Wee 5

Question 1

!Cetaceans most closely related to

Answer 1

Hippos

Question 2

!Two sub order

Answer 2

Odontoceti - toothed whales

Mysticeti - baleen whales

Question 3

Mysticeti Vs Odontoceti teeth

Answer 3

*Mysticeti:
Plates of baleen used to siv food out of water
*Odontoceti
Have teeth

Question 4

!Cetacea general skull morphology

Answer 4

Relatively large brains
Elongated rostrum
Nasal opening is set far back on the top of the skull, posterior to the orbits.

Question 5

!Cetacea general skeleton

Answer 5

Separate cervical vertebra allow flexibility in roequals, river dolphins & belugas
Front limbs modified into flippers
Odontoceti hind limbs are absent. Mysticeti hind limbs and pelvic girdle are vestigial.

Question 6

!Cetacea other characteristics

Answer 6

Streamline body shape
Lack external ears
Penis and testes internal
& Teats in slits either side of the genital area
Horizontal tail fin that moves in the vertical plane

Question 7

!Cetacea blubber and skin

Answer 7

Good at thermoregulation:
Counter-current heat exchangers which can be overridden in warmer waters to dumb heat
Turbulence reduction

Question 8

!Cetacea adaptation to prevent against the bends

Answer 8

Their already small lungs compress when diving which forces any air into the trachea & bronchus. No nitrogen can be absorbed into the blood which means bends can’t happen

Question 9

!First recognisable cetaceans was when?

Answer 9

Early middle Eocene

Question 10

!Cetaceans basic evolution

Answer 10

Decline in reptiles, due to the change in climate to colder waters, led to an incline in cetaceans.
Resource pressure led to the adaptation of eating fasted moving fish.

Question 11

!Platanistidae

Answer 11

Ganges and Indus dolphins

Question 12

!Platanistidae: Ganges and Indus dolphins swimming style

Answer 12

Side swimmers

Question 13

!Platanistidae: Ganges and Indus dolphins skull and dentition adaptations

Answer 13

Differential teeth:
Front half of the skull is classic conical dolphin teeth where the rear teeth have flanges on either side of the crown that are modified to crush hard bodied prey (crabs, turtles, armoured catfish).
Skull adaptations to help channel the returning sound waves

Question 14

!Platanistidae: Ganges and Indus dolphins: human interaction

Answer 14

Caught as by catch

Question 15

!River dolphin general characteristics

Answer 15

Poor eyesight due to murky waters

Longitudinal slit blowhole

Question 16

!Who has the longest beak of any cetacean?

Answer 16

Pontoporiidae: la Plata dolphin

Question 17

!Pontoporiidae: la Plata dolphin human interaction

Answer 17

Hunted for meat oil and leather
Fishes for eating
Caught as bycatch

Question 18

!Delphinidae melons

Answer 18

Organ on the top of head which helps focus sound pulses to pick up prey location.

Question 19

!Delphinidae blowhole shape

Answer 19

Crescent

Question 20

!Delphinidae brains

Answer 20

Relatively large.

Large surface area of the cerebral cortex from information processing and storage.

Question 21

!Delphinidae behaviour

Answer 21

Intraspecific fights

Rape between male:female and male:male

Question 22

!Dolphin & porpoises taxonomy explained

Answer 22

They are sister taxa sharing a common ancestor

Question 23

!Phocoenidae (porpoises) morphology:

Answer 23

Single blowhole
Melon on forehead
Lack a rostrum, long beak instead

Question 24

!Phocoenidae (porpoises) Dentition

Answer 24

Teeth are laterally compressed and spatulate compared to the dolphins conical shape

Question 25

!Phocoenidae (porpoises) other characteristics: * Tail * Testes * Fins

Answer 25

*Tail stocks at end of tail which laterally compress into keels. *Testes Swell to 4% BM in breading season. Suggested sperm competition. *small triangular fins

Question 26

Phocoenidae (porpoises) human interaction

Answer 26

Habitat degradation from dredging and trawling. By-catch Hunted by Japanese

Question 27

Monodontidae (beluga and narwhal) Narwhal teeth and tusks

Answer 27

2 functional teeth. Females: don't protrude from the gum-lime. Males both grow into tusks. 1% of males have 2 tusks 1% of females have a tusk Used for sensory capabilities and male combat

Question 28

``` Monodontidae (beluga and narwhal)other characteristics Fin Neck Tail Blubber Sounds ```

Answer 28

Lack a dorsal fin Flexible necks to turn heads sideways Mobile flippers to aid manoeuvering and swim backwards Tail shape changes with age in male narwhals. Tips migrate forwards Thick blubber to protect against architect waters Belugas produce a wide variety of sounds while narwhals are almost silent

Question 29

Monodontidae (beluga and narwhal) human interaction

Answer 29

Hunters and human disturbances

Question 30

Physteridae (sperm whale) morphology * Head * Nasal

Answer 30

``` *head Bulbous forehead which holds the spermaceti organ. Could act like a melon or buoyancy. *Nasal Asymmetric nasal passages: Left: breathing Right: Sound production ```

Question 31

Physteridae (sperm whale) dentition

Answer 31

Rod-like lower jaw containing 20-26 pairs of teeth. | Teeth might not be used for feeding because well fed sperm whales are found without teeth or lower jaws

Question 32

Physteridae (sperm whale) feeding

Answer 32

Deep sea squid Males eat more than females Make repeated foraging dives

Question 33

Physteridae (sperm whale) other characteristics: Skin Fin

Answer 33

Skin corrugated except head and tail flukes | Low dorsal fin

Question 34

Physteridae (sperm whale) human interaction

Answer 34

Hunted for spermaceti, oil, blubber, and meat

Question 35

Kogidae (pygmy and dwarf sperm whale) teeth

Answer 35

Only lower jaw carries teeth | Dwarfs have 3 vestigial teeth in the upper jaw

Question 36

Kogidae (pygmy and dwarf sperm whale) other characteristics: Head Discharge

Answer 36

Head more conical and shorter Shark-like appearance Discharge a red/brown fluid from there intestines when threatened

Question 37

Ziphiidae (beaked whale) skull morphology | Tusks

Answer 37

1 or 2 sexually dimorphic tusks | Females and juiveniles functionally toothless

Question 38

Ziphiidae (beaked whale) human interaction

Answer 38

Chemical and plastic pollution | By catch

Question 39

Mysticeti (baleen whales) general body size

Answer 39

Small SA to V ratio means less heat loss. Larger bodies can store more fat

Question 40

Mysticeti (baleen whales) skull morphology

Answer 40

Frontal, rostral & cranial bones have fused Jaws extended Upper jaw supports baleen plates

Question 41

Schrichtiidae (gray whales) feeding

Answer 41

They strain bottom sediments for organisms. Association with sea birds in that when the whale comes to the surface the birds eat the crustaceans that they bring along with them from the sediment.

Question 42

Schrichtiidae (gray whales) human interaction

Answer 42

Whale watching is economically important

Question 43

Balaenoptera (Roequals) skull morphology

Answer 43

*Central ridge between blow-hole and snout *Lower jaw bowed & protrudes beyond end of snout Bird-like

Question 44

Balaenoptera (Roequals) Human interaction.

Answer 44

Hunted for blubber, oil and meat. Climate change Marine pollution

Question 45

Balaenidae (right whales) skull morphology Head Callosites

Answer 45

Arched rostrum Absence of throat grooves Callosites: thickened skin patches form along the rostrum and lower jaw. They are larger in males. Houses colonies of white lice. May be for scraping skin in conflicts or as individual ID.

Question 46

Balaenidae (right whales) human interaction

Answer 46

Mortality from: collision with shipping Entanglement in fishing gear

Question 47

Neobalaenidae (pygmy right whale) morphology

Answer 47

Similar to right whales 2 clearly marked throat grooves similar to gray whales Small triangular dorsal fin which is absent in right whales