Stentor coeruleus

Stentor coeruleus is a species of protozoan belonging to the genus Stentor. These organisms are characterized by their trumpet shape and are uniformly ciliated, meaning they have short, hairlike organelles called cilia that they use for movement and to sweep food particles into their mouths.12

Stentor species are found in freshwater environments, either swimming freely or attached to submerged vegetation. They can regenerate remarkably well, with small fragments capable of growing into complete organisms, making them subjects of study for regeneration in protozoans.1

S. coeruleus is notable for its size, sometimes reaching up to 2 mm in length, and its distinctive blue color, due to a pigment called stentorin. Ciliates, as a group, are considered complex single-celled organisms that utilize cilia for locomotion and feeding.12