303 Whales midterm

Question 1

Cetacean

Answer 1

whales, porpoises and dolphins

Question 2

Mysticete

Answer 2

whales with baleen

• newer, more advanced (evolutionarily speaking)
• “mustache” whales
• usually solitary, live alone

Question 3

Odontocete

Answer 3

toothed whales

• first whales, older, less advanced (evolutionarily speaking)
• usually social, live in groups

Question 4

Telescoping

Answer 4

• evolutionary process
• shows evolution from land animal to marine animal
• nostrils moving from front of face to top of head
• elongation of face
• helps animals breathe easier b/c it doesn’t have to lift it’s head, just has to graze surface to breathe

Question 5

Homodont

Answer 5

-all SAME teeth
-baleen
-found in larger cetaceans
-MORE evolutionarily efficient because they just swim thru water and filter feed on small, easily available prey
-uses so much less energy AND they gain more energy by eating “bottom-of-the-food-chain” animals - no energy lost thru trophic levels
(aka “optimal foraging”)

Question 6

Heterodont

Answer 6

• all DIFFERENT teeth
• toothed whales
• smaller cetaceans
• LESS evolutionarily efficient because they have to chase their prey and rip it up
• uses much more energy
• energy gains are not as much because so much energy lost thru trophic levels

Question 7

Blubber

Answer 7

• Fat layer under skin
• made of fat and connective tissue
• keeps them warm
• acts as huge energy reserves
• allows them to keep their fusiform body shape
• handy to help with compression of body under extreme pressure
• gives them density to help move thru water

Question 8

Vestigial

Answer 8

part of body that has no longer have a crucial evolutionary role
ex. our appendix

Question 9

Ventilation & Voluntary breathing

Answer 9

• breathing - whales must surface to breathe in air
• whales are “voluntary breathers”, not automatic like us
• this is why they NEVER sleep, because they have to breathe on command and would suffocate if they slept for too long
• able to push ALL air out of lungs - have special lining on inside that makes lung walls not stick together
• have myoglobin in blood - allows them to hold 4x more oxygen in blood than us (we just have hemoglobin)

Odontocetes: have one blowhole, one nostril
Mysticetes: have one blowhole, two nostrils

Question 10

Phylogenetics

Answer 10

The study of relatedness among forms

• similar body structures/characteristics, etc.
• example: finger bones in whale’s flippers and claw bones in land mammals

Question 11

closest common living ancestor

Answer 11

Hippo’s :)

Question 12

1. Pachayena

Answer 12

• earliest living land-dwelling ancestor
• carniverous predator
• coastal 4-legged mammal
• looked like short-legged panther dog

Question 13

2. Ambulocetus

Answer 13

-had early whale teeth
-“walking whale”
-lived on land but hunted in water
-webbed feet, smaller legs
~48 mya

Question 14

3. Rodhocetus

Answer 14

-more fusiform body shape
-first fossil evidence of fused lower spine
-still had fur
-longer tail
-looked like a crocodie/sea lion
~46 mya

Question 15

4. Basilosaurus

Answer 15

-very fusiform, longer body
-no back legs
-no fur
-lives in water completely
~37 mya

Question 16

5. Dorudon

Answer 16

-first development of tail flukes!
-first evidence of a blowhole!
-very sharp teeth (“spear tooth”)
-broad distribution of fossils
~33 mya

Question 17

6. Brygmophyster

Answer 17

-very round skull - first evidence of melon/echolocation!
-sternum bone not connected to ribs - evidence of diving very deep!
-still had teeth - “biting sperm whale”
~30 mya

Question 18

7. Diorocetus

Answer 18

-early baleen whale!
-bottom feeder
-very thin skull - first conformation of echolocation
~30 mya

Question 19

Modern day WHALE diversity

Answer 19

~88 species
5-100 feet long
-inhabit all oceans
-all out in ocean, not really anymore in rivers/inland waters

Question 20

Skeleton

Answer 20

• no bones in tail
• very flexible bones and ribcage
• fused vertibral column and sternum
• melon in head for echolocation
• lil finger/arm bones that form flippers

Question 21

Tail

Answer 21

• powerful and energy efficient propulsion system

- ligaments along spine “snap” tail upwards

Question 22

Integumentary System

Answer 22

AKA: skin
3 layers:
1. epidermis - outer layer
2. dermis - in between (kinda intertwined with blubber)
3 hypodermis - blubber

• NO sebaceous glands (do not excrete anything thru skin)
• constantly molting patches of skin
• usually have lots of lil parasites on epidermis
• sometimes have lil bristles on skin which act as sensors

Question 23

Mechanisms for Thermo-regulation

Answer 23

blubber
CCHE
Rete Mirable

Question 24

Ectoparasites

Answer 24

lil species that live on skin

-some have medicinal purpose are are beneficial to whale

Question 25

Brain

Answer 25

• largest brain out of all animals (in terms of brain to body size, aka incepalization quotient)
• has folds - allows for more cognitive functioning
• have specialized functions

Question 26

Circulation System - Selective warming, CCHE & aortic bulb

Answer 26

can shut off circulation to certain areas of body to save energy

• have “Aortic Bulb” - lil muscle on heart that “super-pumps” the heart in order to get it flowing to entire body
• CCHE: counter-current heat exchange - allows them to not pump blood into extremeties and keep it all in the core - very energy effecient

Question 27

Sight

Answer 27

• large eyes but not great eyesight
• sclera is very rigid so they dont pop under pressure
• primary sense for sight is echolocation

“spyhopping” - when whales lift their head/eyes above the water - believed to be so they can check out whats around on the surface

Question 28

Smell/Taste

Answer 28

-lost majority of taste receptors and all of olfactory (smell) receptors

Question 29

Hearing

Answer 29

• no external ear openings

- there’s a space with soft tissue and a few conductive bones

Question 30

Baleen

Answer 30

*made out of keratin - same stuff our fingernails are made of

Question 31

Feeding methods

Answer 31

1. Engulfing: opens mouth, sucks all water and food in, shuts mouth, pushes/filters all water out thru baleen
2. Skimming: sucks in water/food thru baleen, catches small organisms in baleen/mouth
3. Lunging: gathering prey near surface (bubble-netting) and then lunging thru it with mouth open
4. Suctioning: suck in sand/bottom sediment and then pushes out water and sand/keeps prey in mouth

Question 32

Stomach & Digestion

Answer 32

• multi-chambered stomachs that contain fermentation bacteria
• have tough stomach walls to handle plant digestion
• have very acidic stomachs to break down animal meats
• have rocks in forestomach to help grind up foods
• shut down digestive system while diving to save energy and handle pressure better

Question 33

Sperm whale’s head

Answer 33

• 1/3rd of body is their head
• largest brain out of any animal
• different groups have different dialects of clicks

Question 34

Spermecete

Answer 34

• oil contained in a sack in sperm whale’s head
• makes up about 1/4th of their body
• helps amplify click sounds
• buoyant when liquid and sinks when solid: helps whale dive/rise
• whales can control temp of spermecete sack

Question 35

monkey lips

Answer 35

lil organ inside sperm whales head

• looks like a pair of lips
• this is what makes the click sound
• can make clicks up to 230 decibles

Question 36

Hydrodynamic state

Answer 36

-organs are stored deep within body cavity so their shape stays streamline

Question 37

incephalization quotiant

Answer 37

ratio of body size to brain saize

Question 38

Rete Mirable

Answer 38

cluster of blood vessels that heats cooler blood from extremeties USING warm blood form core
-very efficient heating system, no extra energy expended to heat blood

Question 39

Brachycardia

Answer 39

can slow heart rate voluntarily