Question

Choose the incorrect pair:

• A. Torpedo – claspers
• B. Trygon – poison sting
• C. Exocoetus – no operculum
• D. Scoliodon – placoid scales

Answer 1

The correct option is C

Exocoetus – no operculum

Torpedo, commonly known as electric ray, is a flattened cartilaginous fish famous for its ability to numb other organisms (including humans) by delivering strong electric shocks. Like most cartilaginous fish, the male Torpedo has claspers (structures used to transfer semen into the female's cloaca during mating) near the base of the tail. Trygon (stingray) possesses a stinging spine with a venom gland at its base. Exocoetus is a bony fish and possesses an operculum. Scoliodon is a cartilaginous fish, and has placoid scales all over its skin.