echinodermien
Echinodermien, or echinoderms in English, are a phylum of marine animals characterized by a calcareous endoskeleton, a water vascular system, and pentaradial symmetry as adults. They are deuterostomes, closely related to chordates, and live primarily in marine environments from shallow coastal waters to deep seas.
Five extant classes make up the living echinoderms: Asteroidea (starfish), Echinoidea (sea urchins and sand dollars),
Anatomy and physiology: Echinoderms possess an internal skeleton made of calcareous plates. A distinctive feature is
Ecology and biology: They occupy diverse ecological roles as grazers, detritivores, filter feeders, and predators, contributing
Evolution and conservation: Echinoderms have a rich fossil record dating back to the Early Cambrian. They are