Cartilaginous fish

Created by

mayesha

Cards (9)

what is an example of a cartilaginous fish?
sharks
where are the gills located on cartilaginous fish?
they have gills in 5 spaces on each side, called gill pouches, which open to the outside at gill slits
why are cartilaginous fish’s ventilation system less efficient than that of a bony fish?
they don‘t have a special mechanism to force water over the gills
they have parallel flow
gas exchange in parallel flow doesn’t occur continuously across the whole gill lamella
how does cartilaginous fish not having a specialised mechanism to force water over the gills affect them?
many must keep swimming for ventilation to happen
how does cartilaginous fish having parallel flow affect it?
blood travels through the gill capillaries in the same direction as water travels
oxygen diffuses from where its more concentrated, in the water, to where its less concentrated, in the blood-but this diffusion can only continue until the concentrations are equal
after this the blood can’t pick up anymore oxygen from the water as theres no more concentration gradient
so the blood oxygen concentration is limited to 50% of its maximum value
when does gas exchange occur in cartilaginous fish?
gas exchange in parallel flow doesn’t occur continuously across the whole gill lamella
it only occurs until the oxygen concentration in the blood and water is equal
what is parallel flow?
blood and water flow in the same direction at the gill lamellae, maintaining the concentration gradient for oxygen to diffuse into the blood only up to the point where its concentration in the blood and water is equal
what does this graph show?
it shows that with increased distance along the gill lamella, the concentration of oxygen in the blood goes up and the concentration of oxygen in the water goes down, until they are equal
what direction does carbon dioxide diffuse in parallel flow?
down a concentration gradient in the opposite direction from oxygen, from the blood into the water