Modes of Swimming: BCF + MPF Flashcards
Define anguilliform swimming. Give an example
- whole body flexion
- eels/lamprey/lungfish
Anguilliform swimming is assumed inefficient but:
- eels have cost of transport 4-5x less than salmonids
What kind of spawning migration do eels have? What other fish swim like this? when?
- 5k w/o eating (need to be efficient)
- sharks/teleosts at slow speeds
define sub-carangiform swimming
- undulation of posterior 1/3-1/2 of body (caudal fin!)
What fish use sub-carangiform swimming?
- rover-predators such as salmon + bass
- shallow undulatory movement
What is the AR of fish that use sub-carangiform swimming?
- 1-3 in bass and trout
- relatively slow moving and fusiform
Define carangiform swimming
- undulation of posterior 1/3 of body (caudal peduncle + fin)
What fish use carangiform swimming?
- jacks, tuna, mackerel
Amplitude of waves ____ anterior to tail in carangiform swimmers
- increases
(rest of body stable)
In carangiform swimmers, what do finlets do?
- decrease turbulence
What does the narrow caudal peduncle act as in carangiform swimmers?
keel
Lunate caudal fin has ____ AR. Why?
- high
- small SA : max propulsion force, less waste in lat movement (efficient)
Define thunniform swimming
- oscillation of tail
- fast efficient cruising speeds
What fish use thunniform swimming
- billfish and lamnid sharks (INDEPENDENT convergent evolution)
What are the physical attributes of thunniform swimmers?
- low drag (high Re) - fast+large
- lunate caudal fin
What does the lunate caudal fin do for thunniform swimmers?
- high AR = maximizes propulsion and minimizes vortex drag
What is the AR of thunniform fish?
10
Define ostraciform swimming
- sculling with caudal fin (low velocity swimming
What kind of fish are ostraciform swimmers
- boxfish (poor/slow swimmers)
What are the physical attributes of ostraciform swimmers
- isocercal caudal fin (low AR)
- slow -> rely on spines/armour for protection
What does MPF mean?
median or paired fins
Define labriform swimming
- rowing/flapping of pectoral fins (propulsion/maneuvering)
What kind of fish use labriform swimming and where do they usually reside?
- parrotfish
- coral reefs, dense vegetation
Define rajiform swimming
- undulatory waves using enlarged pectoral fins/medial fins
What fish use rajiform pectoral swimming
- skates/rays
What fish use rajiform medial fins?
- knife and triggerfish
What rajiform fin is more efficient
medial fin, backward/fwd movement efficient
What % of fish use BCF propulsion?
- 85%
What % of fish use MPF propulsion?
- 15%
MPF is used more for ___ and ____ than propulsion.
- maneuvering and stabilization
