EVERYDAY SCIENCE

Detailed explanation-1: -The key characteristic of sea stars that distinguishes them from other echinoderm classes includes thick arms (ambulacra; singular: ambulacrum) that extend from a central disk where organs penetrate into the arms. Sea stars use their tube feet not only for gripping surfaces, but also for grasping prey.

Detailed explanation-2: -An echinoderm moves by using many tube feet. Tube feet are small, delicate projections attached along the side of a water-filled tube called a radial canal. Figure 3.85 shows some examples of echinoderm tube feet. Tube feet extend through the small holes in the skeleton to the outside.

Detailed explanation-3: -An echinoderm (/ɪˈkaɪnəˌdɜːrm, ˈɛkə-/) is any member of the phylum Echinodermata (/ɪˌkaɪnoʊˈdɜːrmətə/). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or “stone lilies".

Detailed explanation-4: -Echinodermata: Systematics. In traditional taxonomy, there are five classes of living echinoderms: Crinoidea (sea lilies), Asteroidea (starfish), Ophiuroidea (brittle stars or snake stars), Echinoidea (sea urchins and sand dollars), and Holothuroidea (sea cucumbers).

Detailed explanation-5: -They have a star-like appearance and are spherical or elongated. They are exclusively marine animals. The organisms are spiny-skinned. They exhibit organ system level of organization. They are triploblastic and have a coelomic cavity. The skeleton is made up of calcium carbonate. More items