The majority of mollusca species live in marine environments, and many of them are found intertidally, in the shallow subtidal and on the continental shelf.
Mollusca is the term for the phylum of animals containing mollusks. It is very diverse and contains many marine and freshwater organisms. Examples of mollusks are snails, oct…opus, mussels. (MORE)
Are you asking what is the function of the mantle? It produces the shell. actually the mantle is a layer in which the inner organs are secured. and this layer forms a hard ca…lcareous material on its outer side, which consequently forms the shell. (MORE)
Gastropoda -"stomach-foot" -single shell or no shell at all -moves via foot muscular action -does torsion(180 degree counter-clockwise rotation) for defense -largest group -h…as 6 pairs of ganglia connected with nerve cords Bivalvia -has 2 valves(outer shells) -has 1 or 2 adductor muscles -lacks a well-defined head -has 6 pairs of ganglia -mostly are dioecious can perform either internal or external fertilization Cephalopoda -most advanced among the invertebrates -ganglia is numerous -"nerves" are big (MORE)
no starfishes are classified under echinodermata. that is "echin" meanind spiny and "derm" meaning skin. these have dermal calcareous plates and they have tiny spines on their… skin. they also have an an endoskeleton. they usually have mouth on their lower surface and have more than 3 arms with tubular feet underneath. (MORE)