Vertebrates 11.1 - Swimming Flashcards Preview

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Flashcards in Vertebrates 11.1 - Swimming Deck (21)
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1

Primary and secondary swimmers

Primary have always swam, secondary have returned to water from an ancestor that was terrestrial

2

Primary and secondary swimmers examples

Primary: fish and aquatic amphibians; Secondary: sea turtles, penguins, alligators, pinnipeds, cetaceans.

3

Undulatory groups

Trunk and tail: Anguiliform, carangiform, thunniform, ostraciform. Undulatory with paired fins ok too.

4

Anguliform

use most of body in undulation. Eels

5

Carangiform

About half of body (caudal) undulates. Jack fish and alligator.

6

Thunniform

Use just the back part of the tail. Tuna. The best form of swimming, creates the least drag.

7

Ostraciform

Just the tail moves. Rest of body rigid. Boxfish.

8

Undulatory with paired or unpaired fins

Stingray, bowfin, seahorse

9

Oscillatory swimmers

More like paddling. Used paired fins or legs. Frogs, beaver, sea turtle, penguins, duck, swan, perch

10

Role of fins

Caudal: generally big, thrust. Others are for stability and direction.

11

Pitch

Movement up and down. In fish created by extending or flexing both fins on both side (pectoral and pelvic)

12

Yaw

Movement side to side. In fish created by extending one fin and flexing the other.

13

Rolling

Controlled with the dorsal and anal fins, provide stability.

14

Were ancient fish good swimmers?

Streamline, caudal fin ok. But lacking the dorsal fins and pectoral fins pretty weak, so not very good. Dermal armour heavy and not flexible

15

Problems with water locomotion

Drag, buoyancy, and specific heat (esp for secondary swimmers)

16

Overcoming Drag

Water is dense, so it creates drag. Fusiform shape helps. (rounded at front end, tapered at other). Mucous makes boundary layer (water interacts with it, less drag).

17

Slow vs fast swimming

Slow: frictional drag. Fast: eddies/vortices create pressure drag (acts like vacuum). To go fastest, need to minimize movements but provide enough thrust. Balance.

18

Buoyancy

Depends on density of the animal. Most will sink naturally, but most have mechanisms to overcome

19

Buoyancy mechanisms of chondrichthyes

Cartilage is less dense than bones. Lots of lipids in liver (squalene). Shape helps maintain buoyancy (tail thrusts down a bit, head gives a bit of lift), fins lift.

20

Buoyancy mechanisms of osteichthyes (ray fins)

Swim bladder. It’s a membraneous sac associated with blood vessels. Regulates amount of gas in it. Head and tail don’t really affect buoyancy.

21

Problems with specific heat of water

Ectotherms ok because their body temperature can fluctuate without problems. Endotherms (cetaceans, some birds) need core temperature to be constant, use subcutaneous fat.