tube foot

Học thuật
Thân thiện
Definition

Noun: A tube foot is a small, flexible, water-filled tube that is part of the hydraulic system found in echinoderms, such as starfish, sea urchins, and sea cucumbers. It typically ends in a suction cup-like structure and is used for movement, feeding, and gas exchange.

Examples of Usage
  • The starfish uses its tube feet to slowly crawl across the ocean floor.
  • Each tube foot can extend, attach to a surface with its sucker, and then contract to pull the animal forward.
  • In sea urchins, tube feet protruding through holes in the shell are also important for respiration.
Advanced Usage
  • "Operate by hydraulic pressure": The movement of a tube foot is not controlled by muscles in the tube itself but by changes in water pressure within the animal's internal water vascular system.
    • The sea star's locomotion depends on the coordinated hydraulic operation of hundreds of tube feet.
Variants and Related Words
  • Podia (plural of podium): This is the scientific/zoological term often used interchangeably with "tube feet."
  • Water vascular system: The internal network of fluid-filled canals that powers the tube feet.
Synonyms
  • Podium (in zoological context)
Related Phrases
  • "To extend/retract its tube feet": A common phrase describing the basic action of these structures.
    • The sea cucumber extended its tube feet to gather food particles from the sediment.
Noun
  1. tentacular tubular process of most echinoderms (starfish and sea urchins and holothurians) having a sucker at the end and used for e.g. locomotion and respiration