Catfish have dorsal fin spines, which help defend against predators, and caudal fins, which help to propel the fish through the water. A swim bladder controls how high or low the fish sits in the water and gills allow the fish to breathe by taking oxygen out of the water. Catfish spend most of their lives at the bottom of freshwater lakes and streams. Which catfish trait may change (over many generations) if the pond habitat in which it lives becomes significantly deeper?

Swim bladder

Explanation:

Swim bladder is an organ in bony fishes such as catfish that controls their buoyancy. It is also known as air bladder. The swim bladder contains  gas, mainly oxygen and functions as a hydrostatic organ.

As the fish moves in deeper water, the gas in the swim bladder is contracted which decreases the volume of swim bladder.

i think the answer is b.

hope it

answer; i do believe that the correct answer is; ///mendelian genes are at specific loci on the chromosome and, in turn, segregate during meiosis;