Final answer:
The correct option is C). Bony fishes perform gas exchange using gills with a countercurrent exchange system, while cartilaginous fishes also use gills, sometimes with spiracles for water intake. Bony fishes have a swim bladder for buoyancy, which cartilaginous fishes lack.
Step-by-step explanation:
Bony fishes perform gas exchange primarily through gills, where water is drawn over the gills located in chambers under a muscular flap known as the operculum. This method allows bony fishes to extract oxygen from water and release carbon dioxide, in a process that involves a highly efficient countercurrent exchange system. This system maximizes oxygen uptake by ensuring that water with a higher concentration of oxygen continuously flows over the gills, where blood with a lower concentration of oxygen is present, facilitating diffusion.
On the other hand, cartilaginous fishes, like sharks and rays, also have gills for gas exchange. However, some have additional structures called spiracles which help in the intake of water to the gills especially when they are resting on the ocean floor. In terms of efficiency, while cartilaginous fish also have an effective system of gas exchange, there are some anatomical and physiological differences that distinguish them from bony fishes.
Bony fishes also have structures like a swim bladder, which plays a role in buoyancy control, and scales and mucous glands that aid in reducing drag and osmoregulation. Cartilaginous fishes have skeletons made mostly of cartilage and lack the swim bladder.