Sitios

Natural Perspective: Starfish (Class: Asteroidea) - English
URL: http://www.perspective.com/nature/animalia/starfish.html

Photos and a brief description of starfish characteristics.

[ eng ]

Introduction to the Asteroidea - English
URL: http://www.ucmp.berkeley.edu/echinodermata/asteroidea.html

True starfish are classified in the Asteroidea, a group of echinoderms. Unlike the superficially similar brittle stars (Ophiuroidea), true starfish have no sharp demarcation between arms and central body, and they move using tube feet rather than wriggling movements of the whole arms. True starfish and ophiuroids shared a common ancestor in the Ordovician; the fossil starfish pictured above is much more recent, coming from the Eocene of California.

[ eng ]