MICROANATOMY

Detailed explanation-1: -Fish respire through gills, which have evolved to extract aqueous oxygen. Fish gills consist of filaments with well-ordered lamellar structures, which play a role in maximizing oxygen diffusion.

Detailed explanation-2: -Each filament has thousands of fine branches (lamellae) that are exposed to the water. The branches contain blood capillaries beneath a thin epithelium that separates the blood from the water, allowing oxygen and carbon dioxide to pass through easily. Not all fish completely rely on their gills to breathe, however.

Detailed explanation-3: -A gill lamella is a plate structure that assists the increase of amount of oxygen intake of the blood in a fish, as it contains blood capillaries. This structure contributes to a large surface area and a short distance for gas exchange to take place, increasing the rate of diffusion.

Detailed explanation-4: -In fish, gill lamellae are used to increase the surface area in contact with the environment to maximize gas exchange (both to attain oxygen and to expel carbon dioxide) between the water and the blood.