| Description of Stentor niger: Heterotrich ciliates, 200-300 micrometres long when extended. No zoochlorellae. With brown cortical pigment granules, giving the cells a dark yellowish or brownish appearance. Broadly trumpet-shaped in extension, clavate or ovoid when contracted. Single ovoid macronucleus. Typically planktonic, freshwater. Reliably reported only in European waters. |
