The Swim Bladder of Ray-Finned Fishes

Question

The swim bladder of ray-finned fishes
A)was probably modified from simple lungs of chondrichthyans.
B)developed into lungs in saltwater fishes.
C)first appeared in sharks.
D)provides for regulation of buoyancy.
E)Two of the options listed are correct.

Accepted Answer

The swim bladder of ray-finned fishes provides for regulation of buoyancy, allowing them to control their depth in the water column. It was not modified from the simple lungs of chondrichthyans, which are cartilaginous fishes like sharks. Additionally, the swim bladder did not develop into lungs in saltwater fishes.