Fish biomechanics and locomotion - Part 3 Flashcards
Each fin ray is called a ________, it is made up of two bony halves called ________.
lepidotrich hemitrich(s)
_________ are under muscular control
Hemitrichia
In actinopterygii, every fin ray has ____ parts. _____ and _____ parts.
two
left and right parts
Each fin ray has a small _____ attached to it, on the left and right.
muscle
In ray finned fish, each ray can be __________ controlled.
independently
Fin rays allow for ______-______ control of swimming
fine-scaled
What are the benefits of fins rays?
Fine scale control of direction without changing which trunk muscles are used.
Can still swim fast.
What are the evolutionary trends in locomotion?
Pectoral fins become larger and at a greater angle.
Dorsal fins become doubled and anal fin becomes larger.
Much of the evolution in fish swimming modes has been on the ______ rather than on the _______.
fins
trunk
What were the two things that happened evolutionarily, especially in teleost, for swimming modes.
Explain why.
1 - Pectoral fins got bigger and are attached to the body at a greater angle
- bigger = can push more water
- greater angle and position = more fine scale control of movement
2 - Dorsal and anal fins got bigger and two dorsal fins
- partly to break up turbulent wakes
- more fine scaled control of swimming
Sharks will change _______ of ______ as flow speed changes to provide lift.
Angle of attack
_______ ______ can be used to affect position in the water column
Body position
What is a way to save energy while swimming?
Lift
If a shark wants to go up, how will he change his angle of attack?
Go down?
If want more lift, angle more relative to the water column, this will cause more negative pressure on the top, causing lift and the shark to rise.
Change angle to opposite direction.
Cost of swimming depends on fish _____, _____, ________ of water, and ______ ______.
Fish size
fish shape
temperature of water
swimming mode
What does cost of swimming depend on?
Fish size
fish shape
temperature of water
swimming mode
How does shape affect swimming cost?
More streamlined = save energy
How does size affect swimming cost?
Bigger fish = cost more
How does temperature affect swimming cost?
Mostly affects metabolism and viscosity, generally negligible.
Although, there is an optimal temperature for species to minimize energy use.
Draw the graph for metabolic cost of swimming speed for pelagic fish.
Oxygen consumption on y, swimming speed on x.
At slow speeds - more costly than intermediate speeds
at high speeds - more costly than intermediate speeds
U-shaped graph - costs more at extremes
Explain the metabolic cost for swimming speed graph in metabolic fish.
At slower speed, reduced lift, have to use fins to keep themselves up.
At higher speeds, metabolically taxing.
What are different ways fish can counteract the costs of swimming.
Fish will often swim in a middle zone for speed, where metabolic costs are lower.
Stick to narrow range of swimming speeds and will stay there if nothing else changes.
