Fish Flashcards
How do fish breathe?
By ventilating their gills.
Why do fish have features to maximise the rate of gas exchange?
The concentration of O2 in water is lower in the air.
What are the main features of fish used for ventilation/ gas exchange?
-Gill Arch
-Buccal Cavity
-Operculum
-Blood Vessels
-Primary Lamellae (gill filaments)
-Secondary Lamellae (gill plate)
What is the function of the operculum?
Protection of the gills
What is counter current flow and why is it more efficient than parallel flow?
Where bloods flows in opposite direction to water and it maintains a favourable concentration gradient throughout organism.
How do highly active fish increase their uptake of oxygen?
Swim with mouths open to maintain a high rate of water flow over gills. (Shark and Mackerel)
What is the first step in fish inhalation?
The fish opens its mouth, lowering the floor of the buccal cavity.
What is the second step in fish inhalation?
This increases the volume (and decreases the pressure) inside the buccal cavity.
What is the third step in fish inhalation?
Water enters the mouth.
What is the first step in fish exhalation?
Fish closes its mouth decreasing the volume (and increasing the pressure) of the buccal cavity.
What is the second step in fish exhalation?
Water is forced backwards over the gill filaments.
What is the third step in fish exhalation?
The operculum is forced open, allowing water to leave the gills
What is the first adaptation of fish gills?
Gills have primary and secondary lamellae.
What is the function of this adaptation?
Gills have primary and secondary lamellae.
Maximises the surface area
What is the second adaptation of fish gills?
Lamellae have a rich blood supply.
What is the function of this adaptaion?
Lamellae have a rich blood supply.
Maintains the concentration gradient
What is the third adaptation of fish gills?
The epithelium wall of the lamallae are thin.
What is the function of this adaptation?
The epithelium wall of the lamallae are thin.
Reduces diffusion distance.
What is the fourth adaptation of fish gills?
Water flows unidirectionally over the gills.
What is the function of this adaptation?
Water flows unidirectionally over the gills.
-The exchange medium is fully replaced which maintains the concentration gradient as the water always has as much oxygen as possible.
What is the fifth adaptation?
The tips of the gill filaments overlap slightly.
What is the function of this adaptation?
The tips of the gill filaments overlap slightly
Slows down water movemnt to allow more time for gas exchange.
What is the sixth adaptation?
There are gill rankers in front of the gill filaments.
What is the function of this adaptation?
There are gill rankers in front of the gill filaments.
Filters out sand and debris to prevent it from entering the gills.
