Foraminiferan shell (Spirolina areitinus) Science Image

Ref: 80013975



Foraminiferan shell. Coloured scanning electron micrograph (SEM) of the test (shell) of the Mediterranean foraminiferan, Spirolina areitinus. Foraminifera are single-celled protozoa which construct and inhabit shells composed of several chambers. These are usually penetrated by pores through which the cellular contents is extruded. The organisms live in the sea or salt-water lakes. The shells form an important component of chalk. In previous geological ages foraminifera occurred in such large numbers that their shells, largely of calcium carbonate, have formed fossil deposits seen today as limestone. Magnification: x72 at 6x7cm size.