Marine Vert. -- ppt 2 (Swimming)

Aquatic animals have to overcome the force of …

drag

Terrestrial animals have to overcome the force of …

gravity

Frictional drag

friction between water and surface

What is frictional drag determined by?

smoothness (mucus production and scale shape) and surface area (body, fin shape)

T/F Frictional drag increases with velocity.

True

Pressure drag

pressure differences caused by movement

What is pressure drag determined by?

body shape

Does pressure drag increase with velocity squared?

yes

What is the muscle called that help with motion?

myomeres

What do anguilliforms use for motion?

truck and tail undulations

What are some examples of anguilliforms?

eels, dogfish, elongate sharks, larvae

T/F The head contributes to forward motion in anguilliform.

False—everything but the head is used for propulsion.

Are anguilliforms relatively slow or fast? why?

-slow due to long body

-inefficiencies of high lateral thrust

-large cross section

T/F Anguilliforms are very flexible.

True

What part of the body undulates in subcarangiform swimming?

posterior ¾ - ½ of body undulates

What are some examples of subcarangiform swimmers?

trout, salmon — many teleosts

T/F Both posterior body and tail contribute forward thrust in subcarangiforms.

True

What are some advantages to subcarangifrom swimming?

-good balance of efficiency

-speed

-maneuverability

Are subcarangiforms able to rapidly accelerate from a dead start?

yes, due to low aspect ratio tail

What part of the body undulates in carangiform swimmers?

posterior ½ - ¼ of body

T/F Carangiforms have a very flexible body.

False, they have a moderately stiff body

What part of the body is used in carangiforms?

posterior body and tail contribute to thrust—mostly the tail

Carangiforms are very fast, but what do they sacrifice to be that?

-efficiency

-maneuverability

Carangiform fish have a higher aspect ratio tail. How does this benefit them?

better for sustained high-speed swimming

What are some examples of thunniform swimmers?

mackerel sharks, billfishes, tuna

T/F Thunniforms have inflexible bodies.

true

What part of the body is used for propulsion on thunniforms?

a stiff sickle-shaped caudal fin

Does a thunniforms have a high-aspect ratio or low-aspect ratio tail? What does this help with?

High aspect ratio tail—helps with propulsion

T/F Thunniforms are very efficient and fast, but take time to accelerate from a stop.

true

what oscillations are found in ostraciiform?

tail oscillations

examples of ostraciiform swimmers.

boxfish, torpedo rays

Why do ostraciiforms only move their tails for propulsion?

electricity producing/sensing fish need to keep their body straight to sense electrical fields

Examples of organisms that are tetradontiform and balistiform

-puffers, triggerfishes, ocean sunfishes

How do tetraodontiforms and balistiforms swim?

by flapping their dorsal and anal fins synchronously

Examples of rajiforms.

skates and rays

How do rajiforms swim?

undulations along margins of pectoral fins

examples of amiiforms.

bowfin, seahorses

How do amiiforms swim?

undulations passing along dorsal fin

examples of gymnotiforms.

knife fish, featherfins

How do gymnotiforms swim?

undulations passing along the anal fin

examples of Labriforms.

chimaeras, surfperches, wrasses, parrotfish

How do labriforms swim?

rowing with pectoral fins

T/F Most elasmobranchs swim via undulations

True

How does pressure help with the swimming of sharks?

-increasing internal pressure + increasing speed = stiffening of sharks skin

-acts as secondary attachment for swimming muscles