Marine Reptiles, Birds, and Mammals

Chapter 9

Marine Reptiles

• Skin covered with scales-prevents water loss

• Eggs have leather shell to prevent water loss as well

• Ectotherm-body temperature fluctuates with environment

Sea Turtles

• Only 8 species of sea turtles

• Armor-like shell called a carapace

• Carapace fused to backbone

• Cannot retract head into shell

• Legs are modified flippers

• Leave water only to lay eggs-return to same location every 2-4 years

• 100-160 eggs laid at a time• Eggs hatch after about 60 days

incubation• Eggs/young are easy prey

Sea Snakes

• Approximately 55 species of sea snakes

• Ovoviviparous

• Carnivorous- fish/fish eggs

• Closely related to cobras

• Venomous bite

• Rarely aggressive

• Small mouth

• Hunted for skin

Other Marine Reptiles

• Marine Iguana-basks on rocks to warm up after a cold swim. Eats seaweed and can dive up to 33 ft.

• Saltwater crocodile-lives along the coast or in mangrove swamps in the Indian Ocean, Australia, and some Pacific Islands. Among the most aggressive of marine animals- more feared than sharks.

Seabirds

• Endotherms- constant body temperature

• Waterproof feathers (oil glands) to conserve body heat

• Nest on land but feed mostly at sea• Webbed feet • Some can fly

Penguins

• Flightless-wings are modified flippers• Spectacular swimmers• Clumsy on land• Adapted to cold temperatures- layer

of fat under skin; waterproof feathers• All but one of 18 species live in

Antarctica

• Galapagos penguin- equator

• Larger penguins feed on fish/squid

• Smaller feed mostly on krill

• Male protects the egg for 64 days

• Female feeds chick by regurgitating her food until about 5 1/2 months

Tubenoses

• Tube-like nostrils

• Beak curved at tip

• Skillful fliers

• Catch fish at surface or scavenge on dead birds/whales

• Male/female faithful to each other

• Incubation of young- 8 months

Pelicans

• Catch fish in pouch below beak

• Cormorants- black, long necks, dive to pursue prey

• Frigate birds- narrow wings, forked tails, catch prey from surface or force other birds to regurgitate fish in mid-air

Gulls

• Predators/scavengers

• Eat fish, eggs, young, from garbage dumps, anything leftover from humans

• Tern is a type of gull that hovers over prey before swallowing it whole.

Marine Mammals

• Endotherms

• Hair retains body heat

• Viviparous

• Has a placenta and mammary glands

Seals, Sea Lion, & Walruses• Pinnipeds• Have paddle shaped flippers for

swimming• Rest/Breed on land• Predators (fish/squid)• Layer of blubber under skin acts as

insulation, provides buoyancy, and is a food reserve

• Males called bulls; females called cows

• Main difference between a seal and sea lion- seal cannot move rear flippers forward

• Walrus has large tusks and feeds on invertebrates, mainly clams

Sea Otters

• Smallest marine mammal

• Lack a layer of blubber

• Dark brown fur attracts hunters

• Became almost extinct until protected in 1911

• Playful and intelligent

• Spend most of time in water other than breeding and giving birth

• Live around kelp

• Eat clams, mussels, crabs, sea urchins, and fish

Manatees (Sea Cows)• Front flippers only• Gentle, peaceful• Live in groups• Strict vegetarians• Hunted for skin, meat, and oil• Reproduce slowly- 1 calf every 3

years• All 4 species in danger of extinction

Whales, Dolphins, and Porpoises are in a group called the Cetaceans

• Spend entire life in water

• Breathe air- can drown

• “warm blooded”

• Produce milk for young

• Front flippers only

• Have a dorsal fin

• Blubber provides insulation

• Nostrils form a blowhole

• About 90 species, other than 5 species of freshwater species

Two categories of cetaceans:

1. toothless, filter-feeding whales

2. toothed, carnivorous whales

Toothless, filter-feeding

• better known as baleen whales

• baleen is a flexible, fibrous plate that hangs from upper jaw

• made of same material as hair and nails

• feed by taking a mouthful of water and squeezing it through bristles- filter feed

• largest animals on earth

• two blowhole’s

• blue whale is the largest whale of all- males average 80 ft and females 110 ft

• other types of baleen whales- fin, humpback, right, bowhead, gray

Toothed, carnivorous

• teeth adapted for fish, squid, and other prey

• teeth only used to catch prey- food is swallowed whole

• one blowhole• largest of this group is the sperm

whale

• material from squid beaks found in stomach called ambergris- used in perfume

• killer whale is black/white and has a taste for seals, penguins, sea otters, and even other whales

• no confirmed cases of attacks on humans

• Although small- dolphins and porpoises are whales

Dolphins/Porpoises:

• Playful

• Social

• Easily trained• Travel in “pods”

Whaling- whale hunting:

• In the 1600’s Europeans exploited whales

• Harpooned from small open boats- In 1800’s harpoons were attached to explosives

• Blubber provided oil for soap and lamps

• Killed for meat

• Whales have a very low reproductive rate (about 2-3 years) so this devastated the population

• Some nations even developed ships that could process carcasses at sea.

• Blue whales were a prime target. One whale yielded 9000 gallons of oil.

• 80% of the whales caught were sexually immature. This added to decreasing number.

• 1946-20 nations developed the IWC (International Whaling Commission) to regulate over fishing

• IWC set annual quotas for the # of whales to be killed

• Demand for whale products decreased due to replacements, so in 1972 the Marine Mammal Protection Act of 1972 banned all hunting of marine mammals.

• The affects of whaling are still being felt.