Tube feet (technically podia) are small active tubular projections on the oral face of an echinoderm, such as the arms of a starfish, or the undersides...

of red or orange, while others are blue, grey or brown. Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or...

echinoderms are the possession of a water vascular system with external tube feet and a calcareous endoskeleton consisting of ossicles connected by a mesh...

centimeters (31 cu in), and 25–30 cm (10–12 in) long. Most possess five rows of tube feet (called "podia"), but Apodida lacks these and moves by crawling; the podia...

10 cm (1 to 4 in) across. Sea urchins move slowly, crawling with their tube feet, and sometimes pushing themselves with their spines. They feed primarily...

pentameric symmetry, which is visible in the five paired rows of podia (tube feet) that run from the anus to the mouth. The size is calculated as the diameter...

appearance. Both arms and pinnules have tube feet along the margins of the ambulacral grooves. The tube feet come in groups of three of different size;...

known as sea pigs. Members of the Elpidiidae have particularly enlarged tube "feet" that have taken on a leg-like appearance, using water cavities within...

A pitot tube (/ˈpiːtoʊ/ PEE-toh; also pitot probe) measures fluid flow velocity. It was invented by French engineer Henri Pitot in the early 18th century...

that helps the starfish differentiate between light and darkness, and tube feet, which enable locomotion. All organs connect to the digestive system in...