NEET BIOLOGY

Detailed explanation-1: -Examples of echinoderms include sea stars, sea urchins, sea cucumbers, brittle stars, and feather stars (Fig. 3.83). Although they may appear very different, echinoderms all have two major defining characteristics that set them apart from all other animals: a water vascular system and five-sided radial symmetry.

Detailed explanation-2: -The phylum echinoderms is divided into five extant classes: Asteroidea (sea stars), Ophiuroidea (brittle stars), Echinoidea (sea urchins and sand dollars), Crinoidea (sea lilies or feather stars), and Holothuroidea (sea cucumbers).

Detailed explanation-3: -The echinoderms (Greek for spiny skin) include sea stars, sea urchins, feather stars, brittle stars and sea cucumbers.

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: -Brittle stars are Echinoderms of the Class Ophiuroidea. The adults are superficially like starfish, but they are a different group, with different larvae. Like other echinoderms, they do have a skeleton of calcareous plates, and radial symmetry.