6a: Propulsion, swimming and locomotion

Question 1

Propulsion/Swimming/locomotion:what purpose does the skeleton serve to accomplish?

Answer 1

key role in how each species of marine mammal moves on land or in water

Question 2

Pinniped propulsion:

describe how the different species of pinnipeds move through water?

Answer 2

different species of pinnipeds have distinct differences when moving through water

Question 3

Cetacean swimming:

What muscles contribute to downstroke?

Answer 3

utilizes epaxial muscles to extend the caudal fin upwards.

1. mulifidus extensor
2. longissimus extensor

Question 4

Cetacean propulsion:

caudal fin: divided into 4 components name and describe them (also be able to spot them in pic)

Answer 4

1. outside or cutaneous later
2. thin blubber layer than any other part of the body
3. layer containing ligaments that extends from the caudal keep and sides of the caudal fin
4. flukes inner core made up of touch, dense fibrous tissues with an envelope of ligaments. Within this are numerous BV arranged to act as heat retaining countercurrent system

Question 5

Propulsion/Swimming/locomotion:
cetaceans
caudal fins

Answer 5

movement through water is with these, and are divided into 2 flukes

Question 6

Pinniped propulsion –> Phocids

1. what type of movement do they do?

Answer 6

lateral motion using hind flippers (side to side)

use webbing between toes to move more water (creating thrust) use fore flippers as paddles for steering

Question 7

Cetacean propulsion:

what determines the shape of the caudal fin?

Answer 7

varies between cetaceans, depending on the power required to move the animal

Question 8

Cetacean swimming:

What muscles contribute to downstroke?

Answer 8

utilizes hypaxial muscles that flex the caudal fin and depress the flukes
1. flexor caudae lateralis
flexor caudae medialis

Question 9

Propulsion/Swimming/locomotion:

Sirenians body design

Answer 9

move only through water

uses caudal fin to move through water

Question 10

Sea otter propulsion:

What are the two methods of moving through water?

Answer 10

1. pelvic paddling (surface) 
pelvic undulation (diving)

Question 11

Cetacean propulsion:: humpback whale;

describe the location and purpose of the tubercles on their pectoral fins?

Answer 11

on anterior edge of find

act as lifting devices

Question 12

Sea otter propulsion:

VDU?

Answer 12

• pelvic paddling
• head and scapular region are kept above water
• only hide limbs are used to move the animal through water with the fore feet held across the chest
• hind lies may move simultaneously or alternatively
• used for swimming place to place in pre to dive or swimming submerged at high speeds.

Question 13

Propulsion/Swimming/locomotion:

Pinnipeds body design

Answer 13

• movement on land and through water

uses paired fore and hind flippers

Question 14

Sea otter propulsion:

VSUD

Answer 14

• pelvic paddling
• swimming is normally associated with grooming behaviours
• otter will roll along the axis of the body as it moves along
• only the hind paws provide the propulsion during this behaviour

Question 15

What has changed in the fore and hind lies of marine mammals to aid in propulsion in aquatic environments and land if relevant

Answer 15

decreased in length but increased in SA

Question 16

Cetacean swimming:

What major groupings are responsible and where are they found

Answer 16

alternating the action of the epaxial and by-axial muscles (found long the lumber and caudal regions)

Question 17

Cetacean swimming:

describe what is unique about how cetaceans use their caudal fin and flukes for propulsion that conserves energy

Answer 17

the use elates band to power their caudal fin instead of metabolically producing energy. Strong elastic CT found in their flukes helps to transmit the propulsive forces while swimming. Tendons and CT sheath (in flukes), energy is stored as elastic strain E and is recovered as recoil.

Question 18

sirenian propulsion: caudal fin

1. shape of manatees vs. dugongs?
2. uses
3. propulsion method used and mechanics

Answer 18

1. manatee= broad flat caudal fin; dugong = caudal fin with flukes
2. slow but capacble of powerful thrusts (when wanted); caudal oscillations to propel them
3. propulsion: upward movement of caudal fin then downward swing.
   osciailation causes the body to displaced i na vertical manner (body up and down)
   caudal fin is also used to steer, bank or roll over`

Question 19

What is propulsion

Answer 19

a force causing movement

Question 20

Cetacean propulsion:
Caudal fin–>
What structure is found in the middle of the caudal fin but not actually a part of the fluke?
2. whats its function?

Answer 20

1. compressed vertebrae

2. acts as a supportive structure of the caudal fin

Question 21

Sea otter propulsion:

VSU?

Answer 21

ventral surface up swimmign

• type of pelvic paddling
• body is partially submerged with the chest and head above the water
• fore feet are normally folded on the chest with alternating simultaneous stokes of the hind limbs
• some may raise both hind limbs above ware and move the tail in a lateral motion
• type of swimming is used when the otter is feeding or as the first step to evade from disturbances.

Question 22

Sea otter propulsion:

Pelvic undulation

Answer 22

• sued for propulsion when diving

- achieved by vertical flexing of the vertebral column

Question 23

Cetacean propulsion::

describe what is unique about pectoral fins on a humpback whale? and what is the reason?

Answer 23

have become adapted for high maneuvering during feeding; because they are long and narrow

Question 24

Cetacean propulsion:;

What percent of its body length are these pectoral fins in humpback whales?

Answer 24

25-35 percent of its total body length

Question 25

Propulsion/Swimming/locomotion: Compare flippers to caudal fins

Answer 25

paired flippers is slower but more efficient; allows for more rapid turns and movements aural fins with flukes are more powerful, but slower to make turns or loops

Question 26

Cetacean propulsion: | What allows them to move through water in an efficient manner

Answer 26

pectoral fins

Question 27

Pinniped propulsion --> Phocids | advantages and disadvantages

Answer 27

Ad: more stable dis: less fast than otariids

Question 28

sirenian propulsion: pectoral flippers 1. what is the shape? 2. how used by adults vs. young during swimming vs. during floating or along bottom?

Answer 28

1. flat paddle like front pectoral flippers; usually kept close the body 2. young --> swim only using pectoral flippers floating --> used for spinning and turning their bodies also used for walking along the bottom of their environment

Question 29

Propulsion/Swimming/locomotion: cetaceans fore limbs = pectoral fins

Answer 29

- evolved vestigial hind limbs | - evolved to have forelimbs with elbows leading to a wrist and fingers that have become pectoral fins (Non flexible)

Question 30

Pinniped propulsion --> Otariids | What is power/paddle/recover cycle? and explain it

Answer 30

1. is used to create the powerful forward thrust through water rotate the flipper --> push it forward --> pull it backwards towards the body

Question 31

Propulsion/Swimming/locomotion: General principles What key role does the skeleton play?

Answer 31

skeleton determines body size and attachment points for tendons and ligaments

Question 32

Pinniped propulsion --> Odobenids (walrus) what kind of swimming pattern for locomotion 2. explain

Answer 32

1. pelvic oscillation (hind limb swimming) for locomotion) | 2. hind flippers = propulsion; fore flippers = steering

Question 33

sea otter propulsion: 1. Explain pelvic paddling. 2. what do they use to do this? (3 modes of movements)

Answer 33

1. occurs at the surface and uses the hind limbs for propulsion 2. a) ventral surface up swimming (VSU) b) ventral surface down swimming (VSD) c) Alternating ventral surface up and down swimming (VSUD)

Question 34

Cetacean propulsion:: | how have pectoral fins been altered?

Answer 34

elbow is nar their bodies | what is seen moving consists of almost entirely of what is the fore arm and hand (in terrestrial mammals )

Question 35

Polar Bear propulsion: | What physiological adaptions they have for swimming?

Answer 35

they have developed strong limbs with feet that form flat plates--> distribute their weight when walking over snow - use crawling action to move through water, hind limbs trailing. To accodate, their forelimbs have rearranged some muscles which help them to pull themselves .

Question 36

Pinniped propulsion --> Phocids 1. what kind of swimming pattern? 2. explain

Answer 36

``` pelvic oscillation (hind limb swimming) for locomotion 2. hind flippers = propulsion fore flippers = steering ```

Question 37

Pinniped propulsion --> Otariids 1. what kind of swimming pattern? 2. explain how they move

Answer 37

1. pectoral oscillation (or forelimb swimming) 2. move their large pectoral fore flippers similar to how birds use their wings. Fore flippers or forelimbs have almost 2x the SA than their hind (pelvic) flippers

Question 38

Describe different body designs evolved to compensate environment? (terrestrial vs. marine)

Answer 38

Terrestrial: heavy body skeleton; long/thin or short/thick legs depending on predator or prey Marine: long and slender body shape except polar bear.

Question 39

Cetacean swimming: 1. Describe the style of swimming? 2. what is it called?

Answer 39

1. complex flexing and extending of several muscles , which moves the caudal fin up and down and flexes the fluke inward and outward 2. caudal oscillation

Question 40

Propulsion/Swimming/locomotion: | sea/river otters & polar bears

Answer 40

almost move on both land and water | move using hind and forepaws.

Question 41

Pinniped propulsion --> Otariids | Advantages and disadvantages of this type of stroke?

Answer 41

ad: fast swimming and ability to do tight turns dis: instability in trajectory