The gill lamellae are positioned so the water flows though the gills in the opposite direction of the blood, allowing the blood to pull proportionately more oxygen from the water. This mechanism is called? 

What is the name of the structure shown?

The nares contain what type of sensory receptors? 

Which of the following best describes the structure and function of myomeres? 

What is the carrying capacity for the mixed culture of P. aurelia.

Which of the following is a function of the pereopods? 

In lichens, the fungi provide __________, and the algae/cyanobacteria provide ______. 

Uropod’s, as with other appendages of the crayfish, have a basal protopodite and two distal lobes or branches; such appendages are referred to as 

The small pits in the scales are mechanoreceptors called

Which of the following is a function of the pereopods?