These little creatures are basically shelled protozoans, one celled organisms (Subphylum: Sarcodina – the amoebas). They form shells primarily composed of calcareous material, with siliceous material from sponges, or other organic material. They are mostly sessile (non-moving), but can move with the use of temporary structure called a “pseudopodia”. This little “arm” reaches out and pulls the rest of the critter along. In any event, they are harmless bacterial/detrital consumers. There are many different shell shapes and colors that these guys may have.
Scientific Name: Foraminifera
Prevention: Hard to prevent because they are so small