Fish Natural History: Respiration

Front 1

[ respiration ]

fish must be much more efficient in their...

Back 1

uptake of oxygen (water is oxygen-poor)

Front 2

[ respiration ]

what are gill arches?

Back 2

bony or cartilaginous arches in the throat of fish to which the filaments and rakers of the gills are attached

Front 3

[ respiration ]

function of gill arches

Back 3

provide support for gill filaments

Front 4

[ respiration ]

what are gill filaments?

Back 4

a.k.a. primary lamellae

• fleshy, finger-like projections that form a curtain through which water moves across
• possess secondary lamellae

Front 5

[ respiration ]

function of gill filaments

Back 5

takes up oxygen into blood from water passing through the gills..cartilaginous gas exchange

Front 6

[ respiration ]

secondary lemellae

Back 6

projections on the surface of each primary lamella

Front 7

[ respiration ]

function of secondary lemellae

Back 7

increase surface area to gain efficiency...raised ridges

Front 8

diffusion of gases across the gill membrane is further enhanced by __________________, thereby maximizing the __________________

Back 8

diffusion of gases across the gill membrane is further enhanced by blood in the secondary lamellae flowing in the opposite direction to the water passing over the gills,thereby maximizing the diffusion gradient across the entire lamellar surface

Front 9

[ respiration ]

countercurrent flow

Back 9

water flow and blood flow occurs in opposite directions creating concentration gradient from high to low pressure

Front 10

[ respiration ]

advantage of countercurrent flow

Back 10

ensures that asthe blood picks up oxygen from the water it moves along the exchange surface to an area where the adjacent water has an even higher oxygen concentration...basically oxygenated water is contacting poorly oxygenated blood, thus giving it more oxygen

Front 11

[ respiration ]

what are the 2 basic ways fish move water across gill membranes?

Back 11

1. gill pumping
2. ram ventilation
   

Front 12

[ respiration ]

gill pumping

Back 12

synchronized pressure changes in the buccal and opercular chambers

Front 13

how does gill pumping work?

Back 13

the expansion and contraction of the buccal and opercular chambers is timed so that the pressure in the buccal chamber is greater than the pressure in the opercular chamber, thereby ensuring that the water flows in the anterior to posterior direction throughout the breathing cycle

Front 14

[ respiration ]

ram ventilation

Back 14

• keeping mouth open while swimming
  
• forward movement of the fish keeps water flowing over the gills
  

Front 15

[ respiration ]

aerial respiration

Back 15

• receiving oxygen from atmosphere (supplemental form of getting oxygen)
  
• most are facultative air breathers, but some are obligate air breathers

Front 16

[ respiration ]

facultative vs. obligate aerial respiration

Back 16

• facultative → optional
• obligate → necessary to have access to atmosphere oxygen
  - e.g. South American lungfish