bony fish

Question 1

What is the operculum?

Answer 1

a bony flap that covers and protects the gills

Question 2

What does the gill arch support?

Answer 2

the gill filaments

Question 3

What is the primary lamellae?

Answer 3

the gill filaments

Question 4

What is the secondary lamellae?

Answer 4

the surface of the gill filaments is folded even more

Question 5

What is a counter current flow?

Answer 5

when two fluids (blood and water) flow in opposite directions

Question 6

How does a counter current flow work in bony fish?

Answer 6

-blood flows along the gill arch and out along the filaments to the secondary lamellae
-blood then flows through the capillaries in the opposite direction to the flow of water over the lamellae = counter current flow

Question 7

What is the need for a counter current flow?

Answer 7

to maintain a steep concentration gradient that will allow for the absorption of maximum oxygen from the water

Question 8

What is the buccal cavity?

Answer 8

the mouth of the fish

Question 9

How does ventilation occur withing bony fish?

Answer 9

-bony fish can keep water flowing over the gills using a buccal-
opercular pump
-the buccal cavity can change volume
-the floor of the mouth moves down which draws water in
-mouth closes and floor is raised again which pushes water through the gills
-movements of the operculum is coordinated with movement of the buccal cavity so as water is pushed from the buccal cavity, the operculum moves outwards
-this reduces the pressure in the opercular cavity which helps water flow through the gills

Question 10

What is the opercular cavity?

Answer 10

the space under the operculum

Question 11

When the operculum moves outwards, what happens to the pressure in the opercular cavity?

Answer 11

decreases