Pinnipedes

Question 1

Give the phylogenetic position of the pinnipeds.

Answer 1

In the order Carnivora

Closely related to Mustelids and Ursidae

Question 2

Give the 3 families contained within the pinnipedes

Answer 2

Odobenidae- Walrus
Otariidae- Eared seals
Phocidae- True seals

Question 3

Give the use of a walruses tusks and on which sex they are found

Answer 3

Both sexes
Used to battle between males
Protection from predation
Haul themselves onto ice

Question 4

How is the Odobenidae adapted for feeding ?

Answer 4

Walrus skull is specialised fro feeding on clams and other benthic invertebrates

Question 5

Give the 2 main groups of eared seal.

Answer 5

Fur seals and Sea lions

Question 6

Which flippers of the eared seals have a key role in propulsion in water ?

Answer 6

Large fore flippers

(hind only for steering

Question 7

Why are eared seals more agile than True seals on land ?

Answer 7

Can support weight on foreflippers

Hind flippers turn inwards to enable walking

Question 8

Which flippers of the eared seals have a key role in terrestrial locomotion ?

Answer 8

Both fore and hind flippers

Question 9

On which family is a pinna found ?

Answer 9

The Otariidae, Eared seals

Question 10

Where is the muscle mass found in the family Otariidae ?

Answer 10

Eared seals, At the front of the body

Question 11

Which flippers do true seals use for swimming ?

Answer 11

Hind flippers

Question 12

Where is the muscle mass found in the family Phocidae

Answer 12

True seals, the rear of the body

Question 13

Give the distinguishing deatures of the Grey seal.

Answer 13

Roman nose

Parrallel shaped nostrils

Question 14

Give the defining features of the Common Seal

Answer 14

Flat faced

V shaped nostrils

Question 15

Give some sensory adaptions of seals

Answer 15

Good vision on land and sea
Higher vocal repertoire
Can hear higher frequencies
Click vocalisations- Echolocation ?

Question 16

What is delayed implantation ?

Answer 16

A fertilised egg will remain as a blastocyst till its ready to attach to the uterine wall.

Question 17

Give a collective group within the pinnipeds that exhibit delayed implantation.

Answer 17

Seals

Question 18

What is the advantage to a seal of delayed implantation ?

Answer 18

Condenses breeding season on land (most vulnerable)

Enables birth of pup when environmental conditions ideal

Question 19

Elephant seals defend matin beaches, what does this enable ?

Answer 19

Alpha male can exhibit Polygyny

up to 100 females a season

Question 20

Describe the morphology of elephant seals.

Answer 20

Huge proboscis

3 times the mass of the female

Question 21

How do male elephant seals establish territory ?

Answer 21

Participating in Bloody fights for dominant position on

Question 22

How many pups will elephant seal females produce in a 12y lifetime

Answer 22

14 pups

Question 23

What happens to subdominant male elephant seals ?

Answer 23

Hang around the edges of the mating beaches and intercept females as they return to the sea.

Question 24

Male elephant seals (bulls) are very aggressive, give examples of this ?

Answer 24

Will attempt to mate with pregnant females

Trample pups

Question 25

Describe a key difference in male and female elephant seal pups

Answer 25

Will steal milk from females to grow bigger