low over the water, with the tip of its lower jaw just beneath the surface • By skimming the water, it eventually makes contact with a fish which it then swallows while still in flight
Osprey (fish hawk): • Swoops down from its nest on top of a tree to grab fish right out of the water • Keen vision • Has talons • Lives along the Atlantic, Pacific, and Gulf coasts
Wandering Albatross: • Found in the South pacific • Among the largest of all the seabirds with a wingspan of about 3 meters • Adept at gliding effortlessly on air currents over the ocean • Bird rarely stops flying or gliding, except for breeding, and may actually circle the entire globe
Penguins: • Most aquatic of all seabirds • 15 species, all but one live in the southern hemisphere • Have no flight feathers; completely flightless • Excellent swimmers and divers; can travel at speeds up to 24km/hr • Have dense bones • Eat fish, krill, squid, and shellfish • When they breed, males and females share the duties of warming the egg and feeding the chicks Galapagos penguins
Can survive the cold air and waters of the Antarctic because they have a thick layer of fat and densely packed soft down feathers for insulation All birds are endothermic (warm-blooded) Chinstrap penguin