Marine Mammals Flashcards
List five physical characteristics unique to marine mammals
o streamlining of body shape
o limb modifications as flippers, disappearance of hind pair in some groups
o thermal regulation
o modified respiratory system - diving adaptations
o osmotic adaptations - impervious skin, efficient kidney, don’t drink much seawater
State five characteristics that enhances marine mammals’ ability to thermoregulate.
large size low surface to volume ratio thick skin blubber reduced peripheral circulation (blubber with few blood vessels) higher metabolic rate
Mysteceti (Baleen Whale) characteristics:
- Baleen plates present (lack teeth)
- Paired external nasal openings
- Small sternum, few ribs, can’t withstand beaching
- Communicates by series of moans, squeaks and screams
Odontoceti (toothed whale) characteristics:
- Teeth present (lack baleen)
- Single external nasal opening
- Long and robust sternum, can withstand beaching
- Communicates via whistles and echolocation
Odontoceti (toothed whale) communication:
- Whistles and echolocation (emitting rapid sounds, usually clicks, into blind areas and measuring the time these sounds take to travel to and from an object.
What is the whale bone?
- Baleen
- Specialized, keratinized epithelial tissue
- arranged in a series of 100-400 plates
- Form a comb on each side of the mouth (in place of teeth)
Describe the migration patterns of baleen whales
- Highly migratory
- High latitude feeding areas in summer (polar)
- Low latitude calving areas in winter (tropical)
- 3000 to 5000km each way
- Gray whales migrate 10000km each way
How do baleen whales feed?
- Filter seawater
- To trap krill, copepods, amphipods, and small fish
- Use suction of tongue to palate to draw water in and opposite movement to force water out
What species belong to the Rorqual family (5)?
Blue Whale Fin Whale Humpback Whale Minke Whale Sei Whale
What are the distinguishing characteristics of the Rorqual family?
- Longitudinal grooves on throat
- Small pointed dorsal fin
- Largest whales on earth
What species belong to the Grey Whale family?
- Grey whale
What are the distinguishing characteristics of the Grey whale family (4)?
- Small dorsal hump
- 10-12 knobs on dorsal ridge
- Parasitic barnacles on their skin
- Unfused neck vertebrae
How do Grey Whales feed and explain their migration pattern?
- Bottom feeders, suck up large amounts of sediment and filter out crustaceans
- Do not feed during breeding season
- November to early december begin migrating south to Baja
- February to early may they begin migrating northward again
- Migration is 10000km
What species belong to the Balaenidae family?
- North Pacific Right Whale
What are the distinguishing characteristics of right whales (4)?
- No dorsal fin
- No throat grooves
- Extremely long baleen plates
- Hugely arched jaw
Why are they called ‘right’ whales?
- got its name from whalers who thought it was the “right”
whale to hunt, contains a huge amount of oil and baleen
How do right whales feed?
- has black baleen plates up to 2.8 meters long, which it uses to catch copepods and krill near the surface. This feeding
strategy is known as skimming.
What are the distinguishing characteristics of Odontoceti (Toothed Whales) (5)?
- Single nasal opening
- Fat melon behind face?
- up to 220 teeth
- marked asymmetry of surrounding bones
What families belong to the suborder Odontoceti (4)?
- Delphinidae (Dolphin family)
- Phocoenidae (Porpoise family)
- Ziphidae (Beaked whale family)
- ## Physteridae (Sperm whale family)
Characteristics of dolphins
- Bulging forehead
- Teeth are unlobed
- Usually curved dorsal fins
- Sleek, streamlined bodies
- Distinct beak
- Deep tail notch and ridge on top of tail
Characteristics of porpoises
- Lack a well-formed beak
- Blunt snout
- Stocky body
- Teeth are spade shaped
Who are the “Ziphids”? What are their unique physical features?
Beaked whales:
- Long narrow snout
- Small and ovate pectoral fin
- Dorsal fin is small and sickle shaped
- Pair of grooves on the throat, form a V at the chin
- Few teeth (2-4)
What are the unique features used to identify the sperm whale family (6)?
- Broad, flat rostrum
- Great depression on facial part of skull - accomodates spermaceti
- S-shaped blowhole located on left side of snout
- Numerous short grooves on throat
- Functional teeth only in lower jaw
- A left nasal passage for respiration, right one for hearing
Breaching
- When a whale launches itself in the air head first and lands on water with a splash
- Not known why, could be courtship, dislogging parasites, fun etc.
Spouting
- When a whale comes to surface to expel moist air from lungs and intake fresh air
Podding
- Herding behavior during the breeding season and migration
Describe porpoising
- Moving in and out of the water in a series of high speed leaps
- For momentum, speed, corraling fish, breathing
Spy-hopping
- When cetaceans use their tails to hold themselves out of the water “tread water”
- For looking at surroundings
Flipper slapping
- When cetaceans slap their flippers on the surface of water
lobtailing
Same as flipper slapping but with their fluke. used for aggression or fun
Compare and contrast resident and transient killer whales
Resident:
- Feed on fish
Transients:
- Feed on marine mammals
Northern Pacific right whales natural history
- Slow swimming
- Extremely endangered
