[Campbell Biology P.750] Which adaptation is characteristic of cephalopods and supports thei... | Practice Question

Which adaptation is characteristic of cephalopods and supports their active predatory lifestyle?

  • A: The presence of a radula for scraping food from surfaces.
  • B: Gills modified for suspension feeding by trapping food particles in mucus.
  • C: A foot modified into a muscular excurrent siphon for jet propulsion.
  • D: Secretion of strong threads to tether themselves to rocks.

Explanation

The text states: 'The foot of a cephalopod has become modified into a muscular excurrent siphon and part of the tentacles. Squids dart about by drawing water into their mantle cavity and then firing a jet of water through the excurrent siphon; they steer by pointing the siphon in different directions.' This adaptation allows for rapid, active movement, crucial for their predatory lifestyle.