Which feature is characteristic of bony fish but not typical of cartilaginous fish?

Which feature is characteristic of bony fish but not typical of cartilaginous fish?

• A. Lateral Line System
• B. Gills
• C. Swim Bladder for Buoyancy
• D. Cartilage Skeleton

Answer: (C)

Buoyancy control through an internal gas-filled swim bladder is a hallmark of bony fish. This organ can be filled with or released from gas to adjust the fish’s density, allowing precise vertical positioning with little energy. Cartilaginous fish, on the other hand, typically lack a true swim bladder and rely on other means—such as a large oil-rich liver and continuous swimming—to manage buoyancy, so this feature is not typical for them. Lateral line systems and gills are common to both groups, while a cartilage skeleton is characteristic of cartilaginous fish rather than bony fish.

Buoyancy control through an internal gas-filled swim bladder is a hallmark of bony fish. This organ can be filled with or released from gas to adjust the fish’s density, allowing precise vertical positioning with little energy. Cartilaginous fish, on the other hand, typically lack a true swim bladder and rely on other means—such as a large oil-rich liver and continuous swimming—to manage buoyancy, so this feature is not typical for them. Lateral line systems and gills are common to both groups, while a cartilage skeleton is characteristic of cartilaginous fish rather than bony fish.