Cetaceans

Question 1

Can you name the two sub orders of cetacea?

Answer 1

Odontoceti - toothed whales.
Mysticeti - baleen whales.

Question 2

Can you name the 10 families that make up odontoceti?
BQ: Which is believed to be extinct?

Answer 2

Lipotidae - yangzee river dolphin.
Iniidae - amazon river dolphin.
Platanistidae - ganges and indus dolphin.
Pontoporiidae - la planta dolphin.
Delphinidae - dolphins, pilot and killer whale.
Phocoenidae - porpouses.
Monodontidae - beluga and narwhal.
Physteridae - Spermwhale.
Kogidae - dwarf and pygmy sperm whales.
Ziphiidae - beaked whales.
BQ: Lipotidae.

Question 3

Can you name the 4 families that make up mysticeti?

Answer 3

Eschrichtiidae - grey whales.
Balaenopteridae - rorquals.
Balaenidae - right whales.
Neobalaenidae - pygmy right whale.

Question 4

Can you name the largest and smallest cetacean?

Answer 4

Largest - blue whale.
Heavisdides dolphin.

Question 5

Can you describe their lifestyle and diet?

Answer 5

Aquatic.
Most species are marine (some freshwater).
Carnivores, piscivores, squid and krill specialists.

Question 6

Name 3 skull characteristics.

Answer 6

Large brains.
Most have elongated rostrum.
Nasal opening is set far back at top of skull (prosterior to orbits.

Question 7

Name 4 skeletal adaptations.

Answer 7

1. Seperate cervical vertebrate allow flexibility in rorquals, river dolphins and belugas.
2. Other species have 2-7 fused cervial vertebrae.
3. Front limbs retained and modified into flippers.
4. Odontocetes - hind limbs absent (mysticetes only vestigal hind limb and pelvic gridle).

Question 8

Name 6 other morphological adaptations.

Answer 8

1. Streamline in shape.
2. Lack external ears - tiny openings.
3. Penis and testes internal.
4. Teats housed within slits eitherside of genetal area.
5. Only protuberances (horizontal pair of flippers, boneless tail fluke, boneless fiborus dorsal fin (not all spp)).
6. Horizontal tail moved vertical plane.

Question 9

Name 2 functions of blubber and skin in cetaceans.

Answer 9

Thermoreculation.
Turbulance reduction.

Question 10

Name 4 diving adaptations.

Answer 10

1. Small lungs compress on dive.
2. Air forced into trachea and bronchus.
3. No nitrogen to be absorbed into blood.
4. No risk of bend.

Question 11

Which epoch did ceteceans appear?

Answer 11

Middle Eocene

Question 12

Mysticeti.
Why are they so big?

Answer 12

Being bigger prevents heat loss and provides fat storage.

Question 13

Name 3 skull characteristics.

Answer 13

1. Supraocccipital regions moved forward over frontals and rostral and cranial bones have fused.
2. Jaws greatly extended.
3. Rostrum (upper jaw) supports baleen plates.

Question 14

Mysticeti.
What family do grey whales belong to?

Answer 14

Eschrichtiidae.

Question 15

Mysticeti.
Name 3 characteristics of Eschrichtiidae.

Answer 15

1. Moltted grey with patches of barnicales and whale lice.
2. Spout, paired, short and bushy.
3. Longest mammalian migration.

Question 16

Mysticeti.
How do Eschrichtiidae feed?

Answer 16

Strain bottom sediments.
May also take planktonic prey from the water column and some fish.

Question 17

Mysticeti.
What whales belong to balaenoptera?

Answer 17

Humpback.
Fin.
Sei.
Brydes blue.
Blue.
North and south mike whales.

Question 18

Mysticeti
What whale belongs to balaenidae?

Answer 18

Right whales.

Question 19

Name 3 skull characteristics in balaenidae.

Answer 19

1. Arched rostrum.
2. Long slender baleen plates.
3. Absence of throat grooves.

Question 20

Mysticeti.
What whale belongs to neobalaenidae?

Answer 20

Pygmy right whale.

Question 21

Mysticeti.
What are 3 morphological characteristics of neobalaenidae?

Answer 21

1. Similar to right whales.
2. 2 clearly marked throat grooves.
3. Small triangular dorsal fin (absent in right whales).