The name Echinoderm translates directly to “spiky skin”. All echinoderms have a shell, which is composed mainly of calcium carbonate. This shell is then covered with skin(www.oceanicresearch.org).
The skin cells maintain the echinoderm’s exterior, give the organism its color, sense motion, and sometimes release toxins or sticky fluids (www.mesa.edu).
Most echinoderms have a mouth on the bottom and an anus on top. But, for some sea urchins, feather stars, and sea cucumbers, there is one opening for both feeding and excretion. (www.mesa.edu). Internally, Echinoderms are composed of various tube systems that carry out the rest of their bodily functions. Echinoderms have radial symmetry, although they evolved from ancestors that had bilateral symmetry (faculty.clintoncc.suny.edu) Many have either five arms or arms that are a multiple of five.
The skin cells maintain the echinoderm’s exterior, give the organism its color, sense motion, and sometimes release toxins or sticky fluids (www.mesa.edu).
Most echinoderms have a mouth on the bottom and an anus on top. But, for some sea urchins, feather stars, and sea cucumbers, there is one opening for both feeding and excretion. (www.mesa.edu). Internally, Echinoderms are composed of various tube systems that carry out the rest of their bodily functions. Echinoderms have radial symmetry, although they evolved from ancestors that had bilateral symmetry (faculty.clintoncc.suny.edu) Many have either five arms or arms that are a multiple of five.