Taxonomic level: phylum Echinodermata; grade of construction: organs derived from three tissue layers; symmetry: radial, sometimes combined with bilateral; type of gut: blind sac with very reduced anus, or complete with anus; type of body cavity other than gut:
Are echinoderms segmented?
Adult echinoderms lack heads, brains, and segmentation; most of them are radially symmetrical. The body generally has five symmetrically radiating parts, or arms, reflecting the internal organization of the animal.
How many body segments do echinoderms have?
Characteristics of Echinoderms
Echinoderms are characterized by radial symmetry, several arms (5 or more, mostly grouped 2 left - 1 middle - 2 right) radiating from a central body (= pentamerous). The body actually consists of five equal segments, each containing a duplicate set of various internal organs.
