Marine Biology 1060 Study Guide Chapter 8
Terms to know:
Tetrapods Class Amphibia
Class Reptilia Class Aves
Class Mammalia Ectotherm
Endotherm Ovoviviparous
Sea snake
Penguin
Tubenoses
Pelican
Cormorant Frigate Bird
Gull
Tern
Viviparous
Placenta
Mammary gland
Pinnipedia
Seal
Sea Lion
Blubber
Fur seals
Walrus
Carnivora
Sea Otter Manatee
Dugong
Cetacea
Whale
Dolphin
Porpoise
Baleen
Flukes
Mellon organ Spermaceti
Toothed whale Baleen Whale
Ambergris
Echolocation
Migration Order Chelonia
Order Squamata Order Crocodilia
Order Spenisciformes
Order Porcellariiformes
Order Chadriiformes Order Ciconiiformes
Order Pelicaiformes
Order Pinnipedia Order Carnivora
Order Sirenia Order Cetacea
Suborder Mysticeti
Suborder Odontoceti
Concepts:
I. Marine Amphibians - there are none
II Marine reptiles - Class Reptilia
A. general
1. There are three Orders
a. Squamata - Sea snakes, Galapagos Marine Iguana
b. Chelonia - Sea Turtles
c. Crocodilia - Salt water crocodile
2. All are ectotherms (cold
blooded)
3. Sea snakes are ovoviviparous,
rest are land egg layers and must return to shore to lay eggs
4. all are Tetrapods with
lungs
5. there are not many modern
marine reptiles though there were many now extinct forms historically
B. Order Squamata - Sea Snakes, Marine Iguana
1. Sea Snakes
a. most are ovoviviparous and give live birth at sea
b. most closely related to the cobras
1. highly venomous
2. small mouth, fangs at rear of their jaw makes human bites difficult
c. truly marine - entire life at sea
1. flattened tail acts as a fin
d. mostly feed on fish
e, 55 species , all are tropical Indo-pacific
2. Marine Iguana
a. found on the Galapagos Islands
b. large lizard
c. dives to 10 meters to feed on seaweed
C. Order Crocodilia - Salt Water Crocodile
1. only one species
2. distributed through the
East Indian Ocean, Australia and some western Pacific Islands
3. record is 33 feet, average
is 20 feet today.
4. aggressive - actively
takes human prey
D. Order Chelonia - Sea Turtles
1. Only 8 species worldwide
2. All are threatened or
endangered
a. fishing practices
1. T.E.D.s are turtle excluder devices used in American water nets to release
accidental catches
b. many are hunted for meat, eggs and shell
1. example: Kemp's Ridley Sea Turtle (most endangered sea turtle)
is a colonial nester that only
nests on specific beaches in Mexican waters hunted to near extinction for
eggs
2. example: Hawksbill Turtle heavily hunted for "tortoise shell" for glasses
and jewelry
c. coastal development:
1. since all must come ashore to lay eggs, loss of beach and shore habitat
to tourist and housing
development reduced reproduction
2. light pollution of nesting beaches confuse hatchlings which use reflected
starlight to find the ocean
3. Important examples:
a. Kemp's Ridley - most endangered - colonial nester
b. Green Sea Turtle - heavily exploited for meat and eggs
c. Leatherback Sea Turtle - largest to 800 labs
III. Seabirds - Class Aves
A. General
1. All are endotherms -
warm blooded
2. All lay amniote eggs
and so must nest on land
3. Adapted for flight
a. hollow bone
b. wings
c. feathers
d. high metabolism
e. even flightless forms such as penguins have flying ancestors and so
show many of these characteristics
4. Class Aves - Taxonomy
for this section
a. Order Sphenisciiformes - Penguins
1. All found in the Southern Hemisphere
2. Most in cold Antarctic waters - only exception is the Galapagos Penguin
3. truly flightless - wings adapted as flippers for swimming
4. small, dense, waterproof feathers adapted to act as insulation
5. have a blubber like fat layer over their skin for insulation
6. feed variously on small fish and krill
7. Reproduction varies but all form breeding colonies
a. example: Emperor Penguin
1. Male huddle in large groups and incubate a single egg by holding it
on his feet under a naked
"brood patch" on the belly through the Antarctic winter
2. Female leaves and feeds at sea during incubation
3. Egg Hatches with the coming of summer which is the time of greatest
abundance of krill
4. both parents take turns feeding at sea and returning to regurgitate
food for the chick for 5.5 months
5. Older chicks are herded into groups called creches and Baby-sat while
parents are away
6. nesting pairs are mated for life
b. Order Porcellariiformes - Tubenoses: Petrels, Albatrosses
1. have distinct "tube" shaped nostrils on the top of the beak
2. have a salt gland for excretion of excess salt
3. many catch fish while in flight
4. most nest on remote islands and mate for life
5. some species make extremely long migrations
a. several nest in Antarctica and migrate oversea to summer and feed in
the Arctic
b. the Wandering Albatross juveniles spend two or more years traveling
around the
Southern Hemisphere before returning to land to nest
c. Order Pelicaniiformes - Pelicans, Cormorants and Frigate birds
1. Pelicans
a. diving birds with large pouches under their beak
1. head and neck are specialized to absorb shock when they plunge into
the water at high speed
b. pouch acts as a container for sieving water after the bird dives, not
as a storage place for food
c. Two are found in the U.S.
1. Brown Pelican is our common species on the East Coast
2. the Brown Pelican was almost extinct as a result of pesticide pollution,
now making a comeback
2. Cormorants
a. long necked fish eating diving birds
b. used to catch fish in the orient
3. Frigate birds
a. large soaring bird that specialize in "stealing" food from other sea
birds
d. Order Chadriiformes - Gulls and Terns
1. Gulls
a. predators and scavengers
b. widespread and common, numerous species
Local examples include the Herring Gull and the Laughing Gull
2. Terns
a. smaller than gulls
b. graceful, plunging birds specialized for catching small fish
c. The Arctic Tern breeds in the Arctic and travels 10,000 miles to summer
in the Antarctic each year
3. a related group, the Puffins, are the ecological equivalent to Penguins
in the Northern Hemisphere
e. Order Ciconiiformes - Herons
IV. Marine mammals - Class Mammalia
A. General
1. Characteristics of mammals
a. warm blooded homeotherms
b. hair
c. feed young with mammary glands
d. viviparous - give live birth
e. have a specialized tissue connection between the mother and developing
fetus called a placenta
f. Most marine forms have a blubber layer
g. Deep diving species show "mammalian diving reflex"
1. heart beat slows
2. blood is shunted preferentially to brain and essential organs
3. lungs collapse at depths
2. Taxonomy and characteristics
for Class Mammalia , marine groups
a. Order Pinnipedia - Seals and Sea Lions
1. most closely related to Order Carnivora - all are predators
2. Seal characteristics: 19 species
a.no external ears
b.posterior flippers are most developed for swimming and cannot rotate
forward
c. no external testes
3. Sea Lion characteristics: 5 species of Sea Lion an d9 species of related
Fur Seals
a. external ears
b. pectoral flippers are the most developed
c. both pectoral and pelvic flippers can rotate to carry weight
d. external testes
4. Important examples:
a. Monk Seals - live in warmer waters - Caribbean Monk Seal was last seen
in 1952 - presumed extinct
b. Crabeater Seal - interlocking teeth specialized for filter feeding on
krill
c. Elephant Seals - largest species - 20 feet and 4 tons
d. Harp seals - heavily hunted for the white fur of pups
e. Fur seals (sea Lions) all heavily hunted for fur industry - Northern
Fur Seal almost hunted to extinction
f. Walrus - heavy tusks - feeds mainly on benthic invertebrates
b. Order Carnivora - the Sea Otter - Enhydra lutris
(sometimes Polar Bears are considered marine)
1. true carnivore - feed on abalone. sea urchins, crabs, etc.
2. smallest marine mammal - 80 lb. max
3. lack blubber layer
4. almost extinct by 1911 - comeback since international agreement
5. intelligent - rudimentary tool use
6. Pacific coast from Siberia to California in kelp beds primarily
c. Order Sirenia - Manatees and Dugong
1. no hind legs or flippers
2. paddle shaped horizontal tail
3. fleshy lips for grazing on sea grass and other vegetation
4. all herbivores
5. heavy blubber layer
6. West Indian Manatee is the species found in Florida estuarine waters
7. Largest was the now extinct Steller's Sea Cow at 25 feet
8. only three species of Manatee, all endangered
9. All heavily exploited for blubber and oil historically
10. Dugong are strictly marine and numbers are critically low
d. Order Cetacea - Whales, Dolphin and Porpoise
1. General:
a. largest group of marine mammals
b. most completely adapted to marine life
c. stream lined bodies
d. tails evolved into flukes
e. loss of pelvic limbs - pelvic girdle is vestigial
f. front limbs evolved into flippers
g. nostrils moved to the forehead = blow hole
h. evolutionary ancestors were predatory land mammals with 4 legs
1. Archeocetus, Ambulocetus, and Pakicetus are important fossil ancestors
i. thick blubber layer for energy storage and insulation
j. many, if not all, evolved echo location for sensing their environment
k. all severely impacted by whaling and exploitation for meat and blubber
(whale oil)
1. oil used in cosmetics, margarine, mechanical lubricants, perfume
2. meat still prized in some countries
3. whale bone (baleen) was used heavily in fashion
l.Whale sizes:
1. Sperm whale Physeter macrocephalus Up to about 60 feet (18 meters)
long
2. Killer whale Orcinus orca Up to 30 feet (9 meters) long
3. Baird's beaked whale Berardius bairdii Up to 40 feet (12 meters)
long
4. Pilot whale Globicephala melaena Up to 21 feet (6 meters) long
5. Narwhal Monodon monoceros Up to 17 feet (5.2 meters) long
6. Beluga Delphinapterus leucas Up to 17 feet (5.2 meters) long
m. many form social and family groups called pods
1. social pod behavior is most highly developed in the toothed whales
2. example: Orca pods and the details we discussed in class
a. family groups
b. co-operative hunters
c. play behavior
d. defense of pod members
e.dominance order - ruled by a matriarch
n. Very intelligent animals
1. curious
2. good problem solvers
3. show much co-operative hunting and care behavior
4. some are interactive with humans
2.
Baleen whales: Suborder Mysticeti
a. taxonomy for Suborder Mysticeti
1. Family Balaenidae - Right whale, Bowhead whale
a. Right whale is our most endangered due to being the "right whale" to
hunt since it floats when harpooned
2. Family Eschrichtidae - Gray whales Know migration routes for North hemisphere
populations
a. Gray whales are the only whales to bottom fed on buried invertebrates
3. Family Balaenoptera - Minke whale,Sei whale, Bryde’s whale, Blue whale,
Fin whale, Humpback whale
b. know migrations for Humpbacks in Northern Hemisphere
b. All have specialized filter feeding structures in the mouth made of
keratin protein called baleen
1. feed on schools of krill and smaller fishes
c. Blue whale is the largest Whale - record 110 feet
1. hunted to near extinction due to vast amounts of oil harvested
3. Toothed whales: Suborder Odontoceti - all with peg like teeth for catching
and holding prey
V. Know what the Marine Mammal Protection Act of 1972 is and what it means for conservation of all marine mammals.a. Family Physeteridae - 3 sp. Pygmy Sperm, Dwarf Sperm, Sperm whale4. Echo location - biological sonar
1. Sperm whales heavily hunted for spermaceti and ambergris used in perfume bases
2. Moby Dick was based upon an actual encounter with a Sperm whale
3. many show scars from Giant squid sucker teeth - one favorite prey
b. Family Ziphiidae - 7 sp. Baird’s Beaked whale, Northern Bottlenosed whale, North
Sea Beaked whale
c. Family Monodontidae - Narwhal, White whale
d. Family Delphinidae - Ocean Dolphins - 18 sp. In N. A. waters
1. Examples: Atlantic Bottlenose, Atlantic Common, Orca, Pilot Whales, Pacific Whitesided,
Risso’s, Atlantic Spotted -
e. Family Phocoenidae - porpoise Two species in N.A. waters:Harbor Porpoise and
Dall’s porpoise
1. similar to dolphins, but smaller, blunt heads, flattened spade like teeth, slow swimmers
a. Most highly developed in toothed whales
1. one nostril is adapted to sound production
b. Sound is emitted through a 'melon organ" on the fore head that focusses the sound beam
c. Sound reflected from the target and environment is received by the lower jaw which is
connected to the inner ear
d. teeth are in staggered position form one jaw to the next to aid in determining direction of returning sound
e. sound is also used for communication
1. whale song and individual identification (for example: each dolphin has it's own unique "whistle")
2.Pod communications - many have their unique songs and signature sounds.
f. there is some evidence that whales and dolphins may emit high energy "sound blasts" to stun prey fish
5. Beaching behavior:
a. many species strand themselves on shores
b.poorly understood, may be due to:
1. protective behavior towards a sick or stranded pod member
2. misinformation from echo location
3. confused migratory behavior
4. Know what "rubber whales" are and what they are used for